Effect of Somatostatin in the Syrian Hamster Bearing a Transplantable Islet-Cell Tumor[*]

Abstract

The influence of somatostatin (SRIF) on blood glucose, plasma insulin and plasma glucagon was studied in hamsters bearing a transplantable islet-cell tumor secreting insulin and glucagon as well as in normal controls.

Fed anesthetized animals were infused intraperitoneally either at a dose of 10 µg in 15 min or of 150 µg in 30 min, and intravenously at a dose of 250 µg in 30 min. Blood was withdrawn from the jugular vein before and after infusion. Before the infusions, tumor bearing animals (TB) had lower blood glucose, markedly elevated plasma glucagon and slightly lower plasma insulin by comparison with normal hamsters (N).

Both doses of somatostatin infused by the intraperitoneal route produced a slight but significant hypoglycemia in TB hamsters but not in normals. Ten µg SRIF did not affect insulin and plasma glucagon levels whereas 150 µg SRIF significantly depressed plasma insulin in both types of hamsters (N and TB). This latter dose of SRIF decreased plasma glucagon in normal but not in tumor-bearing hamsters. Intravenous infusion of 250 µg SRIF did not reduce the hyperglucagonemia of TB hamsters either.

These results indicate that somatostatin does not reduce the hyperglucagonemia due to the transplantable islet-cell tumor but nevertheless decreases blood glucose and plasma insulin.

Key words

Somatostatin (SRIF) - Syrian Hamster - Transplantable Islet-Cell Tumor - Plasma Insulin - Plasma Glucagon - Blood Glucose

1 Presented in part at the 12th Meeting of the European Diabetes Association, Helsinki, Sept. 1976.

1 Presented in part at the 12th Meeting of the European Diabetes Association, Helsinki, Sept. 1976.

2 Chercheur Qualifié of the Fonds National Belge de la Recherche Scientifique.