皮质酮对大鼠再生肝细胞鸟氨酸脱羧酶活性及其基因表达的影响  

Effect of corticosterone on the activity and gene expression of ornithine decarboxylase in rat regenerating hepatocytes

作　　者：宁黔冀[1] 杨洪[1] 李恩中[1] 李超堃[1] 徐存拴 

机构地区：[1]河南师范大学生命科学学院,河南新乡453002

出　　处：《动物学报》2004年第5期778-783,共6页ACTA ZOOLOGICA SINICA

基　　金：河南省自然科学基金 (No .2 0 0 1180 0 0 0 9);河南省高校青年骨干教师资助计划;河南省重点学科资助~~

摘　　要：采用高效液相色谱和原位杂交技术研究了皮质酮对大鼠再生肝细胞鸟氨酸脱羧酶 (ODC)活性及ODCmRNA表达的影响。结果显示 ,大鼠完整肝脏中ODC水平较低 ,2 / 3肝切除 (PH)后 3h ,不同处理组ODC活性开始升高 ,6h达到最高值 ,其中 ,去肾上腺 +NaCl组和糖皮质激素受体拮抗剂RU4 86处理组的酶活性高于对照组 (去肾上腺假手术组 ) ,而去肾上腺 +皮质酮处理组的酶活性低于对照组 ,36h恢复到肝切除前水平 ;完整肝脏的ODCmRNA水平极低 ,PH后表达量迅速增加 ,5h达到最大值 ,不同处理组mRNA水平的高低顺序与酶活性一致 ,12h降至肝切除前水平 ;在PH前 12h给大鼠注射RU4 86 (10mg/kg体重 ) ,取得了与去肾上腺 +NaCl处理鼠相似的结果。以上结果表明 ,在PH诱导的再生肝细胞中 ,ODCmRNA表达量的增加和 /或减少是造成ODC活性改变的原因之一 ,皮质酮对ODC活性及其mRNA的表达具有抑制作用 ,主要表现在肝再生的早期 。The effects of corticosterone on ornithine decarboxylase (ODC) activity and its mRNA expression of the regenerating hepatocytes in sham-operated and adrenalectomized male Sprague-Dawley rats were investigated using reverse-phase high-performance liquid chromatography and in situ hybridization assays. The results showed that ODC activities and mRNA levels increased rapidly in regenerating livers induced by partial hepatectomy (PH), and respectively peaked 6h and 5 h after PH , and restored to the pre-PH levels at 36 h and 12 h in all groups. The enzyme activities at 6 h and ODC mRNA levels at 5 h in adrenalectomized rats and RU486-treated rats were higher than those of control (sham-adrenalectomized) rats. Meanwhile the lowest ODC activities and mRNA levels were detected in adrenalectomized rats treated with corticosterone. Ru486, the glucocorticoid receptor antagonist , was given subcutaneously at a dose of 10 mg/kg body weight 12 h before PH. The similar results were observed in the adrenalectomized rats. These results suggested that the changes in the level of ODC mRNA expression contributed partly to the changes of ODC activity. ODC activity and ODC mRNA expression in regenerating hepatocytes induced by PH were inhibited by corticosterone likely via the binding of corticosterone to its receptors only in early stage of liver regeneration.

关 键 词：皮质酮 ODC 大鼠 肝细胞 肝切除 肾上腺 对照组 MRNA水平 动物学 酶活性 

分 类 号：Q952[生物学—动物学]