链脲佐菌素对大鼠肝脏中酪氨酸转氨酶的诱导作用、NAD含量及5-甲基胞嘧啶含量的影响。

Influence of streptozotocin upon the induction of tyrosine aminotransferase, the content of NAD and of 5-methyl cytosine in rat liver.

作者信息

Kröger H, Grätz R, Grahn H, Wohlert H

出版信息

Int J Biochem. 1986;18(9):821-7. doi: 10.1016/0020-711x(86)90059-5.

Abstract

The antibiotic, streptozotocin, has carcinostatic, carcinogenic, and diabetogenic properties. Moreover, it is capable of inducing the enzyme tyrosine aminotransferase in a permanent line of rat liver cells. In the present publication, the effects of streptozotocin upon the induction of tyrosine aminotransferase, NAD synthesis, and methylation of DNA in different organs were analyzed in vivo. If administered alone, streptozotocin slightly induced tyrosine aminotransferase. The induction of tyrosine aminotransferase caused by tryptophan or nicotinamide was inhibited by streptozotocin. Streptozotocin reduced the NAD content of the liver. NAD synthesis induced by tryptophan was reduced by streptozotocin, while that induced by nicotinamide was enhanced. DNA methylation in the form of 5-methyl cytosine was not influenced by streptozotocin.

摘要

抗生素链脲佐菌素具有抑制肿瘤生长、致癌和致糖尿病的特性。此外，它能够在大鼠肝细胞的永久细胞系中诱导酪氨酸转氨酶。在本出版物中，在体内分析了链脲佐菌素对不同器官中酪氨酸转氨酶诱导、NAD合成和DNA甲基化的影响。单独给药时，链脲佐菌素轻微诱导酪氨酸转氨酶。链脲佐菌素抑制了色氨酸或烟酰胺引起的酪氨酸转氨酶诱导。链脲佐菌素降低了肝脏的NAD含量。色氨酸诱导的NAD合成被链脲佐菌素降低，而烟酰胺诱导的NAD合成则增强。5-甲基胞嘧啶形式的DNA甲基化不受链脲佐菌素的影响。