[Study of mechanism of PTH modulating cytosolic free calcium in rat DCT].

OBJECTIVE AND METHODS

In order to understand the mechanism of PTH in regulating cytosolic free calcium concentration ([Ca2+]i), we differentiated rat renal proximal and distal convoluted tubules (PCT&DCT) by Percoll density gradient centrifugation, and successfully gauged the effect of hPTH (1-84), dibutyryl cAMP (db cAMP, a kind of cAMP activator) and prostaglandin E2 (PGE2) on [Ca2+]i of DCT using fluorescent Ca2+ indicator Fluo 3-AM. We found that PTH, db cAMP and PGE2 all could increase [Ca2+]i.

RESULTS

The results suggest that the rise in [Ca2+]i induced by PTH in DCT was through activation of cAMP, and PGE2 might be also involved in regulation of [Ca2+]i as a messenger of PTH.