AJP - Endocrinology and Metabolism, Vol 248, Issue 3 304-E308, Copyright © 1985 by American Physiological Society
Enhanced intestinal insulinotropic effect in streptozotocin-diabetic rats
T. Ikeda, O. Mokuda, S. Kuno, Y. Tokumori, M. Tominaga and H. Mashiba
To study the intestinal insulinotropic effects in the diabetic state, an
investigation was made into the release of insulin from isolated rat
pancreas perfused with portal venous effluent (PVE) obtained from the
isolated perfused intestine of streptozotocin-induced diabetic rats. Rat
intestine was perfused with Krebs-Ringer bicarbonate medium for 1 h, and
the PVE was collected from both untreated and glucose-treated intestines of
control and diabetic rats. The PVE, after adjusting its glucose
concentration to the desired level, was used as the perfusing medium for
the pancreas of a different rat. Glucose concentration in the perfusion
medium was maintained at 5.5 mM for 20 min and at 16.7 mM for the next 30
min. Insulin output from pancreas perfused with PVE from untreated
intestine of diabetic rats (252 +/- 45 ng/30 min, mean +/- SD) was similar
to that of controls (269 +/- 72 ng/30 min). Pancreatic insulin output with
PVE from glucose-treated intestine of diabetic rats (579 +/- 100 ng/30 min)
was significantly greater compared with either that using PVE from
untreated intestine of diabetic rats (P less than 0.01) or that from
glucose-treated intestine of control rats (368 +/- 57 ng/30 min) (P less
than 0.02). These results indicate that the insulinotropic effect is
markedly enhanced in streptozotocin-induced diabetic rats.
