EFFECT OF P-2Y-PURINOCEPTOR STIMULATION ON RENAL GLUCONEOGENESIS IN RATS

In the freshly prepared rat renal cortical tubule suspension, the effe cts of ATP on intracellular free calcium mobilization and gluconeogene sis were investigated. ATP increased intracellular free calcium concen tration ([Ca2+](i)) in a dose-dependent manner (10(-6) - 10(-3) M). Th e rank order in the potency of ATP analogs at 10(-4) M was 2-methylthi o ATP>ATP greater than or equal to ADP. AMP, adenosine and alpha,beta- methylene ATP did not respond to [Ca2+](i). These results suggest that P-2-purinoceptor in the rat kidney cortex should be specifically P-2Y subtype. Renal gluconeogenesis from pyruvate was stimulated maximally by 10(-4) M ATP(48.3 +/- 13.2%). This effect was significantly inhibi ted by 10(-4) M suramin. Thus, the present study suggests that renal g luconeogenesis is increased via P-2Y-specific purinoceptor stimulation . (C) 1995 Academic Press, Inc.