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OBJECTIVE: Widespread hypovitaminosis D and an increased incidence of metabolic syndrome (MetS) represent significant problems of contemporary medicine but link between them remain unresolved. We aimed to define relationship between vitamin D serum concentration and exponents of MetS. PATIENTS AND METHODS: The studies were conducted on 70 individuals (51 with and 19 without MetS). Concentrations of 25(OH)D (25-hydroxyergocalciferol and 25-hydroxycholecalciferol), calcium, cholesterol, HDL, cholesterol LDL, triglycerides, fasting glucose, blood pressure and anthropometric parameters were measured. RESULTS: Median concentration of vitamin D in the research population amounted to 41.46 nmol/L. Concentration of 25(OH)D in MetS group was lower than in remainder participants (38.45 nmol/L vs. 58.50 nmol/L, p = 0.0104). An inverse correlation was demonstrated between 25(OH)D level on one hand and body weight, waist and hips circumference, adipose body weight, Body Mass Index, Waist to Height Ratio (WHtR), glycaemia and number of MetS components on the other in persons free of MetS. No such relationships could be documented in MetS group. In the entire population values of Waist to Hip Ratio (WHpR) and WHtR indices manifested correlation with hyperglycaemia, hypertriglyceridaemia, low HDL concentrations. CONCLUSIONS: In persons without MetS a relationship was detected between vitamin D concentration and exponents of metabolic syndrome, although further studies on this problem are required. [ABSTRACT FROM AUTHOR]

The presented work involves obtaining and characterising a two-enzymatic one-pot bioreactor, including encapsulated (co-immobilised) glucose oxidase and catalase. The enzymatic capsules were applied to produce unsweet, lactose-free milk during low-temperature catalysis. Furthermore, operational conditions, like pH and aeration, were selected in the paper, which sorts out discrepancies in literature reports. All experiments were carried out at 12 °C, corresponding to milk storage and transportation temperature. Preliminary studies (for reasons of analytical accuracy) were carried out in a buffer (pH, concentration of sugars mimicking conditions in the lactose-free milk, the initial glucose concentration 27.5 g/L) verified by processes carried out in milk in the final stage of the study. The presented results showed the need for regulating pH and the aeration of the reaction mixture in the continuous mode during the process. The procedure of co-immobilisation was performed in an alginate matrix with the cross-linking of glutaraldehyde or carbodiimide while carbodiimide showed better enzymes retention inside alginate capsules. Co-encapsulated enzymes could be used for nine cycles, preserving finally about 40% of the initial activity.

Introduction: The aim of our study was to determine the relationship between neuropeptide B (NPB), neuropeptide W (NPW), nutritional and antioxidant status and selected fat- and bone-derived factors in type 1 diabetes mellitus (T1DM) treated using pens (T1DM pen group) or insulin pumps (T1DM pump group) in order to investigate the potential role of NPB and NPW in the clinical outcomes of T1DM., Material and Methods: Fifty-eight patients with T1DM and twenty-five healthy controls (CONTR) participated in the study. Assessments of NPB, NPW, total antioxidant status (TAS), leptin, adiponectin, osteocalcin, and free soluble receptor activator for nuclear factor κB (free sRANKL) were conducted., Results: NPB, NPW, leptin, and TAS were lower (by 33%, p < 0.013; 34%, p < 0.008; 290%, p < 0.00004; 21%, p < 0.05; respectively), while adiponectin was by 51% higher ( p < 0.006) in T1DM vs. CONTR, while osteocalcin and free sRANKL levels were similar in both groups. NPW was lower in the T1DM pen group both vs. the T1DM pump group (36% lower, p < 0.0009) and vs. the CONTR group (35% lower, p < 0.002). In the T1DM pen group, but not in the T1DM pump group or the CONTR group, the Cole index and TAS levels explain (besides NPB) the variation in NPW values. ROC curves showed that serum levels of leptin, adiponectin, NPB and NPW (but not osteocalcin or free sRANKL) were predictive indicators for T1DM., Conclusions: Measurements of NPB and NPW, besides leptin and adiponectin, are worth considering in the detailed prognosis of nutritional status in T1DM, primarily in the T1DM pen-treated population., Competing Interests: The authors declare no conflict of interest.

Introduction: The aim of the study was to assess the correlation between the levels of neuropeptide B (NPB), neuropeptide W (NPW), vaspin (VAS), and the total antioxidant status (TAS) in the blood, as well as nutritional status of patients with anorexia nervosa (AN)., Materials and Methods: The study covered a cohort of 76 female teenagers, including 46 females with extreme AN and 30 healthy peers (CONTR) aged 12-17., Results: AN persons were characterized by higher (in comparison to CONTR) NPB and VAS concentrations and lower values of TAS levels, body weight, and anthropometric values. Positive correlations between NPB and VAS levels were noted in the AN group (R=0.33; p<0.001) as well as between concentrations of NPW and VAS in the same group (R=0.49; p<0.001). Furthermore, positive correlations existed between NPB and NPW concentrations across the whole studied population (AN+CONTR; R=0.75; p<0.000001), AN (R=0.73; p<0.000001) and CONTR (R=0.90; p<0.0005)., Conclusions: In detailed diagnostics of AN it is worth considering testing NPB and VAS levels.

