Hormonal regulation of lipogenesis in cultured adipose tissue from perinatal and month-old goats

Abstract

Perinatal (1–2 days old) and month-old (24–32 days old) male goats were used to investigate the effect of age and chronic culture (24 h) of perirenal and omental adipose tissue explants in the presence of insulin, cortisol and recombinant bovine somatotrophin (bGH), alone or in different combinations, on lipogenic responses in the absence and in the presence of catecholamines in acute incubations (2 h). Addition of insulin alone or bGH alone or insulin plus bGH had no effect on the rate of fatty acid synthesis in tissues of both groups. The presence of cortisol alone decreased ( P<0.05) and the combination of insulin plus cortisol increased ( P<0.05) lipogenesis in perirenal adipose tissue explants from month-old goats. No such effects of these hormonal combinations were noted in omental adipose tissue from perinatal and month-old goats or in perirenal adipose tissue from perinatal goats. When perirenal adipose tissue explants from month-old goats were cultured in the presence of insulin plus cortisol plus bGH the rates of lipogenesis were lower ( P<0.05) than those in cultures with insulin plus cortisol. Isoprenaline (Iso), but not noradrenaline (Ne), inhibited lipogenesis in freshly prepared adipose tissue explants; however, when maintained in tissue culture for 24 h, a response to Ne was induced. In cultured perirenal adipose tissue explants of both perinatal and month-old goats, the mean values of fatty acid synthesis were decreased ( P<0.05) by Ne and Iso: Ne and Iso were equally effective. However, in cultured omental adipose tissue explants, Iso was more effective than Ne.