Wanscher B, Almdal T P, Vilstrup H
Division of Hepatology, Rigshospitalet, Copenhagen, Denmark.
Horm Metab Res. 1989 Jun;21(6):313-6. doi: 10.1055/s-2007-1009223.
The effect of depletion of glucocorticoids on the dynamics of hepatic amino-N conversion was examined 2 and 7 days after adrenalectomy in a total of 22 rats substituted by adrenaline. The capacity of urea synthesis was studied by infusion of alanine under steady state conditions with arterial concentrations of alanine between 7.3 and 11.6 mmol/l. The animals were nephrectomized and the capacity was calculated as accumulation of urea in total body water corrected for intestinal hydrolysis. Adrenalectomy reduced the capacity of urea synthesis to 55% of the capacity for control rats and reduced the alanine metabolic rate to 60%. In control rats the urea synthesis exceeded the alanine infusion by indicating an extrahepatic tissue release of amino acids. This difference disappeared after adrenalectomy. The body weight and food intake did not change during the study period. Thus lack of glucocorticoids influences the in vivo nitrogen economy both by decreasing the liver function as to conversion of amino-nitrogen and by decreasing release of tissue amino-nitrogen.
在总共22只用肾上腺素替代的大鼠中，于肾上腺切除术后2天和7天，研究了糖皮质激素缺乏对肝脏氨基氮转化动力学的影响。在稳态条件下，通过输注丙氨酸，使动脉血丙氨酸浓度维持在7.3至11.6 mmol/l，来研究尿素合成能力。对动物进行肾切除，并将尿素合成能力计算为经肠道水解校正后的全身水中尿素的积累量。肾上腺切除术后，尿素合成能力降至对照大鼠的55%，丙氨酸代谢率降至60%。在对照大鼠中，尿素合成超过丙氨酸输注量，表明肝外组织释放氨基酸。肾上腺切除术后这种差异消失。在研究期间，体重和食物摄入量未发生变化。因此，糖皮质激素缺乏通过降低肝脏对氨基氮的转化功能以及减少组织氨基氮的释放，影响体内氮代谢。
