Abstract:

To investigate the effect of cAMP on fatty acid oxidation in skeletal muscle cells and elucidate the mechanism of the effect of cyclic AMP(cAMP) on fatty acid oxidation in skeletal muscle. Methods The primary muscle cells(PMC) and C2C12 cells were treated with α-MSH,cAMP analogs Bt2cAMP,8-BrcAMP and cAMP antagonist respectively,and they were divided into α-MSH group,cAMP agonists group,cAMP antagonist plus α-MSH group,and control group was set up at the same time.The fatty acid oxidation was measured by quantitating the production of 3H2O from (9,10 -3H) palmitate. Melanocortin receptor(MCR) subtypes in the muscle and C2C12 cells were measured by RT-PCR. Results The fatty acid oxidation was  significantly increased in  cAMP analogs group and α-MSH group   compared with  control group(P<0.05),and the fatty acid oxidation in  cAMP antagonist plus α-MSH group was significantly reduced  compared with  α-MSH group(P<0.05),and there was no significant difference compared with  control group(P>0.05). Conclusion α-MSH and cAMP analogs significantly increase the fatty acid oxidation,α-MSH might be binding with MCR and they increase fatty acid oxidation in skeletal muscle through cAMP signal transduction pathway.

Key words: cAMP, α-melanocyte stimulating hormone, fatty acid oxidation