A POSSIBLE INTERACTION BETWEEN CATECHOLAMINE AND GLUCAGON TO INDUCED THERMOGENESIS IN DUCKLING (CARINA MOSCHATA): A HPLC STUDY
M. SLIMANI 1, S. EL ANTRI 1, M. EL HADDAD 2, H. BARRÉ 3, T. FECHTALI 1* (1)LABORATOIRE DE PHYSIOLOGIE ET ECOPHYSIOLOGIE; FACULTÉ DES SCIENCES ET TECHNIQUES, B.P: 146, 20800 MOHAMMÉDIA MOROCCO (2)FACULTÉ POLYDISCIPLINAIRE, DÉPPARTEMENT SCIENCES DE LA MATRICCE, UNIVERSITÉ CADI AYYAD, BP 4162, 46000 SAFI, MOROCCO (3)PHYSIOLOGIE-
The aim of the present study was to investigate whether the thermoregulation in avian results from a direct action of glucagon or requires the participation of other agents such as catecholamines. We focused our study on the effects of central glucagon on plasma catecholamine and heart rate on thermoneutral (TN) and glucagon treated (GT) ducklings in cold environment. Our results showed that cold exposure (4 °C) induced an increase of circulating Norepinephrine (NE) in TN (42%) but not significantly in GT, while Epinephrine (E) decreased only in TN (-45%). After glucagon injection, we found that circulating E increase in TN 280%, whereas NE concentrations decreased only in thermoneutral ducklings (-23%). Central glucagon injection causes a decrease in heart rate in thermoneutral duckling whereas it has no effect on glucagon treated ducklings. The increase in E levels in thermoneutral ducklings may be due to a massive release of adrenal catecholamine in response to cold. Treatment with glucagon twice daily rendered probably ducks insensitive to the effect of intracerebroventricular (ICV) glucagon injection.
