Co-storage and co-secretion of somatostatin and catecholamine in bovine adrenal medulla.

Co-storage and co-secretion of somatostatin (SRIF) and catecholamine (CA) were demonstrated using bovine adrenal medulla. In the experiment of retrograde perfusion system of isolated adrenal gland, the basal concentration of immunoreactive (IR)-SRIF was 20 pg/4 ml/min, but a significant increase of the value (142 pg/4 ml/min) was observed at 1-2 min after a brief infusion of acetylcholine (10 mM) and the marked release continued for over 6 min. Similar result was obtained for CA release. On gel-filtration chromatography of a soluble lysate of chromaffin vesicles prepared by differential and discontinuous sucrose density centrifugation, IR-SRIF was separated into three components with molecular sizes corresponding to prepro-SRIF (76.8% of the total immunoreactivity), SRIF28 (14.1%) and SRIF14 (9.1%).