Introduction: The aim of the study was to evaluate the correlation between the nutritional status of patients with anorexia nervosa (AN) and levels of vaspin (VASP), neuropeptide B (NPB), neuropeptide W (NPW) and total antioxidant status (TAS)., Material and Methods: Ninety serum samples collected from 30 teenage female patients during the acute stage of AN and 30 healthy persons (CONTR) were subjected to biochemical analysis; patients with AN were examined at the beginning of the study (AN-I) and after hospitalization (AN-II), as a result of which partial stabilization of anthropometric measurements was achieved (an increase of body mass index (BMI) by 3.5 kg/m 2 )., Results: Vaspin levels dropped at the end of the hospitalization (compared to AN-I, p < 0.05), achieving values comparable to the CONTR; moreover there was a positive correlation between VASP level and the achieved body weight in AN-II ( p < 0.05). Positive correlations were also noted with regard to VASP vs. NPB in AN-I ( p < 0.02) (and AN-II, p < 0.013), as well as in the case of VASP vs. NPW in the same groups ( p < 0.02 and p < 0.015, respectively). NPB concentration was higher in AN-I ( p < 0.05) and AN-II ( p < 0.018) than in CONTR, whereas there were no differences ( p > 0.05) with regard to levels of VASP, NPW, or TAS., Conclusions: The high level of NPB despite treatment and normalization of VASP level may suggest that there are chronic neuroendocrine disorders at play in anorexia nervosa., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2018 Termedia & Banach.)

Introduction: Omentin and vaspin are adipokines manifesting a potentially protective action against obesity-associated metabolic disturbances., Aim: Evaluation of relationship between serum concentrations of omentin and vaspin on one hand and indices of insulin resistance and anthropometric parameters in obese individuals on the other., Material and Methods: The studies were conducted on 64 individuals. The investigated group (37 obese patients) included the subgroup with normal glucose tolerance (NGT) and with abnormal glucose tolerance (AGT). The control group (n=27) included healthy individuals with normal body weight. In all participants anthropometric analyses and biochemical tests, including estimation of omentin and vaspin concentrations were performed, and insulin resistance by HOMA-IR was evaluated., Results: Concentrations of examined adipokines manifested no significant differences between the examined groups. Median values of the index defining ratio between studied adipokine and degree of insulin resistance, i.e. omentin/HOMA-IR, proved to be different in the investigated and the control group while no such difference could be noted in cases of vaspin/HOMA-IR indices. In the studied population a negative relationship was detected between serum concentration of omentin and systolic blood pressure (p<0.04). Values of omentin/HOMA-IR index manifested a correlation with values of most anthropometric parameters (p<0.0001), blood pressure (p<0.0001) concentrations of TG (p<000.1) and HDL (p<0.0001), ISI basal (p<0.00001), ISI gly (p<0.0001), Quicki (p<0.00001) and fasting insulinaemia (p<0.00001). In the case of vaspin/HOMA-IR index only its positive relationship with HDL concentration was noted (p<0.05)., Conclusion: In context of date of correlation, multiple regression and values of area of under receiver operating characteristics curve omentin, as compared to vaspin, seems to provide a better predictor of insulin resistance in obese individuals., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Prednisolone and other glucocorticosteroids are used by some peritoneal dialysis patients because of underlying diseases such as peritonitis. Although corticosteroids are potent inhibitors of various processes during inflammation, their influence on the transport properties of peritoneum is little known. Our study investigated the influence of prednisolone (0.001 g/dL) on glucose (1.8 g/dL) and uric acid (0.02 g/dL) transfer across isolated parietal peritoneum taken from the anterior abdominal wall of white Hyplus 59 rabbits and placed inside a modified Ussing-type chamber. Values for transfer from the interstitial (I) to the mesothelial (M) side of membrane (I-->M) and in the opposite direction (M-->I) were calculated using the mathematical model of mass transport and are expressed as a coefficient of diffusive permeability [P (in centimeters per second)]. Four separate series of experiments were done. In the first and second series, we respectively examined glucose transport under control conditions (for 120 minutes) and then before (15-60 minutes) and after (75-120 minutes) introduction of prednisolone on the M side of the membrane. In the third and fourth series, similar studies of uric acid transfer were done. In the control (first and third) series, the stability of bidirectional transport for solute of interest was observed. The values of P +/- standard error of the mean (all x0.0001) for I-->M and M-->I transfer of glucose were, respectively, 2.489 +/- 0.329 cm/s and 2.259 +/- 0.493 cm/s. In the case of uric acid, the transport values were lower and amounted 1.936 +/- 0.324 cm/s and 1.895 +/- 0.596 cm/s for I-->M and M-->I respectively. Application of prednisolone on the M side of membrane lowered bidirectional transfer of glucose across peritoneal membrane by a mean of 73% (p < 0.02) and transport of uric acid by a mean of 19% (p < 0.003). These results show that, in vitro, prednisolone lowers glucose and uric acid transport across the peritoneal membrane, modifying the transfer dynamics of glucose to a greater extent. These observations may have clinical importance, especially in patients with disorders of peritoneal permeability, diabetes, and hyperuricemia.

