Savouré N, Maudet M, Nicol M
Biochimie Médicale A, Faculté de Médecine, Rennes.
Int J Vitam Nutr Res. 1993;63(3):173-9.
The ODC activity, initial enzyme in the polyamines synthesis, was studied in the liver and lungs of Wistar rat under avitaminosis A. In the liver: ODC activity is decreased by vitamin A deficiency but partially recovered with retinol repletion during 2 weeks. An intraperitoneal injection of chloroform markedly stimulates the ODC activity, as in the deficient rat as in the normal animal; the response following stimulation is even relatively higher under avitaminosis A. The Km value of ODC increases in the deficiency; intermediate values are obtained in retinol repletion. However the chloroform injection has no effect on the Km values under any of the nutritional state. In the lungs: The baseline ODC activity is slightly decreased in the deficient animals. The chloroform stimulation induced relatively a moderate increase in the normal rat (2 fold over baseline level); it is more intense (4 fold) in deficient animal and the ODC activity is well above those of normally fed control in absolute value. As in the liver, the enzyme Km increases in avitaminosis A and a retinol repletion partially attenuates this influence. Here again, the chloroform stimulation has no effect on the Km values.
在维生素A缺乏的情况下，对Wistar大鼠的肝脏和肺中多胺合成的起始酶——鸟氨酸脱羧酶（ODC）活性进行了研究。在肝脏中：维生素A缺乏会降低ODC活性，但在补充视黄醇2周后会部分恢复。腹腔注射氯仿可显著刺激ODC活性，无论是在缺乏维生素A的大鼠还是正常动物中均如此；在维生素A缺乏的情况下，刺激后的反应甚至相对更高。ODC的米氏常数（Km）在缺乏维生素A时增加；补充视黄醇时会得到中间值。然而，在任何营养状态下，注射氯仿对Km值均无影响。在肺中：缺乏维生素A的动物中ODC的基础活性略有降低。氯仿刺激在正常大鼠中引起相对适度的增加（比基础水平高2倍）；在缺乏维生素A的动物中更为强烈（高4倍），且ODC活性在绝对值上远高于正常喂养的对照动物。与肝脏中一样，维生素A缺乏时酶的Km增加，补充视黄醇可部分减弱这种影响。同样，氯仿刺激对Km值没有影响。
