Renal abnormality of calcium handling in spontaneously hypertensive rats
Kamijo, T.; Gonzalez, J.M.; Jost, L.J.; Barrios, R.; Suki, W.N.
Kidney International. Supplement 55: S166-S168
1996
ISSN/ISBN: 0098-6577 PMID: 8743545 Document Number: 457587
Hypercalciuria has been observed in human and experimental hypertension. The distal convoluted tubule (DCT) is the site of fine regulation for Ca-2+ excretion. We assessed the cellular factors responsible for Ca-2+ reabsorption in the DCT of spontaneously hypertensive rats (SHR). Vitamin D3 dependent Ca-binding protein 28k (CaBP-28k), a factor involved in Ca-2+ influx, and plasma membrane Ca ATPases (PMCA), a factor involved in Ca-2+ efflux, were studied in hypertensive 16-week-old SHR and normotensive Wistar-Kyoto rats (WKY). mRNA levels for CaBP-28k, PMCA 2 and PMCA 4 were not different in the two strains. However, CaBP-28k protein was more abundant, and PMCA protein was less abundant in SHR than in WKY. PMCA antibody recognized only DCT in the two strains. In conclusion, decreased PMCA in DCT may be responsible for the hypercalciuria in SHR.