Glucose or its polymer is usually added to dialysis solution for the development of sufficient ultrafiltration during peritoneal dialysis. The aim of the present study was to determine the influence of glucose and icodextrin on the transport of gentamicin and insulin from the mesothelial to the interstitial side of the peritoneal membrane. Transfer values are expressed as a coefficient of diffusive permeability, P, in centimeters per second. Each of the molecules was tested in 3 series of experiments using rabbit parietal peritoneum, a modified Ussing chamber, and a mathematical model of mass transport. First, transperitoneal transfers of gentamicin (0.040 g/dL) and insulin (0.1 g/dL) were analyzed in control conditions for 120 minutes. Then, transport parameters for gentamicin and insulin were separately determined before (15-60 minutes) and after (75-120 minutes or 75-130 minutes) the application of glucose (1.8 g/dL) or icodextrin (2 g/ dL) on the mesothelial side of the peritoneal membrane. Insulin transport was observed to be stable in the control series. Gentamicin transfer was not stable; its passage declined by 52% (p < 0.01) in the control series. The mean transfer parameters were 7.41 +/- 1.40 cm/s (x0.0001) over 15-30 minutes and 3.21 +/- 0.54 cm/s (x0.0001) over 75-130 minutes. Gentamicin transfer declined less in the series with glucose or icodextrin, by 21% (p < 0.04) and 30% (p < 0.05) respectively, than in the control series. For insulin, the mean P (+ standard error of the mean) was 0.15 +/- 0.02 cm/s (x0.0001) at the first hour of transfer and 0.14 - 0.02 cm/s (x0.0001) at the second. Glucose induced a nonsignificant intensification of insulin transport. Icodextrin increased insulin passage by 107% (p < 0.03). Osmotic and oncotic factors (glucose and icodextrin) both stabilize the transfer of gentamicin across the peritoneal membrane in vitro. Glucose polymer intensifies insulin transport from the mesothelial to the interstitial side of the peritoneum. Similar modifications might be observed in vivo during peritoneal dialysis or continuous intraperitoneal administration of insulin, influencing the efficiency of those treatments.

Our study investigated uric acid transport across isolated parietal peritoneum taken from the anterior abdominal wall of white New Zealand rabbits and placed inside a modified Ussing-type chamber. Values for transfer from the mesothelial to the interstitial side of membrane (M --> I) were calculated using the mathematical model of mass transport and are expressed as a coefficient of diffusive permeability [P (in centimeters per second)]. Four separate series of experiments were done. In the first series, we examined uric acid transfer in control conditions (for 120 minutes). In the second and third series, P was calculated before (15 - 60 minutes) and after introduction of p-cresol (0.005 g/dL) or sodium hyaluronan (0.04 g/dL) on the M side of the membrane. In the fourth series, transfer parameters were measured before (15 - 75 minutes) and after (90 - 150 minutes) application of sodium deoxycholate (0.104 g/dL). The dynamics of transperitoneal transport of uric acid were stable. The values of P +/- standard error of the mean (x0.0001) were 1.936 +/- 0.324 cm/s and 2.078 +/- 0.186 cm/s. Application of p-cresol on the M side of membrane lowered uric acid transport by 10%. Application of sodium hyaluronan produced no change, but application of sodium deoxycholate increased the transfer of uric acid by 155%. These observations may have clinical importance.

Charge factors and reactive carbonyl solutes may change peritoneal structure and the transport properties of peritoneum. The aim of the present study to analyze the influence of polycationic protamine and glucose degradation products on the diffusive permeability (P) of peritoneal membrane for urea in vitro. Values for diffusion from the interstitial (1) to the mesothelial (M) side of the membrane and in opposite direction are expressed as coefficients of diffusive permeability. Four separate series of experiments were conducted. In the first experiment, transperitoneal transfer of urea (20 mg/dL) in control conditions over 120 minutes was analyzed. In the subsequent three experiments, transport parameters were analyzed before (15 - 60 minutes) and after (75 - 120 minutes) the addition of chemical factors (protamine sulfate 5 mg/dL, glyoxal 10 mg/dL, methylglyoxal 1 mg/dL) on the mesothelial side of the peritoneal membrane. Stability of urea transport was observed in the control series (120 minutes). The mean diffusive permeability coefficients (P = standard error of the mean) were 2.293 +/- 0.211 cm/s and 2.621 +/- 0.457 cm/s (x0.0001) for I --> M and M --> I transfer respectively. Protamine and methylglyoxal did not alter transport, but glyoxal lowered urea M --> I transport by 12% (p < 0.01), with a statistically nonsignificant reduction in opposite direction. Similar modifications are observed in vivo during peritoneal dialysis and may influence the efficiency of renal replacement therapy.

This paper specifies the peritoneal dialysis problems as a method of renal replacement therapy in a historical perspective. It pointed out to the dynamic development of peritoneal dialysis in the nineties and distinct slump of the presented treatment form at the turn of XXth and XXIst century, despite substantial progress in the dialysis techniques, effectiveness and biocompatibility of the therapy as well as a detailed evaluation of peritoneal function in vivo and in vitro. It showed descriptions and outline of the peritoneal cavity dating from ancient times, 19th-century animal experiments determining essential laws of peritoneal absorption and removal molecules, as well as the first peritoneal dialysis of a man which took place at the beginning of the 20th-century. The technical problems and peritonitis were the fundamental limitations of this therapy employment in this phase of dialysis development. The application of Tenckhoffs catheter and the technique specified as continuous ambulatory peritoneal dialysis was the invention and at the same time, the turning point which decided about the considerable progress of the described method of dialysis in the nineties. In this period, the analyses concerning failures of the peritoneal transport functions and protection of peritoneum during its long-term use as a dialysis membrane dominated. These studies referred to not absolutely biocompatibility factors of the environment of the peritoneal cavity during peritoneal dialysis. Thence, proposed future directions of analyses include researches concerning components of dialysis solution to assure long-term preservation of peritoneal transport functions and its secretory properties. It is not excluded that experiments of applying the newest achievements of regenerative medicine, in the scope of genetic modification and implantation of mesothelial cells will be continued.

