AJP - Endocrinology and Metabolism, Vol 246, Issue 6 506-E509, Copyright © 1984 by American Physiological Society
Difference in glucose dependency of insulin and somatostatin release
P. Ronner and A. Scarpa
The splenic Brockmann body of channel catfish (Ictalurus punctatus) was
isolated and perfused in vitro. It has been shown previously that the
hormone release from the catfish pancreas in response to various stimuli
resembled that of a mammalian pancreas. The release of insulin and
somatostatin was measured at various concentrations of glucose in the
perfusate, and the corresponding dose-response curves were derived. As in a
variety of mammalian pancreases, insulin release was stimulated
half-maximally at ca. 9 mM glucose. In contrast, half-maximal somatostatin
release occurred already at ca. 5 mM glucose. Although a comparable finding
with mammalian D cells has not yet been reported, histological and
physiological resemblances of the mammalian and the fish pancreas suggest
that mammalian D cells may also have a glucose sensitivity in the 5 mM
range.
