皮质酮对大鼠肝再生过程中鸟氨酸脱羧酶的抑制(英文)  

INHIBITION OF GLUCOCORTICOID ON ORNITHINE DECARBOXYLASE DURING RAT LIVER REGENERATION

作　　者：马建敏[1] 和俊涛[1] 索世英[1] 宁黔冀[1] 徐存栓 

机构地区：[1]河南师范大学生命科学学院 [2]省部共建细胞分化调控国家重点实验室,河南新乡453007

出　　处：《解剖学报》2008年第5期693-698,共6页Acta Anatomica Sinica

基　　金：National Natural Science Foundation of China(30340042)

摘　　要：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 The regulation of ornithine deearboxylase （ODC） gene expression and enzyme activity by eorticosterone, the main glucocorticoid in rat, during rat liver regeneration induced by partial hepatectomy （PH） was evaluated. Methods Bilateral adrenaleetomies （ADX） and sham-ADX were performed on ether-anesthetized rats 3 days before PH. Corticosterone in sesame oil was injected subcutaneously to adrenalectomied rats. ODC mRNA, ODC protein and enzyme activity were detected by RT-PCR, Western blotting and high performance liquid chromatography （HPLC）, respectively. Results The ODC mRNA levels, protein accumulation and enzyme activity were lower in the intact liver compared to the regenerating liver. After PH, mRNA levels were remarkably enhanced in all groups （ n = 6 in each group） and peaked at 5 hours post-PH. Till 7 hours, the contents in all groups from high to low were ADX group, control group （Sham-ADX group）, ADX treated with 10mg/kg and 40mg/kg body weight corticosterone group, respectively. ODC protein accumulation in ADX rats was higher than that in control rats （ n = 13, the same below）, but it decreased in treated （10mg/kg） rats until 24 hours post-PH, with a strong decline seen in 40mg/kg corticosterone-treated rats. ODC activity was rapidly promoted, and the highest levels were observed at 6 hours after PH in all groups （n = 6 in each group ）. After corticosterone treatment, the activities declined significantly at 6 hours post-PH, with the lowest value found in the 40mg/kg group. Conclusion Cortieosterone treatment results in dose-dependent decreases in ODC mRNA and enzyme protein both in the intact liver and the regenerating liver. The change in ODC activity is partially related to alterations of ODC mRNA and protein accumulation.

关 键 词：皮质酮 肝再生 鸟氨酸脱羧酶 RT-PCR Western BLOTTING 高效液相色谱法 大鼠 

分 类 号：Q71[生物学—分子生物学]