Production of corticosteroids from the adrenal gland is a multistep process in which corticosterone is enzymatically processed from its precursor cholesterol. The main hormone regulating the production of corticosterone is the proopiomelanocortin (POMC)-derived adrenocorticotropic hormone (ACTH). Adrenals of POMC-deficient (POMC(-/-)) mice do not produce corticosterone either at basal levels or in response to acute stimulation with ACTH. However, pharmacological amounts of ACTH delivered continuously elicit corticosterone production over time. To define the relative effects of ACTH on individual factors involved in corticosterone production, parameters of adrenal cholesterol metabolism and steroidogenesis were examined in POMC(-/-) mice compared with wild-type and ACTH-treated mutant mice. POMC(-/-) adrenals lack cholesterol esters (CE); adrenal CE is restored with ACTH treatment. However, discontinuation of ACTH treatment stops corticosterone production despite the presence of adrenal CE. Failure of corticosterone production by POMC(-/-) adrenals occurs despite the constitutive presence of transcripts of genes required for cholesterol metabolism and steroidogenesis. Levels of key proteins involved in selective cholesterol uptake and steroidogenesis were attenuated; ACTH treatment increased these protein levels, most significantly those of the receptor responsible for selective uptake of CE, scavenger receptor class B, type I (SR-BI). Our studies reveal that failure of corticosterone production of POMC(-/-) adrenal glands and its pharmacological reconstitution by ACTH are not mediated by any one individual protein, but rather as an integrated effect on multiple factors from import of the substrate cholesterol to its conversion to corticosterone.

Hyaluronan (HA), an essential component of peritoneal extracellular matrix, participates in restoring peritoneal integrity and remodeling the peritoneum changed by prolonged peritoneal dialysis and repeated peritonitis episodes. The aim of the present study was to compare urea, creatinine, and uric acid transport across the peritoneal membrane in control conditions and after HA application. Experiments were undertaken using rabbit parietal peritoneum and a modified Ussing-type chamber. Values of the transfer directed from the interstitial to the mesothelial side of the membrane (I --> M) and in the opposite direction (M --> I) were expressed as coefficients of diffusive permeability P. Transperitoneal transport in control conditions (for 120 minutes) and transfer parameters before (15 - 60 minutes) and after HA application (2000 kDa, 0.04 g/dL, 75-120 minutes) were examined. In the control series, stability of bidirectional transport for urea (0.02 g/dL), creatinine (0.1 g/dL), and uric acid (0.02 g/dL) was observed. The values of P +/- standard error of the mean for I --> M and M --> I transfers were respectively 2.293 +/- 0.211 and 2.621 +/- 0.457 for urea, 1.522 +/- 0.102 and 1.865 +/- 0.244 for creatinine, and 1.936 +/- 0.324 and 2.078 +/- 0.186 for uric acid [all x 10(-4) cm/s]. Application of HA reduced bi-directional urea transport by a mean of 12%, but did not change the P for creatinine and uric acid. These results show that in vitro HA modifies the dynamics of transport for certain small solutes.

The aim of the in vitro studies was to examine the effect of sodium deoxycholate, glucose, and methylglyoxal on icodextrin peritoneal transfer. The rabbit peritoneum in a modified Ussing chamber was an experimental model. Transport and morphometric analyses were performed. In the first of them, the icodextrin (7.5 g/dL) diffusion from the mesothelial to the interstitial side of the membrane, expressed as a diffusive permeability coefficient (P), was evaluated in the control stage, after chemical modification of the membrane using sodium deoxycholate (104 mg/dL), after the addition of glucose (1.8 g/dL) and methylglyoxal (1 mg/dL), in the separate experimental series. In the second morphometric studies, the thickness and transverse cross-section surface area of native tissue, in 75 min of experiment and after application of sodium deoxycholate, were investigated. In the control conditions, the rate of glucose polymer passage remained constant. A mean value of P +/- SD was 0.194 +/- 0.126 (x10(-4), cm/s) during 120 min of the study. The transfer of icodextrin was enhanced by 224% after 3 min of incubation of the peritoneum with sodium deoxycholate. The introduction of glucose into the circulating medium with icodextrin caused the increase of P values for glucose polymer by 94% during 60 min. In the same conditions, the usage of methylglyoxal did not change transport parameters. Both thickness and transverse cross-section surface area of the native tissue in 75 min of the study did not differ. It was 4.87 microm and 12.50 x 10(2) microm(2) for the mesothelial layer, and 63.83 microm and 208.10 x 10(2) microm(2) for the whole peritoneal membrane. The application of sodium deoxycholate caused the decrease of mesothelium thickness by 20% but the increase of thickness and transverse cross-section surface area of the peritoneum by 37% in comparison with 75 min of experiment. In conclusion, sodium deoxycholate and glucose, but not methylglyoxal, intensify peritoneal transport of icodextrin in vitro. These modifications are probably connected with the exfoliation of the mesothelium and looseness of the interstitium caused by sodium deoxycholate as well as the physical and metabolic influence of glucose on the peritoneum.

This paper is a review of the literature describing the complexity of the peritoneal membrane structure and functions, mechanisms of the peritoneum failure as a dialyzing membrane and strategies for its protection during prolonged peritoneal dialysis.

