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Genomic imprinting, an epigenetic phenomenon that causes the expression of a small set of genes in a parent-of-origin-specific manner, is thought to have co-evolved with placentation. Many imprinted genes are expressed in the placenta, where they play diverse roles related to development and nutrient supply function. However, only a small number of imprinted genes have been functionally tested for a role in nutrient transfer capacity in relation to the structural characteristics of the exchange labyrinthine zone. Here, we examine the transfer capacity in a mouse model deficient for the maternally expressed Phlda2 gene, which results in placental overgrowth and a transient reduction in fetal growth. Using stereology, we show that the morphology of the labyrinthine zone in Phlda2 -/+ mutants is normal at E16 and E19. In vivo placental transfer of radiolabeled solutes 14 C-methyl-D-glucose and 14 C-MeAIB remains unaffected at both gestational time points. However, placental passive permeability, as measured using two inert hydrophilic solutes ( 14 C-mannitol; 14 C-inulin), is significantly higher in mutants. Importantly, this increase in passive permeability is associated with fetal catch-up growth. Our findings uncover a key role played by the imprinted Phlda2 gene in modifying placental passive permeability that may be important for determining fetal growth.

Here, a novel strategy of formulating efficient polymeric carriers based on the already described INU-IMI-DETA for gene material whose structural, functional, and biological properties can be modulated and improved was successfully investigated. In particular, two novel derivatives of INU-IMI-DETA graft copolymer were synthesized by chemical functionalisation with epidermal growth factor (EGF) or polyethylenglycol (PEG), named INU-IMI-DETA-EGF and INU-IMI-DETA-PEG, respectively, in order to improve the performance of already described "inulin complex nanoaggregates" (ICONs). The latter were thus prepared by appropriately mixing the two copolymers, by varying each component from 0 to 100 wt% on the total mixture, named EP-ICONs. It was seen that the ability of the INU-IMI-DETA-EGF/INU-IMI-DETA-PEG polymeric mixture to complex siGL3 increases with the increase in the EGF-based component in the EP-ICONs and, for each sample, with the increase in the copolymer:siRNA weight ratio (R). On the other hand, the susceptibility of loaded siRNA towards RNase decreases with the increase in the pegylated component in the polymeric mixture. At all R values, the average size and the zeta potential values are suitable for escaping from the RES system and suitable for prolonged intravenous circulation. By means of biological characterisation, it was shown that MCF-7 cells are able to internalize mainly the siRNA-loaded into EGF-decorated complexes, with a significant difference from ICONs, confirming its targeting function. The targeting effect of EGF on EP-ICONs was further demonstrated by a competitive cell uptake study, i.e., after cell pre-treatment with EGF. Finally, it was shown that the complexes containing both EGF and PEG are capable of promoting the internalisation and therefore the transfection of siSUR, a siRNA acting against surviving mRNA, and to increase the sensitivity to an anticancer agent, such as doxorubicin.

Glomerular filtration rate (GFR) is an important measure of renal function. Various models for its maturation have recently been compared; however, these have used markers, which are subject to different renal elimination processes. Inulin clearance data (a purer probe of GFR) collected from the literature were used to determine age-related changes in GFR aspects of renal drug excretion in pediatrics. An ontogeny model was derived using a best-fit model with various combinations of covariates such as postnatal age, gestational age at birth, and body weight. The model was applied to the prediction of systemic clearance of amikacin, gentamicin, vancomycin, and gadobutrol. During neonatal life, GFR increased as a function of both gestational age at birth and postnatal age, hence implying an impact of birth and a discrepancy in GFR for neonates with the same postmenstrual age depending on gestational age at birth (ie, neonates who were outside the womb longer had higher GFR, on average). The difference in GFR between pre-term and full-term neonates with the same postmenstrual age was negligible from beyond 1.25 years. Considering both postnatal age and gestational age at birth in GFR ontogeny models is important because postmenstrual age alone ignores the impact of birth. Most GFR models use covariates of body size in addition to age. Therefore, prediction from these models will also depend on the change in anthropometric characteristics with age. The latter may not be similar in various ethnic groups, and this makes the head-to-head comparison of models very challenging., (© 2020 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

The main objective of this work was to prepare inulin (INL)/polyvinyl alcohol (PVA) biomaterials imprinted with arbutin (AR) as the target drug. INL from Jerusalem artichoke flour was extracted with hot water extraction method. INL/PVA biomaterials were synthesized with a casting method and a UV curing. The optimal UV curing time and sodium benzoate content were about 10 min and 0.1 wt%, respectively. The biomaterials were characterized by SEM and FT-IR analysis. Mechanical properties of prepared AR imprinted biomaterials were also investigated. AR release was examined with changes of pH at 36.5 °C. The AR release ratio was also investigated using artificial skin. It was found that AR was released constantly for 40 min. Results of drug release mechanism indicated that AR release followed the Fickian diffusion behavior, whereas drug release using artificial skin followed the non-Fickian diffusion behavior. Tyrosinase inhibitory (%) for AR imprinted biomaterials with/without the addition of GL were 58.8% and 79.2%, respectively., (Copyright © 2018. Published by Elsevier B.V.)

Scope: An underexplored topic is the investigation of health effects of dietary fibers via modulation of human small intestine (SI) microbiota. A few previous studies hint at fermentation of some dietary fibers in the distal SI of humans and pigs. Here the potential of human SI microbiota to degrade dietary fibers and produce metabolites in vitro is investigated., Methods and Results: Fructans, galacto-oligosaccharides, lemon pectins, and isomalto/malto-polysaccharides are subjected to in vitro batch fermentations inoculated with ileostomy effluent from five subjects. Fiber degradation products, formation of bacterial metabolites, and microbiota composition are determined over time. Galacto- and fructo-oligosaccharides are rapidly utilized by the SI microbiota of all subjects. At 5h of fermentation, 31%-82% of galacto-oligosaccharides and 29%-89% fructo-oligosaccharides (degree of polymerization DP4-8) are utilized. Breakdown of fructo-oligosaccharides/inulin DP ≥ 10, lemon pectin, and iso-malto/maltopolysaccharides only started after 7h incubation. Degradation of different fibers result in production of mainly acetate, and changed microbiota composition over time., Conclusion: Human SI microbiota have hydrolytic potential for prebiotic galacto- and fructo-oligosaccharides. In contrast, the higher molecular weight fibers inulin, lemon pectin, and iso-malto/maltopolysaccharides show slow fermentation rate. Fiber degradation kinetics and microbiota responses are subject dependent, therefore personalized nutritional fiber based strategies are required., (© 2020 The Authors. Published by Wiley-VCH GmbH.)

