Comparison of the effects of calcium alpha-glycerophosphate and Ca2+ on prostaglandin synthesis in rabbit kidney medulla slices.

The stimulatory effects of calcium alpha-glycerophosphate (CaG) and Ca2+ on the generation of medullary prostaglandin E2 have been compared. CaG (4mM) was significantly more effective than Ca2+ (4 mM) as a stimulus for prostaglandin E2 release. This effect of CaG was most pronounced in the presence of exogenous phospholipase A2 (0.1 unit/ml). These results suggest that CaG has a more powerful stimulatory effect on prostaglandin E2 formation than Ca2+ because of its high affinity for phospholipase A2.