论文部分内容阅读
目的研究大鼠体内主要的糖皮质激素——皮质酮对部分肝切除(PH)诱导的再生肝鸟氨酸脱羧酶(ODC)基因表达及酶活性的影响。方法乙醚麻醉大鼠,于PH前3d行双侧肾上腺切除术及假手术,皮质酮悬浮于芝麻油中皮下注射去肾上腺鼠。用RT-PCR、Western blotting及高效液相色谱法(HPLC)分别测定ODC mRNA、ODC蛋白及酶活性。结果与再生肝相比,完整肝中ODC mRNA、蛋白及其酶活性水平较低。PH后所有组(每组n=6)中ODCmRNA水平均显著升高,5h达到峰值,7h前mRNA含量由高到低依次为去肾上腺组、去肾上腺假手术组(即对照组)、10和40mg/kg体重皮质酮处理组。去肾上腺组(n=13,下同)的ODC蛋白量高于对照组,10mg/kg体重皮质酮处理,在PH后0~24h下降,40mg/kg皮质酮处理组最低。PH后,所有组(每组n=6)ODC活性迅速升高,6h达到峰值;皮质酮处理后活性在6h下降显著,40mg/kg体重皮质酮处理组活性最低。结论皮质酮处理后,大鼠完整肝及再生肝中ODC mRNA及蛋白水平呈剂量依赖性下降;ODC活性变化的部分原因是由于ODC mRNA及其蛋白量的改变。
Objective To investigate the effect of corticosterone, a major glucocorticoid in rat, on gene expression and enzyme activity of ornithine decarboxylase (ODC) induced by partial hepatectomy (PH). Methods Rats were anesthetized with diethyl ether. Both sides of adrenalectomy and sham operation were performed on the third day before PH. Corticosterone was suspended in sesame oil and injected into the adrenal glands. ODC mRNA, ODC protein and enzyme activity were determined by RT-PCR, Western blotting and HPLC respectively. Results The level of ODC mRNA, protein and enzyme activity in intact liver was lower than that in regenerative liver. The ODCmRNA levels of all groups (n = 6 in each group) were significantly increased after PH and peaked at 5h. The mRNA levels in descending adrenal gland group (descending adrenal gland group, control group) 40mg / kg body weight corticosterone treatment group. The amount of ODC protein in the adrenal gland group (n = 13, the same below) was higher than that in the control group, and the dose of corticosterone at 10 mg / kg body weight decreased from 0 to 24 h after PH, and the lowest in 40 mg / kg corticosterone group. The ODC activity of all the groups (n = 6 in each group) rapidly increased after 6 h and reached its peak at 6 h. The activity of corticosterone decreased significantly at 6 h, and the activity of corticosterone at 40 mg / kg body weight was the lowest. Conclusions After corticosterone treatment, ODC mRNA and protein levels in intact liver and regenerated liver of rats decreased in a dose-dependent manner. The changes of ODC activity were partly attributed to the changes of ODC mRNA and its protein content.