Inulin (IN), as a classic diagnostic for determination of glomerular filtration rate, reached high concentration in kidney. Introducing drug into IN derivatives may be a new method to target kidney for drug delivery. To test the hypothesis, ferulic acid (FeA) was conjugated into IN by ester bond and amide bond (ethylenediamine as spacer), respectively, and the two FeA-IN conjugations, inulin ferulate (IN-FeA) and inulin ethylenediamine ferulate (IN-EDA-FeA) were obtained. NMR spectrum was involved to characterize the conjugations. The FeA in vitro release profiles were tested in mice plasma and renal homogenate. Finally, the biodistribution test was performed to evaluate their renal-targeting ability. Both IN-FeA and IN-EDA-FeA showed a higher release rate of FeA in renal homogenate than in mouse plasma suggesting the conjugates are relatively stable in plasma and more likely FeA release in kidney. The renal area under the curve (AUC) for IN-FeA and IN-EDA-FeA were 539.6 ± 107.9 and 558.5 ± 131.6 μg h/mL, respectively, which were 4.47 and 4.62 times of 120.8 ± 18.1 μg h/mL for free FeA. Meanwhile, significant smaller FeA accumulation in other organs was observed. These data indicated that IN-FeA and IN-EDA-FeA effectively targeted kidney for FeA delivery., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Scope: Inulin-type fructans are commonly applied in infant formula to support development of gut microbiota and immunity. These inulin-type fructans are considered to be fermented by gut microbiota, but it is unknown how fermentation impacts immune modulating capacity and whether the process of fermentation is dependent on the infant's age., Methods and Results: The in vitro fermentation of chicory fructo-oligosaccharides (FOS) and native inulin are investigated using pooled fecal inocula of two- and eight-week-old infants. Both inocula primarily utilize the trisaccharides in FOS, while they almost completely utilize native inulin with degree of polymerization (DP) 3-8. Fecal microbiota of eight-week-old infants degrades longer chains of native inulin up to DP 16. This correlates with a higher abundance of Bifidobacterium and higher production of acetate and lactate after 26 h of fermentation. Fermented FOS and native inulin attenuate pro-inflammatory cytokines produced by immature dendritic cells (DCs), but profiles and magnitude of attenuation are stronger with native inulin than with FOS., Conclusion: The findings demonstrate that fermentation of FOS and native inulin is dependent on the infant's age and fructan structure. Fermentation enhances attenuating effects of pro-inflammatory responses in DCs, which depend mainly on microbial metabolites formed during fermentation., (© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Olive leaves extract (OLE) was spray-dried with maltodextrin (MD) or inulin (IN) to study the evolution of oleuropein (OE) during in vitro gastrointestinal digestion, its bioaccessibility and potential bioavailability. In the case of OLE-MD, OE was partially degraded in gastric and intestinal conditions; whereas in OLE-IN, OE was released under gastric conditions and partially degraded under intestinal conditions. In both cases, the encapsulation of OLE led to higher OE contents at the end of digestion, compared with non-encapsulated OLE, suggesting a protective role of the polysaccharides by the formation of non-covalent polysaccharides-OE complexes. OE bioaccessibility was ten times higher (p ≤ 0.05) in OLE-MD and OLE-IN than in non-encapsulated OLE. However, OE potential bioavailability, evaluated by tangential filtration, was not detected. Encapsulation technology and the encapsulant agent used may determine the release of the encapsulated compounds at a specific-site and their effect on health., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In the present study, the influences of diets (i.e. chow and AIN-93 diets) on the interpretation of various fecal parameters including viable microbiota, moisture, weight, and short-chain fatty acids in rats fed different amounts of inulin (0.5-2 g/kg). Eight groups of rats (n = 8/group) were fed, for 4 weeks, chow or AIN-93 diets with or without inulin supplementation. Fecal samples were analyzed for different fecal parameters. After a 2-week adaptation, apparent differences in some fecal parameters were observed between the chow and AIN-93 diet groups. Throughout the 4-week intervention period, significantly (p < 0.05) higher Lactobacillus spp. counts, fecal moisture (∼2.7-fold), and fecal weight (∼5.8-fold) were observed with chow diet over AIN-93 diet. More specifically, significant elevations in the levels of Bifidobacterium spp., Lactobacillus spp., fecal moisture, and fecal weight could be observed at low-dose (0.5 g/kg) of inulin in chow diet groups, while most of these changes could merely be seen at medium-dose (1 g/kg) in AIN-93 diet groups. These results demonstrated that the choice of experimental diets would affect the comparison of fecal parameters as well as the interpretation of effective dosage of prebiotic in intestinal health assessments., (Copyright © 2019. Published by Elsevier Taiwan LLC.)

Probiotics show low cell viability after oral administration because they have difficulty surviving in the stomach due to low pH and enzymes. For the oral delivery of probiotics, developing a formula that protects the probiotic bacteria from gastric acidity while providing living cells is mandatory. In this study, we developed tablets using a new pH-sensitive phthalyl inulin (PI) to protect probiotics from gastric conditions and investigated the effects of different compression forces on cell survival. We made three different tablets under different compression forces and measured survivability, disintegration time, and kinetics in simulated gastric-intestinal fluid. During tableting, there were no significant differences in probiotic viability among the different compression forces although disintegration time was affected by the compression force. A higher compression force resulted in higher viability in simulated gastric fluid. The swelling degree of the PI tablets in simulated intestinal fluid was higher than that of the tablets in simulated gastric fluid due to the pH sensitivity of the PI. The probiotic viability formulated in the tablets was also higher in acidic gastric conditions than that for probiotics in solution. Rapid release of the probiotics from the tablet occurred in the simulated intestinal fluid due to the pH sensitivity. After 6 months of refrigeration, the viability of the PI probiotics was kept. Overall, this is the first study to show the pH-sensitive properties of PI and one that may be useful for oral delivery of the probiotics.

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain barrier. However, there have been few reports regarding not only the quantitative analysis but also optimal administration conditions and dosing regimens for investigations of nose-to-brain delivery. The limited progress in research on nose-to-brain pathway mechanisms using rodents represents a significant impediment in terms of designing nose-to-brain delivery systems for candidate drugs. To gain some headway in this regard, we developed and evaluated two novel methods of stable intranasal administration under inhalation anesthesia for experimental animals. We also describe a method for the evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radio-labeled [ 14 C]-inulin (molecular weight: 5,000) as a model substrate of water-soluble macromolecules. Initially, we developed a pipette-based intranasal administration protocol using temporarily openable masks, which enabled us to perform reliable administration to animals under stable anesthesia. Using this system, [ 14 C]-inulin could be delivered to the brain with little experimental error. We subsequently developed an intranasal administration protocol entailing reverse cannulation from the airway side through the esophagus, which was developed to minimize the effects of mucociliary clearance (MC). This technique led to significantly higher levels of [ 14 C]-inulin, which was quantitatively detected in the olfactory bulb, cerebrum, and medulla oblongata, than the pipette method. This appears to be because retention of the drug solution in the nasal cavity was substantially increased by active administration using a syringe pump in a direction opposite to the MC into the nasal cavity. In conclusion, the two methods of intranasal administration developed in this study can be expected to be extremely useful techniques for evaluating pharmacokinetics in rodents. The reverse cannulation method, in particular, could be useful for evaluating the full potential of nose-to-brain delivery of drug candidates.

Inulin-type fructooligosaccharides (FOS) purified from Morinda Officinalis, with degrees of polymerization (DP) from 3 to 9, have been approved in China as an oral prescribed drug for mild and moderate depression episode, while the stability and oral absorption of this FOS mixtures are largely unknown. As the main active component and quality control marker for above FOS, DP5 was selected as the representative FOS in this study. Desalting method by ion exchange resin was developed to treat bio-sample, followed by separation and quantification by high performance liquid chromatography-charged aerosol detector. Results showed that the DP5 was stepwisely hydrolyzed in simulated gastric fluid and gut microbiota, while maintained stable in intestinal fluid. DP5 has poor permeability across Caco-2 monolayer with P app of 5.22 × 10 -7  cm/s, and very poor oral absorption with bioavailability of (0.50 ± 0.12)% in rat. In conclusion, FOS in Morinda Officinalis demonstrated poor chemical stability in simulated gastric fluid and human gut microbiota, and low oral absorption in rats., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The environmental fates of pharmaceuticals and the effects of crop protection products on non-target species are subjects that are undergoing intense review. Since measuring the concentrations and effects of xenobiotics on all affected species under all conceivable scenarios is not feasible, standard laboratory animals such as rabbits are tested, and the observed adverse effects are translated to focal species for environmental risk assessments. In that respect, mathematical modelling is becoming increasingly important for evaluating the consequences of pesticides in untested scenarios. In particular, physiologically based pharmacokinetic/toxicokinetic (PBPK/TK) modelling is a well-established methodology used to predict tissue concentrations based on the absorption, distribution, metabolism and excretion of drugs and toxicants. In the present work, a rabbit PBPK/TK model is developed and evaluated with data available from the literature. The model predictions include scenarios of both intravenous (i.v.) and oral (p.o.) administration of small and large compounds. The presented rabbit PBPK/TK model predicts the pharmacokinetics (Cmax, AUC) of the tested compounds with an average 1.7-fold error. This result indicates a good predictive capacity of the model, which enables its use for risk assessment modelling and simulations.

Hagfish are osmoconformers, maintaining an internal osmolality that matches their seawater habitats. Hagfish would, therefore, appear to have no physiological need to drink, but previous studies are equivocal regarding whether drinking in hagfish occurs. The current study addressed this knowledge gap, by examining drinking and water permeability in the Pacific hagfish, Eptatretus stoutii. One-third of analysed hagfish were shown to accumulate radiolabelled drinking rate markers (tritiated inulin and polyethylene glycol-4000) in their gut tissues; however, this was attributed to the presence of markers in the blood perfusing the digestive tract, following absorption through paracellular pathways at the gill. No accumulation of marker was observed in hagfish subjected to more dilute (75% seawater) or more concentrated (125% seawater) media. Diffusive water efflux, measured by tritiated water washout, was shown to be very high, with 50% of body water exchanged within 14 to 16 min, depending on exposure salinity. In full-strength seawater, the total exchangeable pool of water was 78% of hagfish mass. We conclude that hagfish do not drink, and their high water permeability is likely to result in rapid osmotic equilibration under circumstances where perturbations may occur.

Endogenous markers of kidney function are insensitive to early declines in glomerular filtration rate (GFR) and in rodent models, validated, practical alternatives are unavailable. In this study, we determined GFR by modeling the plasma clearance of two compounds, iohexol and inulin, and compared the findings to common endogenous markers. All plasma clearance methods of both iohexol and inulin detected a decline in renal function weeks prior to any increase in endogenous marker. Iohexol plasma clearance and inulin plasma clearance had a very high agreement and minimal bias when using 12-sample models. However, only iohexol could be accurately simplified to a two-sample, one-compartment estimation strategy. Following an IV injection of low-dose iohexol and two timed blood samples at 30 and 90 min, one can accurately approximate a complex 12-sample strategy of plasma clearance. This method is simple enough to use in routine, longitudinal analysis of larger cohort animal studies., (© 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.)

Here, long-circulating behaviors of Inulin-based nanomicelles are demonstrated for the first time in vivo. We show the synthesis and evaluation of biotin (BIO)-decorated polymeric INVITE micelles constituted of substances of natural origin, Inulin (INU) and Vitamin E (VITE), as long-circulating carriers for receptor-mediated targeted drug delivery. The resulting INVITE or INVITE-BIO micelles, nanometrically sized, did not reveal any cytotoxicity after 24h of incubation with Caco-2 cells. Moreover, in vitro studies on Caco-2 cells monolayers indicated that the transport of INVITE-BIO micelles was faster than surface unmodified INVITE micelles. In vivo optical imaging studies evidenced that, upon intravenous administration, INVITE-BIO micelles were quantitatively present in the body up to 48h. Instead, after oral administration, the micelles were not found in the systemic circulation but eliminated with the normal intestinal content. In conclusion, INVITE-BIO micelles may enhance drug accumulation in tumor-cells over-expressing the receptor for biotin through receptor mediated endocytosis., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background/aims: Maternal hypercholesterolemia is a risk factor to renal injury in rat pups at adulthood, especially if they feed a cholesterol-enriched diet after weaning. However, the renal function of male pups of dams with hypercholesterolemia (PH) that were fed a regular chow from weaning to adulthood needs investigation, particularly those exposed to an adverse risk such as nicotine., Methods: We evaluated the renal function of PH animals and we compared the data with those found in male pups of control dams (PC) at 3- and 6-month-old by inulin clearance. Moreover, we investigated the effect of nicotine treatment for 8 days in both PH and PC animals at 6 months old via metabolic function studies and by renal histological analysis., Results: Inulin clearance and other renal function parameters were similar in PH and PC animals at 3 and 6 months old. Nevertheless, the PH group showed significant differences with regard to histological analysis despite a similar number of glomeruli. The glomerular area of PH animals was significantly smaller than that measured in PC animals, and the fractional interstitial area was significantly larger in PH animals than that measured in PC animals at 3 months old. With regard to nicotine treatment, we observed a trend for a reduction in creatinine clearance in both PC and PH groups, but only PH animals showed hypomagnesemia and the highest fractional interstitial area., Conclusions: The offspring exposed to a high cholesterol milieu during intrauterine and neonatal life may show a silent kidney injury at adulthood that may be aggravated by nicotine exposure if hypomagnesemia occurs., (© 2017 The Author(s). Published by S. Karger AG, Basel.)

Background: Disruption of epithelial tight junctions (TJ), gut barrier dysfunction and endotoxemia play crucial role in the pathogenesis of alcoholic tissue injury. Occludin, a transmembrane protein of TJ, is depleted in colon by alcohol. However, it is unknown whether occludin depletion influences alcoholic gut and liver injury., Methods: Wild type (WT) and occludin deficient (Ocln(-/-)) mice were fed 1-6% ethanol in Lieber-DeCarli diet. Gut permeability was measured by vascular-to-luminal flux of FITC-inulin. Junctional integrity was analyzed by confocal microscopy. Liver injury was assessed by plasma transaminase, histopathology and triglyceride analyses. The effect of occludin depletion on acetaldehyde-induced TJ disruption was confirmed in Caco-2 cell monolayers., Results: Ethanol feeding significantly reduced body weight gain in Ocln(-/-) mice. Ethanol increased inulin permeability in colon of both WT and Ocln(-/-) mice, but the effect was 4-fold higher in Ocln(-/-) mice. The gross morphology of colonic mucosa was unaltered, but ethanol disrupted the actin cytoskeleton, induced redistribution of occludin, ZO-1, E-cadherin and β-catenin from the junctions and elevated TLR4, which was more severe in Ocln(-/-) mice. Occludin knockdown significantly enhanced acetaldehyde-induced TJ disruption and barrier dysfunction in Caco-2 cell monolayers. Ethanol significantly increased liver weight and plasma transaminase activity in Ocln(-/-) mice, but not in WT mice. Histological analysis indicated more severe lesions and fat deposition in the liver of ethanol-fed Ocln(-/-) mice. Ethanol-induced elevation of liver triglyceride was also higher in Ocln(-/-) mice., Conclusion: This study indicates that occludin deficiency increases susceptibility to ethanol-induced colonic mucosal barrier dysfunction and liver damage in mice., (Published by Elsevier B.V.)

