Immunoreactive somatostatin release from rat spinal cord in vitro.

A calcium-dependent release of immunoreactive somatostatin from rat spinal cord in vitro in response to two depolarising stimuli (60 mM KCl and 75 micrometer veratrine) has been demonstrated. Released somatostatin immunoreactivity comprised 0.53% of total tissue content, showed parallelism when serial dilutions were compared to the immunoassay dose-response curve and eluted similarly to synthetic somatostatin on Sephadex G-25 (f) chromatography. These results provide further evidence for a neurotransmitter or neuromodulator role for somatostatin in mammalian spinal cord.