Karvonen E, Pösö H
Biochim Biophys Acta. 1984 Dec 7;791(2):239-43. doi: 10.1016/0167-4838(84)90014-1.
The activities of ornithine decarboxylase and spermidine N1-acetyltransferase started to rise in normal rat liver 4 h after the intraperitoneal injection of methylglyoxal bis(guanylhydrazone) (MGBG; 80 mg/kg). Ornithine decarboxylase had its greatest activity 24 h after a single injection of MGBG and the acetyltransferase peaked 8 h after the injection. Measurement of the apparent half-life of ornithine decarboxylase after MGBG treatment revealed a clear decrease in the decay rate of the enzyme in both normal and regenerating rat liver. MGBG slowed the decay of the transferase also in normal rat liver, as well as inhibiting its activity in vitro. The stabilization by MGBG of these two short-lived proteins involved in metabolism of polyamines should lead to their accumulation in liver, thus explaining their increased activities. In the case of ornithine decarboxylase, studies with a specific antibody against mouse kidney ornithine decarboxylase showed that the rise in ornithine decarboxylase activity after MGBG application was not due to the appearance of an immunologically different isozyme.
腹腔注射双（胍基腙）甲基乙二醛（MGBG；80毫克/千克）后4小时，正常大鼠肝脏中的鸟氨酸脱羧酶和亚精胺N1 - 乙酰转移酶活性开始升高。单次注射MGBG后24小时，鸟氨酸脱羧酶活性达到最高，而乙酰转移酶在注射后8小时达到峰值。测量MGBG处理后鸟氨酸脱羧酶的表观半衰期发现，正常和再生大鼠肝脏中该酶的衰减速率均明显降低。MGBG在正常大鼠肝脏中也减缓了转移酶的衰减，并在体外抑制其活性。MGBG对这两种参与多胺代谢的短寿命蛋白质的稳定作用应导致它们在肝脏中积累，从而解释了它们活性的增加。就鸟氨酸脱羧酶而言，用针对小鼠肾脏鸟氨酸脱羧酶的特异性抗体进行的研究表明，应用MGBG后鸟氨酸脱羧酶活性的升高并非由于出现了免疫上不同的同工酶。