Aims: To find an explanation for the lower potency of insulin detemir observed in humans compared with unmodified human insulin by investigating insulin detemir and human insulin concentrations directly at the level of peripheral insulin-sensitive tissues in humans in vivo., Methods: Euglycaemic-hyperinsulinaemic clamp experiments were performed in healthy volunteers. Human insulin was administered i.v. at 6 pmol/kg/min and insulin detemir at 60 pmol/kg/min, achieving a comparable steady-state pharmacodynamic action. In addition, insulin detemir was doubled to 120 pmol/kg/min. Minimally invasive open-flow microperfusion (OFM) sampling methodology was combined with inulin calibration to quantify human insulin and insulin detemir in the interstitial fluid (ISF) of subcutaneous adipose and skeletal muscle tissue., Results: The human insulin concentration in the ISF was ∼115 pmol/l or ∼30% of the serum concentration, whereas the insulin detemir concentration in the ISF was ∼680 pmol/l or ∼2% of the serum concentration. The molar insulin detemir interstitial concentration was five to six times higher than the human insulin interstitial concentration and metabolic clearance of insulin detemir from serum was substantially reduced compared with human insulin., Conclusions: OFM proved useful for target tissue measurements of human insulin and the analogue insulin detemir. Our tissue data confirm a highly effective retention of insulin detemir in the vascular compartment. The higher insulin detemir relative to human insulin tissue concentrations at comparable pharmacodynamics, however, indicate that the lower potency of insulin detemir in humans is attributable to a reduced effect in peripheral insulin-sensitive tissues and is consistent with the reduced in vitro receptor affinity., (© 2015 John Wiley & Sons Ltd.)

Using rats fed 22 g/d of a control diet containing 0.005% zinc (Zn) or 2 Zn-excess diets containing 0.05% or 0.2% Zn for 4 weeks, we examined the mechanisms involved in the deterioration of renal function induced by Zn-excess intake. An increase in Zn intake elevated mean blood pressure (BP) and reduced renal blood flow (RBF) and inulin clearance in a dose-dependent manner. This decline in inulin clearance may be derived from a fall in RBF. Administration of the nitric oxide (NO) synthase inhibitor, N ω -nitro-l-arginine methyl ester, markedly increased mean BP and significantly decreased RBF in the 3 groups of rats. Administration of the exogenous superoxide radical (OO - ) scavenger, tempol, significantly decreased mean BP and substantially increased RBF in all groups of rats. These observations suggest that both an elevation in systemic BP and a reduction in RBF seen in the 2 Zn-excess diet groups result from a decrease in the action of the vasodilator, NO, through the formation of peroxynitrite based on the nonenzymatic reaction of NO and increased OO - Indeed, the activity of the endogenous OO - scavenger, copper/Zn-superoxide dismutase, was significantly reduced in the vessel wall of rats fed 2 Zn-excess diets versus a control diet. 8-Hydroxy-2'-deoxyguanosine formation caused by OO - generation was notably elevated in the kidneys of rats fed 2 Zn-excess diets relatively to rats fed a control diet. Thus, Zn-excess intake leads to the aggravation of renal function concomitantly with an increase in systemic BP predominantly through the oxidative stress caused by OO^{., (© The Author(s) 2014.)}

Treatment of patients with acute liver failure (ALF) is unsatisfactory and mortality remains unacceptably high. Blocking NMDA receptors delays or prevents death of rats with ALF. The underlying mechanisms remain unclear. Clarifying these mechanisms will help to design more efficient treatments to increase patient's survival. The aim of this work was to shed light on the mechanisms by which blocking NMDA receptors delays rat's death in ALF. ALF was induced by galactosamine injection. NMDA receptors were blocked by continuous MK-801 administration. Edema and cerebral blood flow were assessed by magnetic resonance. The time course of ammonia levels in brain, muscle, blood, and urine; of glutamine, lactate, and water content in brain; of glomerular filtration rate and kidney damage; and of hepatic encephalopathy (HE) and intracranial pressure was assessed. ALF reduces kidney glomerular filtration rate (GFR) as reflected by reduced inulin clearance. GFR reduction is due to both reduced renal perfusion and kidney tubular damage as reflected by increased Kim-1 in urine and histological analysis. Blocking NMDA receptors delays kidney damage, allowing transient increased GFR and ammonia elimination which delays hyperammonemia and associated changes in brain. Blocking NMDA receptors does not prevent cerebral edema or blood-brain barrier permeability but reduces or prevents changes in cerebral blood flow and brain lactate. The data show that dual protective effects of MK-801 in kidney and brain delay cerebral alterations, HE, intracranial pressure increase and death. NMDA receptors antagonists may increase survival of patients with ALF by providing additional time for liver transplantation or regeneration.

Introduction: Previous distribution and histological studies have indicated that the kidneys and renal proximal tubular cells play a role in clearance of rFVIIa. However, the relative importance of the kidneys in clearance of rFVIIa has not previously been addressed. The objective of the present study was to evaluate the importance of the kidneys in the clearance process of rFVIIa after iv administration to rats using a nephrectomy model., Materials and Methods: A nephrectomized rat model was established and validated using inulin, a compound primarily cleared by the kidneys, as a test substance and several physiological parameters were monitored to ensure viability and robustness of the model. The model was then used for pharmacokinetic evaluation of renal clearance of rFVIIa. The pharmacokinetic parameters for rFVIIa were evaluated both by use of standard non-compartmental methods and by use of mixed effects methods, where a pharmacokinetic model was used to simultaneously model all data from healthy, sham operated, and nephrectomized rats., Results: Nephrectomized animals showed stable rectal temperature, SpO2 and pulse and as expected, clearance of inulin was essentially abolished compared to control animals (p<0.001). For rFVIIa, nephrectomy resulted in a clearance and terminal half-life of 34mL/h/kg and 2.8h compared to 68mL/h/kg and1.9h in rats exposed to sham surgery (p<0.0001 for both parameters)., Conclusion: The present data show that about 50% of the total clearance of rFVIIa from circulation in rats under isoflurane anaesthesia is due to renal clearance., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

This study was performed to clarify whether a formula (Holstein equation) based on a single blood sample and the isotonic, nonionic, iodine contrast medium iodixanol in Holstein dairy cows can apply to the estimation of glomerular filtration rate (GFR) for beef cattle. To verify the application of iodixanol in beef cattle, instead of the standard tracer inulin, both agents were coadministered as a bolus intravenous injection to identical animals at doses of 10 mg of I/kg of BW and 30 mg/kg. Blood was collected 30, 60, 90, and 120 min after the injection, and the GFR was determined by the conventional multisample strategies. The GFR values from iodixanol were well consistent with those from inulin, and no effects of BW, age, or parity on GFR estimates were noted. However, the GFR in cattle weighing less than 300 kg, aged<1 yr old, largely fluctuated, presumably due to the rapid ruminal growth and dynamic changes in renal function at young adult ages. Using clinically healthy cattle and those with renal failure, the GFR values estimated from the Holstein equation were in good agreement with those by the multisample method using iodixanol (r=0.89, P=0.01). The results indicate that the simplified Holstein equation using iodixanol can be used for estimating the GFR of beef cattle in the same dose regimen as Holstein dairy cows, and provides a practical and ethical alternative.

