Effect of P2Y-purinoceptor stimulation on renal gluconeogenesis in rats.

In the freshly prepared rat renal cortical tubule suspension, the effects of ATP on intracellular free calcium mobilization and gluconeogenesis were investigated. ATP increased intracellular free calcium concentration ([Ca2+]i) in a dose-dependent manner (10(-6) - 10(-3) M). The rank order in the potency of ATP analogs at 10(-4) M was 2-methylthio ATP > ATP > or = ADP. AMP, adenosine and alpha, beta-methylene ATP did not respond to [Ca2+]i. These results suggest that P2-purinoceptor in the rat kidney cortex should be specifically P2Y subtype. Renal gluconeogenesis from pyruvate was stimulated maximally by 10(-4) M ATP (48.3 +/- 13.2%). This effect was significantly inhibited by 10(-4) M suramin. Thus, the present study suggests that renal gluconeogenesis is increased via P2Y-specific purinoceptor stimulation.