Laila Lamri, Zineb Choukairi, Tahar Hazzaz, Khalid Halim, Taoufiq Fechtali
Abstract: The aim of the present study was to understand the effect of cold and i.c.v glucagon administration on plasma catecholamine. Cold exposure (+4C) induces a 42 % increase of arteriel plasma norepinephrine (NE) in thermoneutral (TN) ducklings. Thus, cold has a stimulatory effect on the sympathetic nervous system (SNS). 15min after i.c.v glucagon injection plasma epinephrine (E) increase in TN ducklings, (74 %) whereas NE concentration decrease (23 %) only in TN. Plasma NE remained in glucagon treated (GT). Injection of glucagon causes a decrease in heart rate (HR) in TN duckling whereas it has no effect on GT ducklings. In conclusion, large increase in E levels in TN ducklings may be due to a massive release of adrenal catecholamine in response to cold and i.c.v glucagon administration. Treatment with glucagon twice daily rendered ducks possibly insensitive to the effect of i.c.v glucagon injection.
Keywords: Cold, icv Glucagon, Norepinephrine, Thermoneutral, Sympathetic Nervous System