Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 4, 1996
Publication Date: N/A
Interpretive Summary: In the past, studies to elucidate the role of hormones and other factors involved in regulating growth and metabolism in domestic poultry have employed hormones derived from mammalian sources because of the unavailability of avian hormones. It is well documented there are significant structural and amino acid compositional differences between mammalian protein hormones and their avian hormone counterparts. The pancreatic hormone glucagon plays a significant role in regulating carbohydrate and lipid metabolism in birds. This study was conducted to determine if avian glucagon was metabolized differently than porcine glucagon in turkey hens and to determine the metabolic response to both glucagons. It was determined that mammalian glucagons are metabolized in a similar manner to chicken glucagon when injected and that the metabolic response to both glucagons did not differ. This study will be of interest to other scientists.
The purpose of this study was to compare the metabolism (T1/2) of chicken and porcine glucagon in the turkey hen. Six hens each were infused with either porcine or chicken glucagon (16.6 ug/kg bwt). Blood samples were obtained at intervals pre- and post-infusion, and analyzed for glucagon, glucose, insulin, free fatty acids, thyroxine (T4) and triiodothyronine (T3). The half-life of porcine (4.5 min) and chicken glucagon (5.5 min) were similar. A 13 % increase in glucose concentrations occurred within 10 min and remained elevated (22%) for 2 hrs. A concomitant increase in insulin was noted, though not significant from pre-injection levels. A 50% increase in free fatty acids occurred in 2 min, reaching a zenith at 10-15 min post-treatment, and returned to baseline by 2 hrs. Significant (P<.05) decreases in the circulating concentrations of both thyroid hormones was observed within 5 to 10 min post-glucagon treatment, and remained suppressed for the duration of sampling. These data indicate that the biological effects of mammalian and avian glucagon are similar.