Introduction: The present report describes and evaluates a simple protocol for serial measurements of glomerular filtration rate (GFR) and renal plasma flow (RPF) in conscious mice., Methods: In conscious mice, a bolus of [(3)H]methoxy-inulin and [(14)C]para-amino-hippuric (PAH) was injected in the tail vein whereupon eight blood samples were taken during the following 75min. Plasma concentrations were determined by liquid scintillation and clearances of the injected markers were calculated by non-compartmental pharmacokinetic data analysis of the plasma disappearance curves. In anaesthetized mice, the renal extraction ratio of PAH was determined by infusion of PAH and subsequent analysis of blood taken from the carotid artery and the renal vein. The acquired value (0.70±0.02) was used for all subsequent calculations of RPF. To evaluate the protocol, a crossover study was performed where either the vehicle or the angiotensin II AT1 receptor antagonist candesartan was given prior to the clearance measurements., Results: Baseline values of GFR and RPF were in line with those earlier reported in mice. Administration of candesartan increased RPF and reduced the filtration fraction, whereas GFR was unaltered. These changes are supported by earlier findings and demonstrate that GFR and RPF can be determined independently. Furthermore, modelling experiments demonstrated that acceptable results are obtained even if the number of blood samples is reduced to four which is a way to further simplify the procedure., Discussion: The method provides an effective way for repeated measurements of GFR and RPF in mice without potentially confounding effects of anaesthesia., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We recently reported on the physical characteristics of photo-triggerable liposomes containing dipalmitoylphosphatidylcholine (DPPC), and 1,2-bis (tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine (DC(8,9)PC) carrying a photo agent as their payload. When exposed to a low-intensity 514 nm wavelength (continuous-wave) laser light, these liposomes were observed to release entrapped calcein green (Cal-G; Ex/Em 490/517 nm) but not calcein blue (Cal-B; Ex/Em 360/460 nm). In this study, we have investigated the mechanism for the 514 nm laser-triggered release of the Cal-G payload using several scavengers that are known specifically to inhibit either type I or type II photoreaction pathways. Liposomes containing DPPC:DC(8,9)PC: distearoylphosphatidylethanolamine (DSPE)-polyethylene glycol (PEG)-2000 (86:10:04 mole ratio) were loaded either with fluorescent (calcein) or nonfluorescent ((3)H-inulin) aqueous markers. In addition, a non-photo-triggerable formulation (1-palmitoyl-2-oleoyl phosphatidylcholine [POPC]:DC(8,9)PC:DSPE-PEG2000) was also studied with the same payloads. The 514 nm wavelength laser exposure on photo-triggerable liposomes resulted in the release of Cal-G but not that of Cal-B or (3)H-inulin, suggesting an involvement of a photoactivated state of Cal-G due to the 514 nm laser exposure. Upon 514 nm laser exposures, substantial hydrogen peroxide (H2O2, ≈100 μM) levels were detected from only the Cal-G loaded photo-triggerable liposomes but not from Cal-B-loaded liposomes (≤10 μM H2O2). The Cal-G release from photo-triggerable liposomes was found to be significantly inhibited by ascorbic acid (AA), resulting in a 70%-80% reduction in Cal-G release. The extent of AA-mediated inhibition of Cal-G release from the liposomes also correlated with the consumption of AA. No AA consumption was detected in the 514 nm laser-exposed Cal B-loaded liposomes, thus confirming a role of photoactivation of Cal-G in liposome destabilization. Inclusion of 100 mM K3Fe(CN)6 (a blocker of electron transfer) in the liposomes substantially inhibited Cal-G release, whereas inclusion of 10 mM sodium azide (a blocker of singlet oxygen of type II photoreaction) in the liposomes failed to block 514 nm laser-triggered Cal-G release. Taken together, we conclude that low-intensity 514 nm laser-triggered release of Cal-G from photo-triggerable liposomes involves the type I photoreaction pathway.

Background: Application of a multisample method using inulin to estimate glomerular filtration rate (GFR) in cats is cumbersome., Objectives: To establish a simplified procedure to estimate GFR in cats, a single-blood-sample method using inulin was compared with a conventional 3-sample method., Animals: Nine cats including 6 clinically healthy cats and 3 cats with spontaneous chronic kidney disease., Methods: Retrospective study. Inulin was administered as an intravenous bolus at 50 mg/kg to cats, and blood was collected at 60, 90, and 120 minutes later for the 3-sample method. Serum inulin concentrations were colorimetrically determined by an autoanalyzer method. The GFR in the single-blood-sample method was calculated from the dose injected, serum concentration, sampling time, and estimated volume of distribution on the basis of the data of the 3-sample method., Results: An excellent correlation was observed (r = 0.99, P = .0001) between GFR values estimated by the single-blood-sample and 3-sample methods., Conclusions and Clinical Importance: The single-blood-sample method using inulin provides a practicable and ethical alternative for estimating glomerular filtration rate in cats., (Copyright © 2012 by the American College of Veterinary Internal Medicine.)

Biopolymers composed of a pH-responsive, hydrophilic poly(methacrylic acid-grafted-ethylene glycol) network polymerized in the presence of poly(methyl methacrylate) nanoparticles were designed for the oral delivery of chemotherapeutics for the treatment of colon cancer. An inulin-doxorubicin conjugate, designed to target the colon and improve doxorubicin efficacy, was loaded into these polymer carriers at an efficiency of 54%. Release studies indicated these polymer carriers minimized conjugate release in low pH conditions and released the conjugate at neutral pH conditions using a two-step pH experiment modeling the stomach and the small intestine. At lower concentration levels, the presence of the polymer carriers did not disrupt tight junctions as determined by transepithelial electrical resistance studies using Caco-2 and HT29-MTX cell lines which are an accurate model of the GI tract epithelia. Permeability values of unmodified doxorubicin and the inulin-doxorubicin conjugate in the presence of the polymer carriers were also determined using the same cell models and ranged from 1.87 to 3.80 × 10 (-6) cm/s.

Background: The natriuretic/diuretic response to atrial natriuretic peptide (ANP), an important regulator of water and Na(+) balance, is markedly attenuated in nephrotic syndrome (NS). It has been suggested that the diminished renal responsiveness to ANP may contribute to the pathogenesis of salt retention and edema formation in NS. However, the mechanisms underlying the renal hyporesponsiveness to ANP remain largely unknown., Methods: The acute effects of exogenous infusion of ANP (5 µg/kg + 10 µg/kg/h) were studied by clearance methodology in control rats, hypoalbuminemic rats with Adriamycin (ADR)-induced NS and in ADR-treated rats infused with hyperoncotic albumin sufficient to restore plasma albumin to normal levels., Results: Administration of ANP to control rats resulted in a significant increase in urinary flow rate, absolute rate of sodium excretion (+456%) and glomerular filtration rate (GFR). Mean arterial blood pressure decreased following infusion of the peptide. In the nephrotic rats, baseline GFR and Na(+) excretion were significantly lower than in the control animals, and the renal effects of ANP were markedly blunt compared to the control animals. In contrast, the hypotensive effect of ANP in the ADR-treated rats was largely preserved. Infusion of hyperoncotic albumin prior to ANP administration reversed the decrease in baseline GFR and Na(+) excretion and completely restored the renal effects of ANP in the nephrotic rats., Conclusion: These findings indicate that renal hyporesponsiveness to ANP in rats with ADR-induced NS is a reversible phenomenon that appears to be of functional origin rather than reflecting permanent cellular damage., (© 2013 S. Karger AG, Basel.)

Background: The combined serum creatinine (SCreat) and cystatin C (CysC) CKD-EPI formula constitutes a new advance for glomerular filtration rate (GFR) estimation in adults. Using inulin clearances (iGFRs), the revised SCreat and the combined Schwartz formulas, this study aims to evaluate the applicability of the combined CKD-EPI formula in children., Method: 201 iGFRs for 201 children were analyzed and divided by chronic kidney disease (CKD) stages (iGFRs ≥90 ml/min/1.73 m(2), 90 > iGFRs > 60, and iGFRs ≤59), and by age groups (<10, 10-15, and >15 years). Medians with 95% confidence intervals of bias, precision, and accuracies within 30% of the iGFRs, for all three formulas, were compared using the Wilcoxon signed-rank test., Results: For the entire cohort and for all CKD and age groups, medians of bias for the CKD-EPI formula were significantly higher (p < 0.001) and precision was significantly lower than the solely SCreat and the combined SCreat and CysC Schwartz formulas. We also found that using the CKD-EPI formula, bias decreased and accuracy increased while the child age group increased, with a better formula performance above 15 years of age. However, the CKD-EPI formula accuracy is 58% compared to 93 and 92% for the SCreat and combined Schwartz formulas in this adolescent group., Conclusions: The performance of the combined CKD-EPI formula improves in adolescence compared with younger ages. Nevertheless, the CKD-EPI formula performs more poorly than the SCreat and the combined Schwartz formula in pediatric population., (© 2013 S. Karger AG, Basel.)

