Search

Oxidative stress and endothelial dysfunction contribute substantially to the pathogenesis of preeclampsia (PE). Decidual mesenchymal stem/stromal cells (DMSC), reportedly reduce endothelial cell dysfunction and alleviate PE-like symptoms in a murine model. However, as a therapeutic strategy, the use of whole DMSC presents significant technical limitations, which may be overcome by employing DMSC-secreted extracellular vesicles (DMSC_EV). DMSC_EV restoration of endothelial dysfunction through a paracrine effect may alleviate the clinical features of PE., Objective: To determine whether DMSC-secreted, extracellular vesicles (DMSC_EV) restore endothelial cell function and reduce oxidative stress., Methods: DMSC were isolated from the placentae of uncomplicated term pregnancies and DMSC_EV prepared by ultracentrifugation. Human umbilical vein endothelial cells (HUVEC) were treated with bacterial lipopolysaccharide (LPS), or with serum from PE patients, to model the effects of PE. DMSC_EV were then added to treated HUVEC and their growth profiles, inflammatory state, and oxidative stress levels measured., Results: DMSC_EV displayed characteristic features of extracellular vesicles. In both LPS- and PE serum-treatment models, addition of DMSC_EV significantly increased HUVEC cell attachment and proliferation, and significantly reduced production of pro-inflammatory cytokine IL-6. The addition of DMSC_EV to LPS-treated HUVEC had no significant effect on total antioxidant capacity, superoxide dismutase levels or on lipid peroxidation levels. In contrast, the addition of DMSC_EV to PE serum-treated HUVEC resulted in a significant reduction in levels of lipid peroxidation., Conclusion: Addition of DMSC_EV had beneficial effects in both LPS- and PE serum- treated HUVEC but the two treatment models to induce endothelial cell dysfunction showed differences. The LPS treatment of HUVEC model may not accurately model the endothelial cell dysfunction characteristic of PE. Human cell culture models of PE show that DMSC_EV improve endothelial cell dysfunction in PE, but testing in in vivo models of PE is required., (Copyright © 2020 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.)

Background: Evaluation of the effects of candidate drugs on the nervous system in preclinical safety pharmacology studies utilises a global neurobehavioral assessment, usually in the rat. This either takes the form of the functional observational battery (FOB) or modified Irwin Test, both of which evaluate effects across 4 functional domains: autonomic, neuromuscular, sensorimotor and behavioral. Although there is a great deal of overlap in the parameters they address, the two tests approach the assessments slightly differently. We undertook a broad pharmacological validation of both the FOB and the Irwin test, and compared the two outcomes., Methods: Male rats (6 per treatment group) were used to assess each of 12 reference drugs alongside vehicle controls in separate FOB and Irwin studies. The drugs compared in the two study types were chlorpromazine, chlordiazepoxide, clonidine, baclofen, (+)-amphetamine, harmaline, 8-hydroxy-2-(di-n-propylamino)tetralin, buspirone, physostigmine, picrotoxin, yohimbine and atropine. There is a high degree of semantic equivalence in the parameters assessed in the autonomic domain between the two tests, with a lower degree of equivalence for neuromuscular and behavioral domains, whereas sensorimotor reflex testing in the FOB is far more extensive than in the Irwin test., Results: Across the set of reference drugs, concordance between the two tests was generally good across the 4 functional domains at the 'domain' level (i.e., detecting 'an effect'), whereas there was generally a poor concordance at the individual parameter level. However, this was partially explained by variability between repeated studies on a single reference drug using the same test (FOB or Irwin)., Conclusions: Both tests are 'fit-for-purpose' in detecting effects of candidate drugs on the nervous system. We would encourage the global safety pharmacology community to consider whether (a) the tests could be combined into one industry standard; (b) candidate drugs could be triaged according to CNS penetration, with the level of scrutiny in the CNS core battery assessment adjusted accordingly and (c) whether new home cage technology could be applied to semi-automate the preclinical neurobehavioral assessment., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The ActualHCA™ system continuously monitors the activity, temperature and behavior of group-housed rats without invasive surgery. The system was validated to detect the contrasting effects of sedative and stimulant test agents (chlorpromazine, clonidine and amphetamine), and compared with the modified Irwin test (mIT) with rectal temperature measurements., Methods: Six male Han Wistar rats per group were used to assess each test agent and vehicle controls in separate ActualHCA™ recordings and mIT. The mIT was undertaken at 15, 30 mins, 1, 2, 4 and 24 h post-dose. ActualHCA™ recorded continuously for 24 h post-dose under 3 experimental conditions: dosed during light phase, dark phase, and light phase with a scheduled cage change at the time of peak effects determined by mIT., Results: ActualHCA™ detected an increase stimulated activity from the cage change at 1-2 h post-dose which was obliterated by chlorpromazine and clonidine. Amphetamine increased activity up to 4 h post-dose in all conditions. Temperature from ActualHCA™ was affected by all test agents in all conditions. The mIT showed effects on all 3 test agents up to 4 h post-dose, with maximal effects at 1-2 h post-dose. The maximal effects on temperature from ActualHCA™ differed from mIT. Delayed effects on activity were detected by ActualHCA™, but not on mIT., Conclusions: Continuous monitoring has the advantage of capturing effects over time that may be missed with manual tests using pre-determined time points. This automated behavioural system does not replace the need for conventional methods but could be implemented simultaneously to improve our understanding of behavioural pharmacology., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: We evaluated the feasibility of providing food and water to rodents during whole body plethysmography (WBP) studies as a welfare improvement to standard conditions., Methods: Male Han Wistar rats or CD1 mice (n=8) were placed in WBP chambers and respiratory parameters recorded for approximately 6h on four separate occasions. On each occasion the animals were exposed to a different plethysmography chamber environment using a randomised design: no food/water (the standard conditions), water bottle, hydrating gel and wet food. In a further session, rats (n=8) were administered theophylline, or vehicle and respiratory parameters measured in the plethysmography chamber containing wet food., Results: Respiratory parameters of rats were not significantly altered by the provision of water or food. Providing wet food resulted in reduced body weight loss. Administration of theophylline caused the expected increase in respiratory rate. When mice were given access to hydrating gel or wet food the respiratory parameters were significantly affected; respiratory rate and tidal volume were increased. Providing wet food resulted in reduced bodyweight loss., Discussion: The provision of food and water did not impact on respiratory parameters in rats placed in WBP chambers. When provided with wet food, rats lost less bodyweight. Therefore, to improve welfare conditions for rats during WBP respiratory studies wet food should be provided when appropriate to the study design. In mice, provision of food and water led to changes in respiratory parameters, therefore these improvements in welfare conditions are not suitable for mice., (Copyright © 2017. Published by Elsevier Inc.)

