Husson A, Vaillant R
Endocrinology. 1982 Jan;110(1):227-32. doi: 10.1210/endo-110-1-227.
In the present study we examined the in vivo effects of glucocorticosteroids and glucagon on the developmental formation of the individual urea cycle enzymes argininosuccinate synthetase, argininosuccinase, and arginase during the late fetal period. In particular, addition of exogenous glucagon caused a rise in argininosuccinase and arginase activities in the livers of rat fetuses at term but not at earlier stages. Glucagon produced a rise in argininosuccinase activity earlier if fetuses were previously treated with cortisol. When fetuses were deprived of corticosteroid (hypophysectomy in utero), glucagon no longer promoted the argninosuccinase activity, indicating that adrenal glucocorticoids are required for normal enhancement of the enzyme activity by glucagon. Dibutyryl cAMP was still effective in hypophysectomized fetuses. Results obtained by injected combinations of inducers indicated that a glucocorticosteroid-glucagon interaction might be involved in the regulation of argininosuccinate synthetase and argininosuccinase. No synergistic action was found on arginase activity in vivo.
在本研究中，我们检测了糖皮质激素和胰高血糖素在胎儿后期对个体尿素循环酶精氨琥珀酸合成酶、精氨琥珀酸裂解酶和精氨酸酶发育形成的体内效应。特别地，添加外源性胰高血糖素会使足月大鼠胎儿肝脏中的精氨琥珀酸裂解酶和精氨酸酶活性升高，但在更早阶段则不会。如果胎儿先前用皮质醇处理过，胰高血糖素会更早地使精氨琥珀酸裂解酶活性升高。当胎儿缺乏皮质类固醇（子宫内垂体切除）时，胰高血糖素不再促进精氨琥珀酸裂解酶活性，这表明肾上腺糖皮质激素是胰高血糖素正常增强该酶活性所必需的。二丁酰环磷腺苷在垂体切除的胎儿中仍然有效。通过注射诱导剂组合获得的结果表明，糖皮质激素 - 胰高血糖素相互作用可能参与精氨琥珀酸合成酶和精氨琥珀酸裂解酶的调节。在体内未发现对精氨酸酶活性有协同作用。
