Columbano A, Ledda-Columbano G M, Ennas M G, Curto M, De Montis M G, Roomi M W, Pani P, Sarma D S
Istituto di Farmacologia e Patologia Biochimica, Università di Cagliari, Italy.
Basic Appl Histochem. 1988;32(4):501-10.
The effect of a single administration of lead nitrate on the activity of gamma-glutamyltranspeptidase (gamma-GT), adenosine triphosphatase (ATPase), the placental form of glutathione S-transferase (GST-P) and adenylate cyclase (AC), four enzymes widely used as phenotypic markers for preneoplasia, was investigated in the liver of male Wistar rats. The results of the histochemical enzymatic staining indicated that an acute treatment with lead nitrate induces the activity of gamma-GT, mainly in the hepatocytes located around zone I of the liver acinus, with a maximum seen between 72-96 hours. On the other hand, the activity of ATPase was found to be severely inhibited at 2-3 days after treatment, as shown by a strong decrease in the staining of the bile canaliculi of zones II and III. Immunohistochemical analysis revealed that lead nitrate administration also resulted in the appearance in most of the hepatocytes of GST-P, an enzyme whose activity is almost undetectable in normal rat liver, but is elevated in preneoplastic liver lesions. Finally, lead nitrate treatment resulted in an inhibition of AC activity which was maximal after 24 hours.
研究了单次给予硝酸铅对γ-谷氨酰转肽酶（γ-GT）、三磷酸腺苷酶（ATPase）、谷胱甘肽S-转移酶胎盘型（GST-P）和腺苷酸环化酶（AC）活性的影响，这四种酶广泛用作肿瘤前病变的表型标志物，实验对象为雄性Wistar大鼠肝脏。组织化学酶染色结果表明，硝酸铅急性处理可诱导γ-GT活性，主要在肝腺泡I区周围的肝细胞中，在72 - 96小时达到最大值。另一方面，处理后2 - 3天发现ATPase活性受到严重抑制，表现为II区和III区胆小管染色明显减弱。免疫组织化学分析显示，给予硝酸铅还导致大多数肝细胞中出现GST-P，该酶在正常大鼠肝脏中的活性几乎无法检测到，但在肿瘤前肝脏病变中升高。最后，硝酸铅处理导致AC活性受到抑制，在24小时后达到最大抑制程度。