Unlabelled: Limited toxicokinetic data is generated during modified Irwin screen and whole body plethysmography safety pharmacology studies, due to disturbance of primary endpoints by standard blood sampling methods. We evaluated if incorporation of microsampling would impact on data quality, as providing toxicokinetic data from main test animals could reduce the need for satellite animals., Methods: A modified Irwin screen was performed, testing oral clonidine (0, 0.03, 0.1, or 0.3 mg/kg). One cohort of rats per dose level underwent standard blood sampling (post-4 h Irwin assessment), and another cohort underwent microsampling after the 0.5, 1, 2, 4 and 24 h Irwin assessments. The respiratory effects of oral theophylline (0 or 10 mg/kg) and oral baclofen (0 or 5 mg/kg), were tested using whole body plethysmography. Groups of animals underwent standard blood sampling (at end of recording at 4 h post-dose) or microsampling at either 0.5 h or 1 h intervals (4 or 8 microsamples, respectively)., Results: Microsampling did not impact on the quality of the data generated. The expected effects of clonidine on behavioural parameters, and of theophylline and baclofen on changes in ventilatory parameters were observed at a similar magnitude and duration independent of sampling method., Discussion: The incorporation of multiple capillary microsamples into the modified Irwin or respiratory study did not adversely affect the primary endpoints. The capillary microsampling method is a refinement in blood sampling technique which can easily be adapted into safety pharmacology studies to generate pharmacokinetic profiles within the same animal as the primary data, thus enhancing scientific robustness and reducing the satellite animals required., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: Parts A and B of the ICH S7 guidelines on safety pharmacology describe the in vivo studies that must be conducted prior to first time in man administration of any new pharmaceutical. ICH S7A requires a consideration of the sensitivity and reproducibility of the test systems used. This could encompass maintaining a dataset of historical pre-dose values, power analyses, as well as a demonstration of acceptable model sensitivity and robust pharmacological validation. During the process of outsourcing safety pharmacology studies to Charles River Laboratories, AstraZeneca set out to ensure that models were performed identically in each facility and saw this as an opportunity to review the inter-laboratory variability of these essential models., Methods: The five in vivo studies outsourced were the conscious dog telemetry model for cardiovascular assessment, the rat whole body plethysmography model for respiratory assessment, the rat modified Irwin screen for central nervous system assessment, the rat charcoal meal study for gastrointestinal assessment and the rat metabolic cage study for assessment of renal function. Each study was validated with known reference compounds and data were compared across facilities. Statistical power was also calculated for each model., Results: The results obtained indicated that each of the studies could be performed with comparable statistical power and could achieve a similar outcome, independent of facility., Discussion: The consistency of results obtained from these models across multiple facilities was high thus providing confidence that the models can be run in different facilities and maintain compliance with ICH S7A and B., (Copyright © 2013 Elsevier Inc. All rights reserved.)