AJP - Endocrinology and Metabolism, Vol 251, Issue 1 86-E91, Copyright © 1986 by American Physiological Society
Effect of gestational hyperglycemia on insulin secretion in vivo and in vitro by fetal rat pancreas
M. T. Bihoreau, A. Ktorza, A. Kervran and L. Picon
The effects of gestational hyperglycemia on B-cell function were studied in
near-term fetuses from unrestrained pregnant rats made slightly or highly
hyperglycemic using continuous glucose infusion during the last week of
pregnancy. Pancreatic and plasma insulin and insulin secretion in vitro
were studied in the fetuses. Compared with controls, slightly hyperglycemic
fetuses showed increased pancreatic and plasma insulin concentrations and
similar insulin release in response to glucose in vitro. In highly
hyperglycemic fetuses, pancreatic and plasma insulin concentrations were
unchanged compared with controls, and insulin release in vitro was
insensitive to glucose and to the mixture glucose plus theophylline. These
results confirm that glucose is able to stimulate insulin secretion in
normal or slightly hyperglycemic fetuses and suggest that severe
hyperglycemia per se, without association of other metabolic disorders or
toxic injuries, profoundly alters the stimulus-secretion coupling of the
fetal rat B-cell.
