Abstract：Endocrine growth hormone (GH) combining with the growth hormone receptor (GHR) to form GH-GHR-IGF1 pathway, played crucial roles in animal growth. Insulin-like growth factor 1 (IGF1), a kind of regulating polypeptide, acted in animal development and physiological regulation. In this study, the effects of different ways and GH concentration on the expression of IGF1 were analyzed in chicken primary myoblast cells. It was benefit for us to determine the appropriate way and GH concentration to induce IGF1 expression, which laid the basis for further analyzing the regulatory mechanism of GH in muscle development. The chicken (Gallus gallus) primary myoblast cells were isolated and cultured by physical operations and differential adhension methods using chicken embryo hatching to 11 d. The different concentrations of GH (50, 100, 200 and 500 ng/mL) were added into the DuIbecco's modified eagIe's medium (DMEM) media with or without fetal bovine (Bos tarus) serum to culture the cells for 3 h. The cells were harvested and the total RNAs were isolated to analyze the expression of IGF1. Results indicated that chicken GH protein could induce the expression of IGF1 both in mRNA and protein levels. Chicken IGF1 were more highly expressed under the condition of serum starvation than that of serum culture at the same GH concentration. The expression of IGF1 reached the highest level when 200 ng/mL GH was added under the condition of serum starvation. It indicated that the best way to induce IGF1 expression was that adding 200 ng/mL GH into DMEM media after chicken primary myoblast cells were serum starvation for 10 h. The results provide the basic data for broiler muscle development and lays the basis for further studying the roles of GH-GHR-IGF1 pathway in myoblast cells proliferation and differentiation.
