Effects of insulin-induced hypoglycemia on somatostatin level and binding in rat cerebral cortex and hippocampus.

The effects of severe insulin-induced hypoglycemia on somatostatin level and specific binding in the cerebral cortex and hippocampus were examined using 125I-Tyr11-somatostatin as a ligand. Severe insulin-induced hypoglycemia did not affect the level of somatostatin-like immunoreactivity in the brain areas studied. However, the number (but not the affinity) of specific somatostatin receptors was significantly decreased in membrane preparation from the hippocampus but not in the cerebral cortex at the onset of hypoglycemic coma (5-10 min). Administration of glucose at the onset of hypoglycemic coma brought about extensive recovery of hippocampal somatostatin receptor number. These results suggest that glucose modulates the somatostatin receptor in the rat hippocampus. The physiological significance of these findings remains to be clarified.