To estimate the glomerular filtration rate (GFR) in conscious rabbits, a single-sample method using the non-ionic contrast medium iodixanol was compared with a three-sample method using the standard agent inulin. Iodixanol and inulin were co-administered intravenously to male New Zealand White rabbits at 60 mg I/kg and 40 mg/kg, respectively, and blood was collected 30, 60, 90 and 120 min later. Serum iodixanol and inulin concentrations were separately determined by high performance liquid chromatography and colorimetry, respectively. Serum urea nitrogen (UN) and creatinine concentrations were also determined. Based on the data from healthy and cisplatin-treated rabbits, the GFR estimated by iodixanol was well consistent with that by inulin. Further, when the GFR decreased to more than 60% of the reference value, serum creatinine concentrations became elevated. However, serum UN concentrations exhibited wide fluctuations, presumably due to a difference in renal handlings. The single-sample method using iodixanol was considered to be an expedient tool in both clinical and research settings, because the stress due to a multi-sample method was reduced.

The goals of this study were to determine if the glomerular filtration rate (GFR) in dogs could be estimated by plasma inulin clearance and/or infusion inulin clearance analyses without urine collection, and to compare these results with GFR values obtained by urinary inulin clearance analysis. The dogs included in this study were healthy 20 beagles. Inulin clearance values were obtained by urinary inulin clearance, infusion inulin clearance, and plasma inulin clearance techniques. Urinary inulin clearance was 4.09±0.52 ml min(-1) kg(-1) (body weight); infusion inulin clearance, 4.01±0.49 ml min(-1) kg(-1); and plasma inulin clearance, 4.14±0.66 ml min(-1) kg(-1). The urinary inulin clearance was strongly correlated with infusion inulin clearance and weakly correlated with plasma inulin clearance. The GFR for dogs can be estimated by infusion and plasma inulin clearance analyses by blood sampling alone, without urine collection., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

To develop a simple procedure for estimating glomerular filtration rate (GFR) in calves, a three-sample method using iodixanol was first compared to that using the standard agent inulin. Iodixanol and inulin were co-administered intravenously to calves at 40 mg I/kg and 40 mg/kg, respectively, and blood was collected 30, 60, 120, and 180 min later. Serum iodixanol and inulin concentrations were separately determined by high performance liquid chromatography and colorimetry. Serum urea nitrogen (UN) and creatinine concentrations were also measured. GFR estimated by iodixanol was consistent with that using inulin in clinically healthy calves. Based on GFR estimations in healthy calves and those renal-loaded with iodixanol, it was found that the serum creatinine concentrations became elevated when GFR decreased to 60% of the reference value. In contrast, serum UN concentrations fluctuated widely, presumably due to extra-renal factors. When GFR was estimated using the three-sample method and compared with the single-blood-sample method, 62/69 (90%) of samples tested were within the agreement plots. The results demonstrated that the single-blood-sample method using iodixanol may be useful in monitoring GFR in calves., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The evaluation of renal function in patients with cancer is necessary. Measuring the actual glomerular filtration rate of the patient is the gold standard. This is usually done using a measure of the renal clearance of a marker of glomerular filtration rate (inulin) or a radio-marker (EDTA Chrome 51, (51)Cr-EDTA). However, these measures are complex and very constraining for the patient and in terms of organization and equipment. It is possible to estimate renal function by calculation. There are in the literature many evaluation formulae available. However, it is essential to use a tool reliable enough to determine an appropriate estimate of renal function, and adjust the doses of treatment if necessary. The choice of the abreviated MDRD (aMDRD) formula is so far the recommended option in oncology.

Inulin is a polysaccharide with an extensive range of therapeutic uses such as a vehicle in drug delivery vehicle, as a diagnostic/analytical tool or as a dietary fibre with additional health benefits. In the main, much research has focussed on inulin as a drug delivery carrier for colon-targeted drug delivery. The justification for this is its potential to survive the stomach's acidic environment. This unique stability and strength is utilized in many ways to deliver drugs safely to colon, where they can be easily absorbed through the gut epithelium into the blood. Inulin based hydrodynamic research will be useful to discover the potential of inulin.

Objective: This pharmacokinetic study of S-1 was conducted in patients in whom glomerular filtration rate (GFR) was directly measured to explore the possibility of adjusting the S-1 dose on the basis of GFR in patients with normal or nearly normal renal function., Methods: S-1 was given to 12 patients twice daily for 28 consecutive days followed by 14 days of rest, repeated every 6 weeks. GFR was measured on the basis of inulin clearance (CLin) before the first day of treatment., Results: The area under the time-concentration curve (AUC) of 5-fluorouracil (5-FU) correlated with that of 5-chloro-2,4-dihydroxypyridine (CDHP, r = 0.750, p = 0.005). The AUC of CDHP correlated with the measured 24-hour creatinine clearance (CLcr) per subject (r = -0.620, p = 0.032), but not with the CLin (r = -0.356, p = 0.257). The AUC of 5-FU did not correlate with either the 24-hour CLcr per subject (r = -0.401, p = 0.187) or with the CLin (r = -0.300, p = 0.351)., Conclusion: Dosage adjustment based on the GFR does not reduce individual variations in 5-FU concentrations among patients with normal or nearly normal renal function who receive S-1., (Copyright © 2012 S. Karger AG, Basel.)

Rifampicin and caffeine are widely used drugs with reported protective effect against Alzheimer's disease (AD). However, the mechanism underlying this effect is incompletely understood. In this study, we have hypothesized that enhanced amyloid-β (Aβ) clearance from the brain across the blood-brain barrier (BBB) of wild-type mice treated with rifampicin or caffeine is caused by both drugs potential to upregulate low-density lipoprotein receptor related protein-1 (LRP1) and/or P-glycoprotein (P-gp) at the BBB. Expression studies of LRP1 and P-gp in brain endothelial cells and isolated mice brain microvessels following treatment with rifampicin or caffeine demonstrated both drugs as P-gp inducers, and only rifampicin as an LRP1 inducer. Also, brain efflux index (BEI%) studies conducted on C57BL/6 mice treated with either drug to study alterations in Aβ clearance demonstrated the BEI% of Aβ in rifampicin (82.4 ± 4.3%) and caffeine (80.4 ± 4.8%) treated mice were significantly higher than those of control mice (62.4 ± 6.1%, p < 0.01). LRP1 and P-gp inhibition studies confirmed the importance of both proteins to the clearance of Aβ, and that enhanced clearance following drugs treatment was caused by LRP1 and/or P-gp upregulation at the mouse BBB. Furthermore, our results provided evidence for the presence of a yet to be identified transporter/receptor that plays significant role in Aβ clearance and is upregulated by caffeine and rifampicin. In conclusion, our results demonstrated the upregulation of LRP1 and P-gp at the BBB by rifampicin and caffeine enhanced brain Aβ clearance, and this effect could explain, at least in part, the protective effect of rifampicin and caffeine against AD.

