AJP - Gastrointestinal and Liver Physiology, Vol 246, Issue 1 96-G99, Copyright © 1984 by American Physiological Society
Insulinlike growth factors bind to specific receptors in isolated pancreatic acini
J. A. Williams, A. Bailey, R. Humbel and I. D. Goldfine
Recently we have demonstrated the existence of specific receptors for
insulin on pancreatic acini. Employing 125I-labeled insulinlike growth
factors (IGFs) and insulin, we report the existence of distinct receptors
for IGF-I and IGF-II on mouse pancreatic acini. Insulin competes with
125I-IGF-I with 1,000-fold less potency. By contrast, insulin increases the
binding of 125I-IGF-II to its receptor. IGF in turn inhibits 125I-insulin
binding to its receptor but with 250-fold less potency. Thus, distinct
receptors exist on acini for IGF-I, IGF-II, and insulin. Moreover, IGF,
like insulin, stimulates sugar transport by acini. The mechanism of IGF
stimulation may be similar to insulin, as the effect of maximal
concentrations of the two peptides when added together is not additive.
These results raise the possibility, therefore, that IGFs may be a new
class of physiological regulators of pancreatic acinar cell function.
