Effect of cimaterol on sheep adipose tissue lipid metabolism.
Effects of dietary cimaterol (5 mg/kg) on adipose tissue metabolism of wether lambs were studied. Lipogenesis, lipolysis, fatty acid composition and adipocyte size and number were measured. Cimaterol feeding increased lipogenesis; however, this effect was not statistically significant. Insulin (1,000 microU/ml) stimulated lipogenesis of adipose tissue from control sheep. However, this elevated rate was abolished by in vitro cimaterol. Insulin had no stimulatory effect on lipogenesis in cimaterol-fed sheep. Lipolysis was depressed by cimaterol feeding. However, 10(-4) M cimaterol stimulated lipolysis in the adipose tissue from both control and cimaterol-fed sheep. Insulin inhibited stimulated lipolysis in adipose tissue from control sheep but had no effect on the stimulated lipolysis in cimaterol-fed sheep. Mean adipocyte diameter was smaller (from 74 to 70 microns) and adipocyte size distribution also was changed in the cimaterol-fed sheep. Adipocyte number per gram of tissue was not affected by cimaterol. There was a significant increase in percentage of unsaturated fatty acids in adipose tissue from cimaterol-fed sheep. These results indicate that lipogenic and lipolytic responses to insulin and cimaterol in sheep adipose tissue were altered by cimaterol feeding. The carcass fat content decrease in cimaterol-fed sheep may be attributed to the reduction in adipocyte size.
D000273:Adipose Tissue / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D004983:Ethanolamines / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D050356:Lipid Metabolism; D008055:Lipids / Q000096:biosynthesis; D008066:Lipolysis / Q000187:drug effects*; D008297:Male; D012756:Sheep / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D007328:Insulin; D008055:Lipids; C047411:cimaterol