Effects of hypocalcemia on Ca2+ metabolism of microsomes from rat kidney cortex were studied. Microsomal activities of Ca2+-ATPase, Mg2+-ATPase and (Na++K+)-ATPase increased 30-33 days after Ca2+ restriction or low Ca2+-vitamin D depletion, but alkaline phosphatase activity decreased. Calcium repletion in diet and injection of lα-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol were partially successful in returning Ca2+-ATPase and Mg2+-ATPase activity, but not (Na++K+)-ATPase and alkaline phos-phatase activity, to normal. Correlations between serum Ca2+ level and both ATPase activities were significant. ATP-dependent Ca2+ uptake of microsomes was not affected by hypocalcemia and vitamin D metabolites.
- ATPase of microsomes
- Ca uptake in microsomes
- Calcium repletion
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine