胰岛素、胰高血糖素对体外培养犊牛肝细胞CPT-Ⅰ和CPT-ⅡmRNA表达的影响

Effects of insulin and glucagons on expression of CPT-Ⅰ and CPT-Ⅱ mRNA in primary cultured bovine hepatocytes in vitro

体外原代培养犊牛肝细胞,添加不同浓度的胰岛素(insulin,INS)(0、1、10、100、1 000nmol/L)和胰高血糖素(glucagon,GLN)(0、1、10、100、1 000nmol/L),每个处理做3个重复,分别培养1h后,提取总RNA。实时荧光定量PCR(qRT-PCR)的方法,检测肉碱棕榈酰转移酶Ⅰ(carnitine palmitoyl transferase,CPT-Ⅰ)和肉碱棕榈酸转移酶Ⅱ(carnitine palmitoyl transferase,CPT-Ⅱ)mRNA表达的变化。结果显示,随着培养液中INS含量的升高,肝细胞中CPT-ⅠmRNA和CPT-ⅡmRNA的表达量逐渐降低,呈现一定的剂量依赖性。随着培养液中GLN含量的升高,肝细胞中CPT-ⅠmRNA和CPT-ⅡmRNA的表达量均升高,呈现一定的剂量依赖性,且当GLN的添加浓度高于100nmol/L时,CPT-ⅠmRNA和CPT-ⅡmRNA的表达量显著升高(P<0.01)。结果表明,INS可在一定程度上抑制脂氧化关键酶的表达,GLN可显著促进脂氧化关键酶的表达。

INS and GLN were added to the media with the final concentrations of 0,1,10,100, 1 000 nmol/L,respectively. After 1-hour culture, hepatocytes were collected and total RNA was extracted. The expression levels of carnitine palmitoyl transferase-I （CPT-Ⅰ ） and carnitine palmitoyl transferase- Ⅱ （CPT Ⅱ ） mRNA were determined by using fluorescent quantitative real time PCR （qRT-PCR）. The present results showed that the expression levels of CPT-Ⅰ and CPT- Ⅲ decreased in a dose-dependent manner after 1 h INS-treated compared with untreated （UT） groups,but there was no statistical significance. The expression levels of CPT-Ⅰ and CPT-Ⅱ in- creased in a dose-dependent manner after 1 h GLN-treated when gradually increased glucagon in the culture media and were significantly higher when the concentrations of GLN added in the media exceed 100 nmol/L. In conclusion, the results of this study demonstrated that the expression of the key enzymes of lipid oxidation were inhibited by INS and were promoted significantly by GLN.