Kidneys membrane vesicle

Biochemical studies of plasma membrane Na /H exchangers have been directed at two major goals (1) identification of amino acids that are involved in the transport mechanism and (2) identification and characterization of the transport pro-tein(s). To date, most studies have been performed on the amiloride-resistant form of Na /H" exchanger that is present in apical or brush border membrane vesicles from mammalian kidney, probably because of the relative abundance of transport activity in this starting material. However, some studies have also been performed on the amiloride-sensitive isoform present in non-epithelial cells. 

Other blockers of epithelial Cl -channels are of the aryl-amino-benzoate type or phenoxy-acetic-acid type [70]. Very few systematic surveys comparing different classes of blockers in one type of Cl -channel are available at this stage. One such study has been performed in membrane vesicles from kidney cortex [80]. In this study IAA-94 and NPPB (cf. Fig. 2) turned out to be the most potent blocker of conductive Cl -flux. In another systematic survey the Cl -conductance of the sweat duct was examined, and it was found that dichloro-DPC (Fig. 2) was the most potent inhibitor of the transepithelial Cl -conductance [90]. 

Inui, K., Saito, H. and Hori, R. (1985). H+ gradient-dependent active transport of tetaethyl-ammonium cation in apical-membrane vesicles isolated from kidney epithelial cell line LLC-PK Biochem. J. 227 199-203. 

Kasher, J.S., Holohan, P.D. and Ross, C.R. (1983). Effect of cephaloridine on the transport of organic ions in dog kidney plasma membrane vesicles. J. Pharmacol. Exp. Ther. 225(3) 606-610. 

Williams, P.D. and Hottendorf, G.H. (1985). Effects of cw-dichlorodiamineplatinum-II (Cisplatin) on organic ion transport in membrane vesicles from rat kidney cortex. Cancer Treat. Rep. 69 875-880. 

Kidney Uptake Blood Epithelial cells Kidney slices, isolated and cultured renal epithelial cells, basolateral membrane vesicles, transporter expressions system... 

Kinne-Saffran E, Kinne RK. Isolation of lumenal and contralumenal plasma membrane vesicles from kidney. Methods Enzymol 1990 191 450-469. 

Miirer, H Hopfer, U., Kinne, R. (1976). Sodium/proton antiport in brush border membrane vesicles isolated from rat small intestine and kidney. Biochem. J. 154,597-604. 

A. M. Lynch and J, D, McGivan, Evidence for a single common Na+-dependent transport system for alanine, glutamine, leucine and phenylalanine in brush-border membrane vesicles from bovine kidney, Biochim. Biophys. Acta, 899 176-184 (1987). 

S. H. VWight, Transport of Nt-methylnicotinamide across brush border membrane vesicles from rabbit kidney. Am.. Physid., 249 F903-F911 (1985). 

L. G. Gisclon, E M. Wong, and K. M. Giacomini, Cimetidine transport in isolated luminal membrane vesicles from rabbit kidney. Am. J. Physiol., 253 F141-n50 (1987). 

R. Bendayan, E. M. Sellers, and M. Silverman, Inhibition kinetics of cationic drugs on N -methylnicotinamide uptake by brush border membrane vesicles from the dog kidney cortex. Can. J. Physiol. Pharmacol., 68 467-475 (1990). 

Sokol, PP, Mechanism of vancomycin transport in the kidney studies in rabbit renal brush border and basolateral membrane vesicles. Am J Kidney Dis, 1991,259(3) 1283-87. 

Williams PD, Hitchcock MJ, Hottendorf GH. Effect of cephalosporins on organic ion transport in renal membrane vesicles from the rat and rabbit kidney cortex. Res Commun Chem Pathol Pharmacol 1985 47(3) 357-371. 

Inui K, Saito H,Takano M, OkanoT, Kitazawa S, Hori R. Enzyme activities and sodium-dependent active D-glucose transport in apical membrane vesicles isolated from kidney epithelial cell line (EEC-PK1). Biochim Biophys Acta 1984 769(2) 514-518. 

Foscarnet competitively inhibits Na -Pj cotransport in animal and human kidney proximal tubule brush border membrane vesicles, reversibly inhibiting sodium-dependent phosphate transport [48, 49]. Renal cortical Na-K-ATPase and alkaline phosphatase activity are not inhibited by foscarnet, nor is proline, glucose, succinate, or Na" transport [48,49]. Foscarnet induces isolated phosphaturia without hypophosphatemia in thyroparathyroidectomized rats maintained on a low phosphorus diet, without affecting glomerular filtration rate, urinary adenosine 3 5 -cyclic monophosphate (cAMP) activity, or urinary calcium, sodium or potassium excretion [48,50]. Sodium-Pj cotransport in brush border membrane vesicles from human renal cortex was reported to be even more sensitive to inhibition by foscarnet than in rat renal brush border membrane vesicles [49]. 

Some recent studies on vitamin transport using membrane vesicles include those of vitamin B6 by rat kidney brush border membranes (Bowman et al, 1990), ascorbic acid by teleost intestinal brush border membranes (Mafha et ai, 1993), biotin by human kidney brush border membranes (Baur and Baumgartner, 1992), pantothenate by human placental brush border membranes (Grassl, 1992), folate and riboflavin by rabbit intestinal brush border membranes (Said and Mohammadkhani, 1993a,b Said et al, 1993), and thiamine by rat small intestine basolateral membranes (Laforenza et al, 1993). Bile acid transport in human placental, rat ileal, and rabbit small intestinal brush border membrane vesicles (Dumaswala et al, 1993 Gong et al, 1991 Kramer et al, 1993) and the effect of vitamin D status... 

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