AJP - Endocrinology and Metabolism, Vol 244, Issue 3 209-E215, Copyright © 1983 by American Physiological Society
Insulin and gastric inhibitory polypeptide secretion in young milk-fed and adult goats
K. J. Nilssen, K. Hove and R. Jorde
Plasma concentrations of glucose, immunoreactive insulin (IRI), and
immunoreactive gastric inhibitory polypeptide (IR-GIP) were studied in six
adult and five young milk-fed goats after intravenous or intraduodenal
infusions of glucose. Glucose concentrations after intraduodenal infusions
were elevated from 3.5 to 4.7 mmol/liter on the average in adult and from 4
to 7 mmol/liter in young goats. Intravenous infusions were given at rates
adjusted to mimic very closely the plasma glucose curves after
intraduodenal infusions. Plasma IRI increased from 250 to 600 pmol/liter in
adult and from 180 to 500-600 pmol/liter in young goats, but no significant
differences were observed between intravenous and intraduodenal infusions.
Duodenal infusions of glucose did not stimulate the release of IR-GIP in
adult or young goats. It is concluded that the goat is lacking the incretin
system for rapid disposal of oral glucose loads and that IR-GIP does not
participate in regulation of glucose-stimulated insulin release in this
species.
