AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 4 393-R401, Copyright © 1985 by American Physiological Society
Fat and lean chickens: prefattening period and in vivo sensitivity to insulin, atropine, and propranolol
J. Simon and B. Leclercq
Fat (FL) or lean (LL) chickens have been obtained by divergent selection.
In previous studies, FL chickens were consistently hypoglycemic (slightly)
and had high plasma levels of insulin in response to glucose or refeeding
from 5 to 8 wk of age. In these, at 12-13 days of age before any difference
in fattening can be demonstrated, FL chickens exhibit a better glucose
tolerance pattern and enhanced glucose-induced insulin levels but normal
insulin levels during refeeding. Plasma levels of alpha-NH2 nonprotein
nitrogen, uric acid, free fatty acids, and potassium were neither
consistent nor significantly different between lines. Atropine, at high
dose, blocked the absorption of glucose and at low dose had no major effect
on glucose-induced insulin release in either line. At 8 wk, sensitivity to
and disappearance of exogenous insulin were normal in FL birds. Propranolol
slightly decreased plasma glucose and inhibited the hypokalemic effect of
exogenous insulin to the same extent in both lines. Cerebrospinal fluid
glucose level and liver glycogen content were similar in both lines in the
fasting or the fed state, but liver glycogen was restored faster after
refeeding in the FL, at least in older birds.