We undertook in vitro experiments to examine the importance of mesothelium and interstitium in icodextrin (7.5 g/dL) transport and the change in that transport caused by gentamicin and methylglyoxal. Rabbit peritoneum, a modified Ussing chamber and a mathematical model of mass transport were used. Transfer from the interstitial to mesothelial side of the membrane (I-->M) and in the opposite direction (M-->I), expressed as a diffusive permeability coefficient P, was determined in control series, after chemical modification of the peritoneum by sodium deoxycholate, and after introduction of gentamicin and methylglyoxal. We also investigated the thickness of native tissue 75 minutes into the study and after use of sodium deoxycholate. In the control series, icodextrin I-->M transport increased by 50%, but M-->I transport remained stable [15-60 min vs. 75-120 min. I-->M P, 0.32 +/- 0.04 x 10(-4) cm x s(-1) (standard error of the mean); M-->I P, 0.19 +/- 0.03 x 10(-4) cm x s(-1)]. After application of sodium deoxycholate, I-->M transport was observed to increase by 21% and M-->I by 192% as compared with the 2nd hour of the control series. Gentamicin caused a rise of M-->I transport by 21% without a change of I-->M. We observed no difference in p values (I-->M and M-->I) after application of methylglyoxal. Mean thickness before and 75 minutes into the study was 4.96 +/- 0.28 microm for mesothelium and 62.09 +/- 2.40 microm for the whole peritoneum. Sodium deoxycholate reduced the mesothelium thickness by 20% and increased the peritoneum thickness by 37%. The present study confirms that, in vitro, icodextrin I-->M peritoneal transport changes with time, but M-->I is constant. Asymmetry of glucose polymer diffusion is observed. I-->M predominates over M-->I. Chemical modification of the peritoneum by sodium deoxycholate (I-->M and M-->I directions) and by gentamicin (M-->I direction only), but not by methylglyoxal, intensifies icodextrin transport. Sodium deoxycholate causes exfoliation of the mesothelium and looseness of the interstitium.

In patients with end-stage renal disease on peritoneal dialysis, the peritoneum is effectively utilized as an endogenous semipermeable membrane. Chemical agents may alter the structure of the peritoneum and induce changes in its transfer properties. The purpose of our in vitro study was to compare the influence of sodium hyaluronan (a cytoprotective glycosaminoglycan, 2000 kDa, 40 mg/dL) and sodium deoxycholate (an intense oxidative stress factor, 414 Da, 104 mg/dL) on the transfer of insulin (5.8 kDa, 100 mg/dL) and albumin (68 kDa, 1000 mg/dL) through isolated rabbit parietal peritoneum. We used a mathematical model to calculate the transport rate of solutes from the interstitial to the mesothelial side of peritoneal membrane (I-->M) and in the opposite direction (M-->I) in three separate series of experiments: Control conditions without chemical agents Before (15-60 minutes) and after (75-120 minutes) introduction of sodium hyaluronan into the experimental system Before (15 -75 minutes) and after (90-150 minutes) introduction of sodium deoxycholate into the experimental system The results are expressed as a diffusive permeability coefficient P in centimeters per second. During the 120 minutes of the control stage, the rate of insulin and albumin bidirectional passage remained constant. Values of P +/- standard error of the mean did not correlate with the molecular weight of the compounds and measured 0.145 +/- 0.033 x 0.0001 cm/s and 0.146 +/- 0.022 x 0.0001 cm/s for insulin, and 0.271 +/- 0.056 x 0.0001 cm/s and 0.315 +/- 0.057 x 0.0001 cm/s for albumin in the I-->M and M-->I transport directions respectively. Application of sodium hyaluronan did not change the bidirectional transport of either solute. However sodium deoxycholate caused the values of P to increase by 142% (p < 0.05) for insulin I-->M transfer and by 102% (p < 0.02) for insulin M-->I transport. Albumin passage increased by 193% (p < 0.01) for both transfer directions. We conclude that, in vitro, sodium deoxycholate but not sodium hyaluronan increases the bidirectional peritoneal transport of insulin and albumin. In the case of larger molecular weight solutes, the modification is greater.

Recent studies pointed out advantages of high-molecular hyaluronic acid (HA) application into dialysis fluids. This molecule is an essential component of peritoneal extracellular matrix. The compound shows antiadhesive properties and participates in restoring of peritoneal integrality and remodeling of peritoneum, which have been changed by prolonged peritoneal dialysis and returning incidents of peritonitis. Influence of HA on transperitoneal transport of large and small molecules is recognized in a little range. The aim of presented studies in vitro was qualification of hyaluronan influence on transport dynamics of the selected macromolecules (albumin 1 g/dL, icodextrin 7.5 g/dL and insulin 0.1 g/dL). Values of the transfer, directed from the interstitial to the mesothelial side of membrane (I-->M) and in the opposite direction (M-->I) were expressed as coefficient of diffusive permeability P [cm/s]. In the case of each macromolecule, two separate research series of the experiments were done. In the first one transperitoneal transport in the control conditions (120 min) was analyzed, and in the secondtransfer parameters before (15-60 min) and after hyaluronan (0.04 g/dL) application on the mesothelial side of peritoneal membrane (75-120 min) were examined. Stability of albumin and insulin transport (in the case of the both transfer directions) and icodextin passage (only M-->I direction) was observed in the presented studies when we compare the first and the second hours of the experiments. In the opposite direction (I-->M) it was showed an increase of its transport with time by about 50%. The mean values of P +/- SEM amounted to 0,271 +/- 0,056 [x10(-4); cm/s] and 0,315 +/- 0,057 [x10(-4); cm/s] for albumin and 0,145 +/- 0,033 [x10(-4); cm/s] and 0,146 +/- 0,022 [x10(-4); cm/s] for insulin, respectively in the case of I-->M and M-->I directions and 0,194 +/- 0,035 [x10(-4); cm/s] for icodextrin transfer directed from the mesothelial to the interstitial side of membrane. In the opposite direction (I-->M) values of P coefficient amounted to: 0,280 +/- 0,038 [x10(-4); cm/s] in the first experimental hour, and 0,394 +/- 0,046 [x10(-4); cm/s] in the second one. It was observed also asymmetry of glucose polymer passage with I-->M transfer domination. Hyaluronan eliminated this asymmetry. After use this compound the transport parameters of icodextrin were stable for the both I-->M and M-->I directions. Hyaluronan did not change values of diffusive permeability coefficients P in the case of bidirectional transfer of albumin and insulin. The obtained results show, that values of macromolecules transfer across peritoneum in vitro don't depend on their molecular weight and isoelectric points. Dynamics of albumin and insulin transperitoneal passage is stable. Icodextrin transport, directed from the interstitial to the mesothelial side of membrane, predominates transfer in the opposite direction. Hyaluronan modifies dynamics of transperitoneal icodextrin passage, but doesn't influence on permeability of the membrane in the case of albumin and insulin.

