اثرات متاپروترونول (محرك بتاآدرنرژيك ) بر بافت چربي ، هورمون و متابوليت هاي خون ميش مغاني

Effects of metaproterenol (a beta-adrenergic agonist) on adipose tissue cellularity, hormones and metabolites of Moghani ewes

Beta-adrenergic agonists have been shown to decrease fat contents of the sheep carcass. The objective of this study was to evaluate the effects of metaproterenol (a beta-adrenergic-agonists) on adipose tissue cellularity, hormones and metabolites of ewes. Forty-five Moghani ewes were allocated to five treatments (groups) in a complete randomized design for three months. In the first month, ration (12.14 MJ/kg.DM) was similar for four groups and the fifth group was fed with low energy ration (10.71 MJ/kg.DM). After 30 days, metaproterenol was added to the ration each one with three levels of 5, 10 and 20 mg/kg.DM. Blood samples were collected on 30th, 60th and 90th days for determination of insulin, T4, triglyceride, cholesterol, HDL and LDL. Adipose tissue samples of fat-tail were obtained after slaughtering the animals. Metaproterenol and low energy ration resulted in lower adipocyte mean diameter (p<0.01). Plasma insulin concentration was lower for ewes receiving the low dose of metaproterenol (5 mg/kg.DM). In the second month, T4 concentration was increased by middle dose (10 mg/kg.DM) of beta-agonist but in the next month this effect disappeared (p<0.05). Metaproterenol and low energy diet had significant effect on plasma triglyceride, cholesterol, HDL and LDL concentration. The results indicated that metaproterenol had significant effect on lipid metabolism of Moghani ewes and it reduced the lipid content of the fat-tail.