Sernia C, McDonald I R
J Endocrinol. 1977 Nov;75(2):261-9. doi: 10.1677/joe.0.0750261.
The effects of injections of cortisol, corticosterone and ACTH on indices of carbohydrate, fat and protein metabolism were investigated in the conscious echidna, Tachyglossus aculeatus. Intravenous infusion of cortisol and corticosterone for 2 h at rates of 3 and 30 microgram/kg/h respectively did not cause significant changes in the plasma concentrations of glucose, urea or amino acids during a 12.5 h observation period. In contrast, a dose-related increase in plasma free fatty acid (FFA) concentration was observed. Infusion of synthetic ACTH at 2 i.u./kg/h for 2 h caused a minor, short-lived increase in FFA concentration. Daily i.m. injections of 0.2 mg cortisol or corticosterone acetates/kg, which raised plasma total corticosteroid concentrations to levels characteristic of maximal ACTH stimulation, did not cause glycosuria nor was there any change in body weight, nitrogen intake or urinary nitrogen excretion. However, there was a minor, but significant, increase in plasma glucose concentration. The liver glycogen content of 24 h fasted, corticosteroid-treated animals was similar to that of fasted control animals. It is concluded that cortisol, corticosterone and ACTH have only minor effects on carbohydrate and protein metabolism and that the main action of these hormones may be to mobilize fat reserves.
在清醒的针鼹（Tachyglossus aculeatus）身上，研究了注射皮质醇、皮质酮和促肾上腺皮质激素（ACTH）对碳水化合物、脂肪和蛋白质代谢指标的影响。分别以3微克/千克/小时和30微克/千克/小时的速率静脉输注皮质醇和皮质酮2小时，在12.5小时的观察期内，血浆葡萄糖、尿素或氨基酸浓度未出现显著变化。相比之下，观察到血浆游离脂肪酸（FFA）浓度呈剂量相关增加。以2国际单位/千克/小时的速率输注合成ACTH 2小时，导致FFA浓度出现轻微、短暂的增加。每天肌肉注射0.2毫克醋酸皮质醇或醋酸皮质酮/千克，使血浆总皮质类固醇浓度升至最大ACTH刺激时的特征水平，未引起糖尿，体重、氮摄入量或尿氮排泄也无变化。然而，血浆葡萄糖浓度有轻微但显著的增加。禁食24小时且接受皮质类固醇治疗的动物肝脏糖原含量与禁食对照动物相似。结论是，皮质醇、皮质酮和ACTH对碳水化合物和蛋白质代谢仅有轻微影响，这些激素的主要作用可能是动员脂肪储备。
