Abstract：Preadipocytes were obtained from newborn Chinese Holstein calves and induced differentiation for 9 days. The cells became larger and circular accompanied by the small lipid droplets confluenting into large ones and increased mRNA expression of PPAR-γ. At same time ,the expression of Pref-1 was decreased and cells differentiated ultimately into typical adipocytes. Using semi-quantitative RT-PCR method, 1 nmol/L insulin did not affect the expression adiponectin mRNA, but 10, 100 and 1000 nmol/L insulin decreased expression adiponectin mRNA 48.7%,61.4% and 61.9%, respectively (P<0.05). Meanwhile, 100 nmol/L insulin in time-dependent fashion inhibits expression adiponectin mRNA within 24 h. Furthermore, inhibition of PI3K/Akt with LY294002 reverses the inhibitory effect of insulin on adiponectin mRNA expression. These results suggest that insulin at least partially suppressed the expression of Adiponectin mRNA via the PI3K/Akt pathway.
