The Effects Of Glucose And Epinephrine On Pro- Liferation, Differentiation And Transcription Factor Expression Of Rat Preadipocytes

Adipogenesis includes increase both in amount of and invome of adipocytes,which involves proliferation of preadipocytes,differentiation of peadipocytes into mature fat cell,and triglyceride synthesis.Adipogenesis is influenced with many factor,such as nutrients and hormones. Carbohy- drate is the main egergy source and lipogenic substrate for animals,and it and hormones regulate adipogenesis together through several signalling pathways .Thus,it is highly important to elucidate the effects of nutritions and hormones on adipogenesis ang molecular mechanism underlying these roles in cntrol of fat accumulation of an animal body.Healthy, disease-free, 20-day-aged, male SD rats were selected as experimental material in this paper. Rat preadipocytes were isolated and cultured in vitro to investigate the regulation of glucose and epinephrine on cell's proliferation and differentiation. Also studied the glucose and epinephrine on rat preadipocytes transcription factor expression. In order to further clarify the nutrition and hormones in the preadipocytes proliferation and differentiation of the mechanism provides a theoretical basis. The results are as follows.Described natural growth pattern by growth curve of rat preadipocytes,The results showed that rat preadipocytes growth in line with the general laws,glose relationship with the inoculum concentration.Because preadipocytes in a specific time period,growth rate with animals closely related to age and location.Analysis of glucose and epinephrine on rat preadipocytes proliferation. MTT results showed that, Compared with the control group,5-25mmol/L glucose of groups significantly enhanced the proliferation of preadipocytes, it is more obvious at the early stage of preadipocyte proliferation. 0.10-61.25μmol/L range, the inhibition decreased with the epinephrine concentration increased, especially with the concentrations of 0.10-2.50μmol/L epinephrine on the growth inhibition of preadipocyte (P<0.05), especially with the second day when epinephrine to achieve 12.50μmol/L. From the second to the eighth day is not significant when the epinephrine concentration of 61.25μmol/L(P>0.05).Study of glucose and epinephrine on rat preadipocytes differentiation. Extraction of oil red O staining results showed that especially with the concentrations of 5-20mmol/L glucose on rat preadipocytes differentiation in promoting compared with control group,no significant effect when the concentration of 25mmol/L(P>0.05).Especially with the concentrations of 0.10-61.25μmol/L epinephrine on inhibition rat preadipocytes differentiation compared with control group.No significant difference with 0.10-61.25μmol/L each group.Study of glucose and epinephrine on expression of rat preadipocytes CHREBP and SREBP-1c transcription regulatory factor.Compared with control group, especially with the concentrations of 5-20mmol/L glucose promote adipocyte transcription factor CHREBP mRNA expression (P<0.05),5-25mmol/L glucose promote adipocyte transcription factor SREBP-1c mRNA expression (P<0.05),no significant difference with 15-25mmol/L each group(P>0.05). Especially with the concentrations of 0.10-2.50μmol/L epinephrine inhibit adipocyte transcription factor CHREBP mRNA expression compared with control group(P<0.05), no significant difference with 12.25-61.25μmol/L each group(P> 0.05).Especially with the concentrations of 0.10-0.50μmol/L epinephrine inhibit adipocyte transcription factor SREBP-1c mRNA expression Compared with the other groups(P<0.05), no significant difference with 2.50-61.25μmol/L each group compared with control group (P>0.05).