AJP - Regulatory, Integrative and Comparative Physiology, Vol 263, Issue 4 782-R784, Copyright © 1992 by American Physiological Society
Early insulin response after food intake in geese
H. Karmann, N. Rideau, T. Zorn, A. Malan and Y. Le Maho
Centre d'Ecologie et Physiologie Energetique, l'Universite Louis Pasteur, Strasbourg, France.
Plasma glucose and insulin levels were measured in chronically
catheterized, freely moving, undisturbed geese, which were offered a free
standard meal after an overnight fast. The insulin level markedly rose
within the first minute after the start of food ingestion, whereas plasma
glucose did not increase. This early insulin response was not correlated
with the size of the meal. In contrast, both postabsorptive insulin
response and plasma glucose changes were dependent on meal size. When a
small amount of food (2-6 g) was eaten, insulin returned to basal level
within 30 min, whereas plasma glucose remained unchanged. Larger meals
(15-20 g) maintained plasma insulin at a higher level and induced a
sustained rise of plasma glucose. These results indicate that there is a
cephalic phase of insulin secretion at the beginning of the meal in birds
as previously described in mammals.
