The preliminary study on the effects of growth hormone and insulin-like growth factor-I on -casein synthesis in bovine mammary epithelial cells invitro

摘要

The effects of growth hormone (GH) and insulin-like growth factor-I (IGF-I) on protein synthesis and gene expression of -casein in bovine mammary epithelial cell invitro were studied. The treatments were designed as follows: the growth medium without serum was set as the control group, while the treatments were medium supplemented with GH (100ng/ml), IGF-I (100ng/ml), and GH (100ng/ml)+IGF-I (100ng/ml). The quantity of -casein protein was measured by ELISA, and the -caseingene (CSN3) expression was examined by real-time quantitative PCR (RT-qPCR). Compared with the control group, all the experimental groups had greater (p0.05) expression of CSN3. The concentration of -casein followed a similar response as CSN3, but the difference between the treatments and the control was not statistically significant (p>0.05). Furthermore, no synergistic effect of GH and IGF-I was observed for both the -casein concentration and CSN3 expression. It is therefore concluded that GH or IGF-I can independently promote the expression of CSN3 in bovine mammary epithelial cells in vitro.