Immunoreactive somatostatin in human pancreatic secretion.

Somatostatin in human pancreatic juice collected during endoscopic retrograde cholangiopancreatography following secretin injection was determined by RIA. The mean immunoreactive somatostatin (IRS) levels in the pancreatic juice of 13 non-diabetics was 78 +/- 11 (SE) pg/ml. The IRS levels in 4 non-insulin-dependent diabetics ranged from 843 to 2286 pg/ml with a mean of 1559 +/- 392 (SE) pg/ml. This was significantly greater than non-diabetic values. The IRS in the pancreatic juice was immunologically indistinguishable from somatostatin14 but consisted of 2 major components, one corresponding to somatostatin14 and the other being of a molecular size of approximately 3000 daltons.