URINARY CALCIUM EXCRETION AND RENAL CALBINDIN-D28K

Citation
C. Hemmingsen et al., URINARY CALCIUM EXCRETION AND RENAL CALBINDIN-D28K, Kidney & blood pressure research, 20(4), 1997, pp. 247-250
Citations number
25
Categorie Soggetti
Physiology,"Urology & Nephrology
ISSN journal
14204096
Volume
20
Issue
4
Year of publication
1997
Pages
247 - 250
Database
ISI
SICI code
1420-4096(1997)20:4<247:UCEARC>2.0.ZU;2-2
Abstract
The present investigation examined the possible influence of urinary c alcium excretion on the concentration of renal calbindin-D28k. Thiazid e diuretics stimulate calcium transport across the epithelial cells of the distal tubule, which express calbindin-D28k in high concentration s. Calbindin-D28k is assumed to facilitate transcellular Ca diffusion. Reduced urine calcium excretion and increased urine output were induc ed in Wistar rats by infusion of bendroflume-thiazide 1 mg/kg/day. The two control groups had infusions of either furosemide 20 mg/kg/day or vehicle. n = 8 in each group. Urinary Ca excretion was reduced to 10% in the thiazide group and increased by 50% in the furosemide group. l ienal concentrations of calbindin-D28 showed no difference between veh icle, thiazide- and furosemide-treated rats. No differences in plasma concentrations of calcium, magnesium, phosphorus, urea, PTH, calcitoni n and 1,25-(OH)(2)D were found between the groups. The present study d escribes that urine calcium excretion selectively can be manipulated w ithout accompanying changes in renal calbindin-D28k concentrations. Th e data, therefore, suggest that urinary calcium excretion is not a sig nificant determinator of cytosolic concentrations of renal calbindin-D 28k.