Presence of two molecular weight forms of somatostatin in neurons from chick embryo cerebral hemispheres in culture

Following its isolation hypothalamic extracts [l] the tetradecapeptide somatostatin (SS-14) has been found to be widely distributed throughout the central nervous system [2], the gastrointestinal tract and the pancreas [3]. Evidence for synthesis of SS-14 by cerebral cells in culture has also been reported (4,5]. We report here that neurons from chick embryo cerebral hemispheres, cultured in serum-free medium, are able to synthetize and to release two distinct molecular forms of somatostatin: one is identical to SS-14 and the other has a similar Mr-value to, but different from SS-28, an amino-terminally extended peptide from SS14 [6].