We performed in vitro experiments with the isolated rabbit parietal peritoneum to evaluate the importance of fluid stirring intensification and of chemical modification of mesothelium and interstitium to the peritoneal transport of glucose and icodextrin. We used a mathematical model of mass transport to calculate the diffusive permeability coefficient, P, in centimeters per second. In control conditions (intact tissue; stirring rate: 11 mL/min), the rate of glucose (2.0 g/dL) transfer remained constant, and no differences were observed for transport from the interstitial to the mesothelial (I-->M) side of the membrane or in the opposite direction (M-->I). The value of P (+/- standard error of the mean) was 2.731 +/- 0.472 x 10(-4) cm/s. In contrast, the icodextrin (7.5 g/dL) I-->M transport rate was higher than that for M-->I (P: 0.319 +/- 0.038 x 10(-4) cm/s and 0.194 +/- 0.035 x 10(-4) cm/s respectively). Dynamics of the icodextrin M-->I transfer were constant, but I-->M increased by 50% over time. The intensification of the stirring rate increased the value of P at varying rates: the increase was greater for icodextrin than for glucose, and greater for the I-->M transport direction than for the M-->I direction for both solutes. Chemical modification (by 2.5 mmol/L sodium deoxycholate) increased glucose and icodextrin I-->M transfer a mean of 41% and 81% respectively, but increased M-->I transfer by 70% and 224% respectively. The dynamics of glucose and icodextrin peritoneal transfer in vitro are different: glucose diffusion is constant, but I-->M icodextrin transfer increases over time and is greater than M-->I transfer Fluid stirring intensification and chemical injury to the peritoneum enhance diffusion of glucose and icodextrin. Glucose and icodextrin M-->I transfer but not I-->M transfer is restricted more by tissue barriers than by stagnant fluid layers.

In the present study, we compared the influence of icodextrin (2 g/dL) on uric acid (20 mg/dL) and albumin (1 g/dL) transfer through isolated rabbit parietal peritoneum. In separate series of experiments, we used a mathematical model to calculate the transport rate of solutes from the interstitial to the mesothelial side of peritoneal membrane (I --> M) and in the opposite direction (M --> I) before and after introduction of glucose polymer. In control conditions, the rates of uric acid and albumin passage across the rabbit peritoneum remained constant. Mean values [x +/- standard error of the mean (SEM)] of the diffusive permeability coefficient P were 1.936 +/- 0.324 (I --> M) and 2.078 +/- 0.186 (M --> I) for uric acid and 0.341 +/- 0.066 (I --> M) and 0.389 +/- 0.084 (M --> I) for albumin (all x10(-4) cm/s), respectively. The introduction of glucose polymer into the experimental system did not alter the I --> M transport of either solute; but, in the opposite direction, it caused a 17% decline in the P for uric acid (p < 0.05), and an increase of 77% in the same parameter for albumin (p < 0.03). Hence, I --> M transfer dominated M --> I transfer of uric acid (p < 0.04). In contrast, in albumin transport, M --> I was higher than I --> M (p < 0.02). We conclude that, in vitro, icodextrin modifies the diffusive permeability of the peritoneum and induces transport asymmetry for some small and large solutes.

The effect of fluid mixing intensification, damage of mesothelial cells, gentamicin, and icodextrin on the diffusive glucose transport across the peritoneal membrane were evaluated in in vitro studies. A mathematical model of mass transport was used to calculate the diffusive permeability, expressed as a diffusive permeability coefficient (P). In the control conditions, the rate of glucose transfer from the interstitial to the mesothelial side of membrane (I-->M) and in the opposite direction (M-->I) remained constant, and the P value at mean was 2,731 +/- 1,493 x 10-4 (cm x s-1). The change of the stirring rate from 5.5 to 11 ml/min increased P values by about 74% for transport direction I-->M and 58% for M-->I, and the change from 11 to 22 ml/min enhanced P at mean by about 42% for both directions. The damage of the mesothelial layer, using sodium deoxycholate (2.5 mmol/L; 103.6 mg%), increased the glucose transfer from the interstitial to the mesothelial side of the peritoneum by 41% and to the opposite direction by 70%. Addition of icodextrin to the glucose solution increased glucose bidirectional transport at mean by about 14% for I-->M and 24% for M-->I. Furthermore, gentamicin did not change the I-->M transfer, but diminished M-->I transport by about 12%. In conclusion, the reduction of unstirred fluid layers at the mesothelium and the interstitium-fluid interfaces, removal of mesothelium, and addition of icodextrin increased the diffusive glucose transport in vitro; unstirred fluid layers restricted glucose transfer (I-->M) more than the mesothelium; and peritoneal glucose transport, directed from the mesothelial to the interstitial side of the peritoneum, decreased slightly after the addition of gentamicin.

