Somatostatin-14 increases the inositol-1,4,5-trisphosphate content in various areas of the brain.

The effects of somatostatin-14 on inositol-1,4,5-trisphosphate (IP3) content were examined in rat pituitary, hippocampus and cortex homogenates. Somatostatin increased IP3 concentration in all these investigated regions in a dose- and time-dependent manner. Maximal increase of IP3 content was found in the pituitary homogenate, and in the hippocampal and cortex homogenates the IP3 argumentation was slightly smaller. Time-response studies showed that this effect declined with extended time of incubation. These results suggest that IP3 is involved in the mechanism of action of somatostatin in brain.