Somatostatin binding to dissociated cells from rat cerebral cortex

A method has been developed for the study of somatostatin (SS) binding to dissociated cells from rat cerebral cortex. Binding of [125I] [Tyr11]SS to cells obtained by mechanical dissociation of rat cerebral cortex was dependent on time and temperature, saturable, reversible and highly specific. Under conditions of equilibrium, i.e., 60 min at 25 degrees C, native SS inhibited tracer binding in a dose-dependent manner. The Scatchard analysis of binding data was linear and yielded a dissociation constant of 0.60 +/- 0.08 nM with a maximal binding capacity of 160 +/- 16 fmol/mg protein. The binding of [125I] [Tyr11]SS was specific as shown in experiments on tracer displacement by the native peptides, SS analogues, and unrelated peptides.