Unlabelled: The effect of mixing fluid intensification, damage of mesothelial cells and gentamicin on the diffusive glucose transport across the peritoneal membrane were evaluated in the presented in vitro studies. A mathematical model of the mass transport was used to calculate the diffusive permeability, expressed as a diffusive permeability coefficient P [cm x s-1], for the investigated specimens. In the control conditions glucose transfer from the interstitial to the mesothelial side of membrane (I-->M) and in the opposite direction (M-->I) remained constant and P value at mean was 2.731 +/- 1.493 [cm x s-1 x 10(-4)]. The change of the stirring rate from 5.5 to 11 mL/min increased P values by about 74% for transport direction I-->M and 58% for M-->I, but change from 11 to 22 mL/min enhanced P at mean by about 42% for the both direction. The damage of the mesothelial layer, using of sodium deoxycholate (2.5 mmol/L; 103.6 mg%), increased the glucose transfer from the interstitial to the mesothelial side of the peritoneum by 41% and to the opposite direction by 57%. Furthermore, gentamicin did not change the I-->M transfer, but diminished M-->I transport by about 12%., In Conclusion: 1. The reducing of unstirred fluid layer at the mesothelium and interstitium--fluid interface and the mesothelium damage increase the diffusive glucose transport in vitro; 2. The unstirred fluid layer restricts glucose transfer more than tissue barrier (mesothelium); 3. The peritoneal glucose transport, directed from the mesothelial to the interstitial side of the peritoneum (but not transfer to the opposite direction), decreases slightly after gentamicin introduction.

The dynamics of bidirectional glucose transport across parietal peritoneum from anterior abdominal wall or diaphragm and small-bowel mesentery was analyzed. The mean transport values, expressed as transport coefficients, of intact peritoneum amounted 2.61; 0.18; 5.43 (10(-4) x cm x S-1), respectively. The chemical destruction of the mesothelium (2.5 mmol/l sodium deoxycholate) increased transperitoneal glucose transport across the investigated tissues. However, the intensification of transfer was different. Removal of the diaphragm pleural mesothelium caused greater increase of bidirectional glucose transport than the peritoneal mesothelium. Furthermore, the mean values of transport coefficient after peritoneal mesothelium damage were higher in relation to mesentery than to the peritoneum isolated from anterior abdominal wall and diaphragm. The obtained results suggest topographic heterogeneity of peritoneal membrane which refer to the mesothelium and submesothelial layers.

The changes of peritoneal absorption and excretion of urea, uric acid and gentamicin caused by glucose or mannitol have been analysed. These modification were differentiated, depended on the type of transported molecule, used osmotic agent and time of its activity as well as transfer direction. For example, glucose caused the increase of uric acid absorption and the decrease of urea excretion by about 40%. In contrast, mannitol didn't change the uric acid transport, but lowered the bidirectional transfer of urea. The mean values of gentamicin transport diminished after application of glucose or mannitol. This lowering was smaller in comparison with isoosmolar conditions. The reasons of above modifications are complex. It supposes that in vitro the direct physical action of hyperosmolality, metabolic activity of glucose and membrane effect of gentamicin balanced the solvent drag process. Furthermore, the heterogenecity of glucose and mannitol influence on the transperitoneal compounds transport are related to the transport rates (mechanism) of the examined osmotic agents and/or their metabolic activity.

The transperitoneal transport dynamics (removal) of guanidinoacetic acid (GAA) and guanidinosuccinic acid (GSA) has been determined in vitro in the control conditions and after application of furosemide (10(-4) mmol/l) on the mesothelial side of the membrane. GAA peritoneal transfer values, as a rule, were higher than GSA and equaled at mean, in the control series of experiments 0.132 i 0.068 mg x 10(-4) x cm-2 x s-2, respectively. Furosemide decreased GSA passage in 30 min after it addition by about 30%, but GSA transfer diminished later, in 120 min., by about 37%. Therefore, mean GAA transport values before (30-90 min.) and after application of furosemide (120-210 min.) were not statistically significant differentiated, whereas GSA transport parameters were lowered by about 40%. Heterogeneity of the peritoneal GAA and GSA transport dynamics in the control series of the experiments, as well as in the series with furosemide, may be related to the physico-chemical differences (e.g. molecular mass) of the analysed derivates.

The importance of the stagnant fluid layers and the mesothelial barrier in the peritoneal absorption and excretion of methotrexate (MTX) in vitro was analysed. In case of intact rabbit parietal peritoneum and a constant fluid flow rate, an asymmetry in the MTX transport and the decrease of its magnitude in time were found. The increase of stirring intensity and mechanical destruction of mesothelium caused an increase and stabilization of the values of the bidirectional transfer of the drug. This increase was higher in case of a smaller flow speed giving on the average 151%, and in case of the destruction of mesothelium it was 203% in comparison with control conditions. The obtained results indicate that in transperitoneal transfer of MTX in vitro, more important is the tissue-type barrier (mesothelium) than the diffusion barrier (stagnant fluid layer).

