A Model of Calcium Transport and Regulation in the Proximal Tubule.
The objective of this study was to examine theoretically how Ca2+ reabsorption in the proximal tubule (PT) is modulated by Na+ and water fluxes, parathyroid hormone (PTH), SGLT2 inhibitors, and acetazolamide. To do so, we expanded a previously published mathematical model of water and solute transport in the rat PT (Layton AT, Vallon V, and Edwards A. Am J Physiol Renal Physiol 308: F1343-F1357, 2015) that did not include Ca2+. Our results indicate that Ca2+ reabsorption in the PT is primarily driven by the transepithelial Ca2+ concentration gradient that stems from water reabsorption, which is itself coupled to Na+ reabsorption. Simulated variations in permeability or transporter activity elicit opposite changes in paracellular and transcellular Ca2+ fluxes, whereas a simulated decrease in filtration rate lowers both fluxes. The model predicts that PTH-mediated inhibition of the apical Na+/H+ exchanger NHE3 reduces Na+ and Ca2+ transport to a similar extent. It also suggests that acetazolamide- and SGLT2 inhibitor-induced calciuria at least partly stems from reduced Ca2+ reabsorption in the PT. In addition, the back-leak of phosphate (PO4) across tight junctions is predicted to reduce net PO4 reabsorption by about 20% under normal conditions. When transcellular PO4 transport is substantially reduced by PTH, the paracellular PO4 flux is reversed and contributes significantly to PO4 reabsorption. Furthermore, PTH is predicted to exert an indirect impact on PO4 reabsorption, vi...
Authors: Karimi G, Vard B, Riyahi R, Motlagh ME, Heshmat R, Kelishadi R Abstract This cross-sectional study was conducted among 14,400 Iranian students, aged 7-18 years to determine the association between the frequency of family dinner and mental health. Family dinner frequency, family relationship, life satisfaction (LS), self-perceived health and anxiety were assessed by validated questionnaires. Of 14,274 participants, 50.6% were boys and 71.4% were urban residents, with a mean (SD) age of 12.28 (3.16) years. Family dinner frequency was significantly correlated with LS (boys: β = 0.27, p
In this study we explored the use of a natural compound rubusoside (RUB) as a solubilizer to enhance the solubility of a fluorescence-labeled C6-Ceramide (NBD C6-Ceramide) and to characterize its pharmacokinetics and tissue distribution in an animal model. RUB significantly enhanced the solubility of NBD C6-Ceramide by forming nanomicelles, and efficiently delivered NBD C6-Ceramide in rats by oral and intravenous administration. RUB loaded 1.96% of NBD C6-Ceramide in the nanomicelles and solubilized it to a concentration of 3.6 mg/mL in water. NBD C6-Ceramide in nanomicelles remained stable in aqueous solutions, all...
Publication date: Available online 10 December 2019Source: Prostaglandins &Other Lipid MediatorsAuthor(s): Giorgio Mottola, Evan Werlin, Bian Wu, Mian Chen, Anuran Chatterjee, Melinda Schaller, Michael S. ConteAbstractInflammation ensuing from vascular injury promotes intimal hyperplasia (IH) and restenosis. Resolvin D1 (RvD1) is a lipid mediator that attenuates IH in vivo when delivered locally to the vessel wall in animal models. We tested the hypothesis that peri-procedural oral administration of RvD1 could blunt the local inflammatory response to angioplasty, and attenuate downstream IH. Carotid angioplasty was per...
First-of-its-kind trial evaluates decision aid’s efficacy
Authors: Glauser W PMID: 31818934 [PubMed - in process]
Authors: Owens B PMID: 31818933 [PubMed - in process]
Authors: Dermer M, Martel J, Greenhill A PMID: 31818932 [PubMed - in process]
Authors: Robson R PMID: 31818931 [PubMed - in process]
Authors: Lamb S PMID: 31818930 [PubMed - in process]
Authors: Zimmer V, Glanemann M, Lammert F PMID: 31818929 [PubMed - in process]