Brebnor L, Phillips E, Balinsky J B
Enzyme. 1981;26(5):265-70. doi: 10.1159/000459189.
A single injection of glucagon increased the levels of all five urea cycle enzymes in 28-day-old rats, but had no significant effect in 35-day-old animals. Rats weaned onto diets varying in protein content showed rapid adaptation in the levels of carbamoylphosphate synthetase, which were complete 4 days after weaning. Induction of the enzyme by glucagon was independent of the diet. In animals subjected to a controlled feeding regime, no circadian variation in the levels of urea cycle enzymes could be observed. However, the inducibility of the enzyme by glucagon was greatest if the hormone was given near the beginning of the period of darkness and feeding.
单次注射胰高血糖素可提高28日龄大鼠体内所有五种尿素循环酶的水平，但对35日龄动物无显著影响。断奶后食用蛋白质含量不同日粮的大鼠，其氨甲酰磷酸合成酶水平迅速适应，断奶4天后即完全适应。胰高血糖素对该酶的诱导作用与日粮无关。在采用控制饲喂方案的动物中，未观察到尿素循环酶水平的昼夜变化。然而，如果在黑暗期和饲喂期开始时附近给予该激素，胰高血糖素对该酶的诱导作用最强。
