AJP - Endocrinology and Metabolism, Vol 241, Issue 3 215-E220, Copyright © 1981 by American Physiological Society
Effects of starvation and obesity on somatostatin, insulin, and glucagon release from an isolated perfused organ system
G. Boden, C. A. Baile, C. L. McLaughlin and F. M. Matschinsky
We have studied the effects of starvation and of obesity on somatostatin,
insulin, and glucagon release from an isolated perfused organ system in fed
and 3- and 5-day fasted Holtzman rats and in obese (fa/fa) and lean (Fa/?)
Zucker rats. Fasting for 3 days significantly decreased basal (-71%) and
amino acid-stimulated (-62%) somatostatin output. After 5 days of
starvation, there was a significant increase over the 3-day level in
somatostatin output stimulated by amino acid plus glucose (+540%) and by
amino acids plus tolbutamide (+238%). Three and five days of starvation
severely depressed insulin output while having no statistically significant
effects on glucagon secretion. Somatostatin output from obese Zucker rats
was significantly greater than that from lean controls in response to amino
acids (41.2 +/- 13.2 vs. 16.3 +/- 10.3 ng/25 min, P less than 0.05).
Insulin output was greatly increased from obese compared to lean Zucker
rats, whereas there were no statistically significant differences in
glucagon output. These data show that fasting decreases and obesity
increases both somatostatin and insulin release. They suggest that altered
stimulation by nutrients was primarily responsible for changes in
somatostatin and insulin release observed in starving and obese rats.