Objectives: The purpose of this study was to demonstrate the effects of the tight junction permeation enhancer, AT1002, on the nasal absorption of molecular weight markers and low bioavailable therapeutic agents co-administered with bioadhesive polymers or zonulin antagonist., Methods: The bioadhesive polymers, carrageenan and Na-CMC, were prepared with AT1002 to examine the permeation-enhancing effect of AT1002 on the nasal absorption of inulin, calcitonin and saquinavir after nasal administration to Sprague-Dawley rats. Blood samples were collected over a 6-hour period from a jugular cannula. In addition, we determined whether AT1002 exerts a permeation-enhancing effect via activation of PAR-2 specific binding to a putative receptor of zonulin. To examine this zonulin antagonist, AT1001, was administered 30 min prior to dosing with an AT1002/inulin solution and blood samples were collected over a 6-hour period., Key Findings: The bioadhesive polymers did not directly increase the absorption of inulin, calcitonin and saquinavir, but promoted the permeation-enhancing effect of AT1002 when delivered nasally, thereby significantly increasing the absorption of each drug. Pre-treatment with AT1001 antagonized the zonulin receptor and significantly minimized the permeation-enhancing effect of AT1002., Conclusion: These findings will assist in understanding the permeation-enhancing capability of and the receptor binding of AT1002. Further, combining AT1002 with carrageenan supports the development of the mucosal delivery of therapeutic agents that have low bioavailability even with bioadhesive agents., (© 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.)

The aim of this study was to evaluate the effect of Gd-chelate on renal function, iron parameters and oxidative stress in rats with CRF and a possible protective effect of the antioxidant N-Acetylcysteine (NAC). Male Wistar rats were submitted to 5/6 nephrectomy (Nx) to induced CRF. An ionic-cyclic Gd (Gadoterate Meglumine) was administrated (1.5 mM/KgBW, intravenously) 21 days after Nx. Clearance studies were performed in 4 groups of anesthetized animals 48 hours following Gd- chelate administration: 1--Nx (n = 7); 2--Nx+NAC (n = 6); 3--Nx+Gd (n = 7); 4--Nx+NAC+Gd (4.8 g/L in drinking water), initiated 2 days before Gd-chelate administration and maintained during 4 days (n = 6). This group was compared with a control. We measured glomerular filtration rate, GFR (inulin clearance, ml/min/kg BW), proteinuria (mg/24 hs), serum iron (µg/dL); serum ferritin (ng/mL); transferrin saturation (%), TIBC (µg/dL) and TBARS (nmles/ml). Normal rats treated with the same dose of Gd-chelate presented similar GFR and proteinuria when compared with normal controls, indicating that at this dose Gd-chelate is not nephrotoxic to normal rats. Gd-chelate administration to Nx-rats results in a decrease of GFR and increased proteinuria associated with a decrease in TIBC, elevation of ferritin serum levels, transferrin oversaturation and plasmatic TBARS compared with Nx-rats. The prophylactic treatment with NAC reversed the decrease in GFR and the increase in proteinuria and all alterations in iron parameters and TBARS induced by Gd-chelate. NAC administration to Nx rat did not modify the inulin clearance and iron kinetics, indicating that the ameliorating effect of NAC was specific to Gd-chelate. These results suggest that NAC can prevent Gd-chelate nephrotoxicity in patients with chronic renal failure.

Inulin, a natural oligomer of fructose, is classified as a food component. It can be found in some plants and vegetables, i.e. chicory, Jerusalem artichoke, elecampane, and dandelion. Following ingestion, inulin reaches the lower part of the gastrointestinal tract where it is fermented increasing the bifidobacterial population of the colon. The growth of bifidobacteria regulates cholesterol concentration and absorption of minerals. Inulin added to food may prevent the spread of civilization diseases, like diabetes and obesity.

Although poly(ethylene glycol) and polysaccharide have been widely used as pharmaceutical carriers for decades, they both have some disadvantages. In order to overcome these shortcomings, this study was conducted to prepare and assess a novel polymeric carrier, PEGylated inulin. Three conjugates, with an average of 1.4 PEG (20 kDa), 3.1 PEG (20 kDa) and 5.5 PEG (5 kDa) residues per single inulin (5 kDa) molecule, respectively, were prepared through the reaction of hydroxyl-activated inulin with amino-terminated methoxy-PEGs. Their pharmacokinetic properties were evaluated in rats following i.v. and s.c. administration. These conjugates, following i.v. administration, displayed multi-compartmental pharmacokinetics with the mean retention times being 9.8, 80 and 90 h, respectively. When given subcutaneously, they were well absorbed with the absolute bioavailability ranging from 66% to 79% and the mean retention times being 35, 155 and 179 h, respectively. Both the small size and the long circulation lifetime suggest their potential application as a pharmaceutical carrier to enhance the delivery of various agents to their targets by the enhanced permeability and retention (EPR) effect.

Background: Very few studies have been published that compare plasma clearance of iohexol (Cio) with renal clearance of inulin (Cin)., Study Design: Diagnostic test study., Setting & Participants: 60 children aged 11.6 ± 4.5 years with different kidney disorders were investigated., Index Test: Plasma Cio calculated from the slope and a single point., Reference Test: Renal Cin with continuous infusion during water diuresis. Results were compared with the correlation coefficients, bias and precision, accuracy percentage, root mean square error, and intraclass correlation., Other Measurements: Measured creatinine clearance and estimated glomerular filtration rate based on serum creatinine level and height., Results: Mean Cin was 70.7 ± 41.3 (SD) mL/min/1.73 m². Mean differences between Cio and Cin were 2.65 and 2.00 mL/min/1.73 m² for the slope and single-point methods, respectively. Precision was ±16 mL/min/1.73 m² and intraclass correlation was 0.92 in both methods. Proportions of Cio within 30% of Cin were 83.3% and 86.7% for the slope and single-point methods, respectively., Limitations: A limited number of patients; no adults were studied., Conclusions: Plasma Cio shows good agreement with renal Cin., (Copyright © 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Previously, we showed that supplementation of diets with short-chain inulin (P95), long-chain inulin (HP), and a 50:50 mixture of both (Synergy 1) improved body iron status and altered expression of the genes involved in iron homeostasis and inflammation in young pigs. However, the effects of these 3 types of inulin on intestinal bacteria remain unknown. Applying terminal restriction fragment length polymorphism analysis, we determined the abundances of luminal and adherent bacterial populations from 6 segments of the small and large intestines of pigs (n = 4 for each group) fed an iron-deficient basal diet (BD) or the BD supplemented with 4% of P95, Synergy 1, or HP for 5 wk. Compared with BD, all 3 types of inulin enhanced (P < 0.05) the abundance of beneficial bifidobacteria and lactobacilli in the microbiota adherent to intestinal mucus of various gut segments of pigs. These changes were seen as proximal as in the jejunum with P95 but did not appear until the distal ileum or cecum with HP. Similar effects of inulin on bacterial populations in the lumen contents were found. Meanwhile, all 3 types of inulin suppressed the less desirable bacteria Clostridium spp. and members of the Enterobacteriaceae in the lumen and mucosa of various gut segments. Our findings suggest that the ability of dietary inulin to alter intestinal bacterial populations may partially account for its iron bioavailability-promoting effect and possibly other health benefits.