The changes of the transperitoneal molecules transport caused by glucose and dynamics of its transport have been determined in the case of undamaged tissue and the membrane with injured mesothelium in the in vitro studies. In the intact glucose induced increase of peritoneal uric acid absorption (40%) and lowering of urea and gentamicin excretion (25-40%). Glucose in the dialysis fluid lowered uric acid absorption and urea excretion (20-40%) in denuded animal peritoneum. The transperitoneal glucose transport remained constant at 2.61 x 10(-4) x cm x s-1. The mesothelium destruction caused an increase (32%) of mean values of absorption and excretion of this compound. The obtained results suggest that modifications of transport functions of the peritoneum caused by glucose depend rather on direct action of hypertonicity and metabolic effects of glucose than of the osmotic gradient. Furthermore, these changes may contribute to the rapid transperitoneal transport of glucose which increase after the destruction of the mesothelium.

It was shown elsewhere that in a peritoneally dialyzed woman with pulmonary tuberculosis, oral treatment with rifampicin and pyrazinamide (11 and 25 mg/kg/day, respectively) caused a decrease in the peritoneal transport of sodium, potassium, urea, uric acid, protein, and ultrafiltration rate by 48% to 75% compared to the pretreatment values. Pyrazinoic acid (PA), a metabolite of pyrazinamide, may account for these changes, because rifampicin was also previously used in this patient without peritoneal function impairment. Thus in the present study the influence of PA on the human peritoneum is examined using the modified Ussing-type chamber. PA (1 mg/dL) was introduced into the medium on the interstitial side of the membrane. After the introduction of PA, uric acid transfer from the interstitial to the mesothelial side decreased by about 50%. There were no significant changes in the urea and albumin transfer rates. In conclusion, PA induces changes in uric acid transfer acting directly on mesothelial cells, whereas a decrease in the peritoneal transfer of other solutes may be caused by a decrease in convective transfer rates due to impaired ultrafiltration.

Bidirectional transport across rabbit parietal peritoneum of urea, uric acid, gentamycin and albumin were examined in control conditions and after mechanical or chemical mesothelium damage. The transport mean values, exprerssed as transport coefficients, of intact peritoneum amounted 1.37; 1.18; 4.30; 0.20 [10(-4) cm s-1] respectively. The destruction of mesothelial barrier increased, in similar range, both absorption and excretion component of the transport of urea, uric acid and albumin but not gentamycin. In the latter case, mesothelium injury enhanced peritoneal excretion by 86% and absorption by 162%. An asymmetry in gentamycin transport was observed which can be unfavourable for peritoneal dialysis patients.

The paper is a review of the literature describing the multidirectional effects of hyperglycemic solutions used during peritoneal dialysis. The changes of general system metabolism, functions of free cells in peritoneal cavity, structure and functions of peritoneal membrane are analysed.

An effect of gentamicin on urea and uric acid transfer through peritoneum was studied in rabbits in vitro. It was found that gentamicin decreases urea transfer by approximately 30%. Its effect on uric acid transfer was transient so as mean values of this parameter did not differ statistically before and after antibiotic administration. It may be assumed that gentamicin decreases permeability of peritoneum for certain low molecules of endogenic origin. Such an effect may prove unfavourable when peritoneal dialysis efficiency is concerned.

This paper is a review of the literature describing some aspects of intraperitoneal pharmacotherapy in experimental and clinical conditions. The principles of peritoneal absorption of antibiotics, insulin, nutrition agents (glucose, fat and amino acids) and antineoplastic drugs are analysed.

Bidirectional transport of the urea, uric acid and albumin across parietal peritoneum was investigated in vitro under both normal conditions and following an administration of pyrazinoic acid. It was found that pyrazinoic acid decreased urea and uric acid transport from interstitial to mesothelial surface of the peritoneal membrane but did not affect the transport in reverse direction. Bidirectional transport of albumin remained unchanged. The obtained results are similar to those reported earlier and suggest that pyrazinamide actions are partially selective.

The article is an analysis of the dynamics of two-direction transportation of uric acid (UA) through the human peritoneum in vitro, and also changes of the dynamics under the influence of pyrazinoic++ acid. The peritoneum was taken from the anterior abdominal wall of patients undergoing planned abdominal surgery. It was found that the transportation of UA both from the vascular to the mesothelial side of the peritoneal membrane and in the opposite direction remained on a stable level for 120 minutes. The introduction of pyrazinoic++ acid decreased the transportation of UA from the vascular to the mesothelial side of the peritoneum on the average by 50 per cent. The transportation in the opposite direction did not change. The results obtained are consistent with results of clinical examinations. One may suppose that pyrazinoic++ acid induces changes in transportation qualities of the peritoneum.

The effect of monocrotofos (in a concentration of 4.5 X 10(-3)M) on the bioelectric parameters of rabbit intestinal epithelium was compared with a similar effect on these parameters of frog skin. It was demonstrated that the tested pesticide added to the medium on the mucosal side of the intestinal wall or on the external side of frog skin caused no evident changes in the potential difference (PD), short-circuit current (CC) and resistance of the studied tissues. This suggested absence of monocrotophos-binding receptors on the external surface of these epithelial structures. The pesticide applied to the serosal side of the intestine decreased PD and SCC without changing the resistance. Applied to the internal surface of frog skin it raised the PD and SCC with some decrease of the resistance. The different pattern of the response could be due to structural differences and to species-specific differences of these epithelia.