Background: Accurate evaluation of the glomerular filtration rate (GFR) in patients awaiting liver transplantation is important because they have a greater risk of impaired renal function. A major percentage of these patients have alcoholic cirrhosis, and the accuracy of bedside used GFR estimates have not been specifically evaluated in this group. The aim of this study was to evaluate the validity of the simplified Modification of Diet in Renal Diseases (MDRD) and Cockcroft and Gault (CG) formulas in patients with decompensated alcoholic cirrhosis in comparison to inulin clearance as the reference method., Methods: GFR estimated by the simplified MDRD and CG formulas were retrospectively compared to the true GFR measured by inulin clearance in a single-centre cohort of 148 patients with decompensated alcoholic cirrhosis., Results: Mean ± standard deviation of age, body mass index, inulin clearance and MDRD and CG estimates were 54.4 ± 6.9 years, 26.5 ± 4.7 kg/m(2), 76.9 ± 28.0 mL/min per 1.73 m(2), 99.4 ± 34.0 mL/min per 1.73 m(2) and 98.7 ± 32.0 mL/min per 1.73 m(2), respectively; 70% of the patients had a GFR, measured by inulin clearance, below 90 mL/min per 1.73 m(2). The difference between estimated GFR and true GFR were 23 ± 23 mL/min per 1.73 m(2) for MDRD and 22 ± 20 mL/min per 1.73 m(2) for Cockcroft and Gault., Conclusions: The simplified MDRD and CG formulas largely overestimated GFR in patients with decompensated alcoholic cirrhosis. Results of such bedside formulas should be interpreted with caution in these patients.

TMC240 is a very poorly soluble and poorly permeating HIV protease inhibitor. In order to enhance its oral bioavailability, a fast dissolving inulin-based solid dispersion tablet was developed. During the dissolution test in water (0.5% or 1.0% SLS), this tablet released at least 80% of TMC240 within 30min, while a tablet with the same composition, but manufactured as physical mixture, released only 6% after 2h. In a subsequent single-dose study in dogs (200mg of TMC240), plasma concentrations of TMC240 remained below the lower limit of quantification (<1.00ng/mL) in all animals (n=3 per tested formulation), except in one dog receiving the inulin solid dispersion tablet (C(max)=1.8ng/mL, AUC(0-7 h)=3.0ngh/mL). In the latter treatment group, ritonavir co-administration (10mg/kg b.i.d.) increased TMC240 exposure more than 30-fold (mean AUC(0-7 h)=108ngh/mL; F(rel)=3588%). Exposure was also 16-fold higher than after TMC240 administration as PEG400 suspension in the presence of ritonavir (AUC(0-7 h)=6.7ngh/mL). The current data demonstrate that a solid dispersion of TMC240 in an inulin matrix allows considerable improvement in the release of poorly water-soluble TMC240, both in vitro in the presence of a surfactant and in vivo upon oral administration., (Copyright (c) 2009 Elsevier B.V. All rights reserved.)

Background: A proper measurement of renal function is important for diagnosis and stratification of kidney disease. Several methods have been used to predict glomerular filtration rate, however the results have been variable depending on the population studied. We aimed to compare the performances of 4 glomerular filtration rate tests with inulin clearance in patients with chronic renal insufficiency and in healthy subjects., Methods: Inulin clearances performed in 51 individuals with stable renal function were selected. For each of them, we computed 4 estimates: the 24-hour creatinine clearance, technetium (99mTc-DTPA) clearance, Cockcroft-Gault and Levey formulas. Their respective performance was assessed by correlation (Pearson's correlation coefficient) and agreement (Bland and Altman method)., Results: Each glomerular filtration rate test closely correlated with inulin clearance. Nevertheless, all GFR tests displayed considerable lack of agreement with lower limits ranging from 15 to 42 ml / min, for comparison with inulin-technetium and inulin with Levey formula, respectively and upper limits of agreement that could range from 20 to 56 ml / min, for comparison with inulin-technetium and Inulin with Levey formula,respectively., Conclusion: The measurement of glomerular filtration rate determined via different methods shows a wide range of variation when compared with inulin clearance, which should be considered in daily clinical practice during the evaluation of renal function.

Background/aims: Patients treated with peroxisome proliferator-activated receptor analogs (PPAR) alpha or alpha/gamma may develop a transient and reversible increase in serum creatinine, the mechanism of which remains obscure. This study evaluates whether treatment with either PPAR-alpha or -alpha/gamma analogs, fenofibrate or tesaglitazar, may cause deterioration in renal hemodynamics or exert direct tubular or glomerular nephrotoxic effects in rats., Methods: Male Sprague-Dawley rats (300-320 g) were treated per os with fenofibrate (300 mg/kg/day), tesaglitazar (1.2 mg/kg/day) or vehicle, for 14 days. Glomerular filtration rate (GFR) and renal blood flow (RBF) were measured by inulin clearance and ultrasonic flowmetry, and cumulative excretion of sodium and creatinine were assessed. Biomarkers of glomerular and tubular injury were measured, including urinary albumin excretion and renal mRNA levels of kidney injury molecule 1 (Kim-1), lipocalin 2 (Lcn2), and osteopontin (Spp1)., Results: Fenofibrate and tesaglitazar improved the lipid profile, but caused no detectable decrease in GFR or RBF compared with vehicle-treated rats. Furthermore, the cumulative excretions of sodium and creatinine were not altered by the drugs. Finally, there was no significant difference between drug- and vehicle-treated groups in urinary albumin excretion or in the expression of renal injury biomarkers., Conclusions: In the rat, no direct nephrotoxic effect or deterioration in renal hemodynamics and function were observed following treatment with fenofibrate or tesaglitazar., (2010 S. Karger AG, Basel.)

Prebiotics may enhance iron bioavailability by increasing iron absorption in the colon. Anemic pigs fitted with cecal cannulas were fed a low-iron diet with or without 4% inulin. Over 7 days, pigs were administered 1 mg of (54)Fe in the morning feed followed by cannula infusion of 0.5 mg of (58)Fe to measure total and colonic iron absorption, respectively. Whole blood was drawn prior to the initial dosing and 14 days thereafter for hemoglobin concentration and stable isotope ratio analyses. The prebiotic role of inulin was confirmed by increases in lactobacilli and bifidobacteria with reductions in clostridia using terminal restriction fragment length polymorphism (TRFLP). Total iron absorption was 23.2 +/- 2.7 and 20.7 +/- 3.5% (mean +/- SEM; p > 0.05), while colonic iron absorption was 0.4 +/- 0.1 and 1.0 +/- 0.2% (mean +/- SEM; p > 0.05) in inulin-fed and control pigs, respectively. These results show that the colon does not make a significant contribution to total iron absorption in iron-deficient pigs and that inulin does not affect iron absorption in the colon.

Since the distribution of substances between various cerebrospinal fluid (CSF) compartments is poorly understood, we studied (3)H-inulin distribution, over time, after its injection into cisterna magna (CM) or lateral ventricle (LV) or cisterna corporis callosi (CCC) in dogs. After the injection into CM (3)H-inulin was well distributed to cisterna basalis (CB), lumbar (LSS) and cortical (CSS) subarachnoid spaces and less distributed to LV. When injected in LV (3)H-inulin was well distributed to all CSF compartments. However, after injection into CCC (3)H-inulin was mostly localized in CCC and adjacent CSS, while its concentrations were much lower in CM and CB and very low in LSS and LV. Concentrations of (3)H-inulin in venous plasma of superior sagittal sinus and arterial plasma were very low and did not differ significantly, while its concentration in urine was very high. In (3)H-inulin distribution it seems that two simultaneous processes are relevant: a) the pulsation of CSF with to-and-fro displacement of CSF and its mixing, carrying (3)H-inulin in all directions, and b) the passage of (3)H-inulin from CSF into nervous parenchyma and its rapid distribution to a huge surface area of capillaries by vessels pulsations. (3)H-inulin then slowly diffuses across capillary walls into the bloodstream to be eliminated in the urine.