Sakima N T, Breslow M J, Raff H, Traystman R J
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
Am J Physiol. 1991 Aug;261(2 Pt 2):H410-5. doi: 10.1152/ajpheart.1991.261.2.H410.
To determine whether adrenal O2 consumption and cortical blood flow (CBF) increase during stimulation of cortical secretory activity, exogenous adrenocorticotrophic hormone (ACTH) was infused at 0, 2, and 10 ng.kg-1.min-1 (groups 1, 2, and 3, respectively) into dexamethasone-pretreated, pentobarbital-fentanyl-anesthetized, ventilated dogs. ACTH levels of approximately 20, 100, and 500 pg/ml were obtained in groups 1, 2, and 3, respectively. Cortisol secretion increased after 20 min in groups 2 and 3 (from 0.016 +/- 0.004 to 2.25 +/- 1.36 and from 0.02 +/- 0.01 to 5.32 +/- 1.23 microgram.min-1.g cortex-1, respectively) while adenosine 3',5'-cyclic monophosphate (cAMP) secretion increased after 20 min only in group 3 (from 5.7 +/- 2.8 to 61.3 +/- 18.6 micrograms.min-1.g cortex-1). Whole adrenal gland O2 consumption increased after 20 min in group 3 animals (from 0.89 +/- 0.16 to 1.77 +/- 0.27 ml O2.min-1.100 g tissue-1) but not in the other two groups. CBF measured with radiolabeled microspheres was unaffected by ACTH infusion while O2 extraction increased from a baseline of 5.9 +/- 1.4 to 13.0 +/- 2.4% after 30 min in group 3. These data demonstrate that in anesthetized dogs increases in adrenal cortical secretory activity are associated with increases in O2 consumption, and this increase in O2 consumption is met by increasing O2 extraction, not by increasing cortical blood flow.
为了确定在刺激皮质分泌活动期间肾上腺的氧消耗和皮质血流量（CBF）是否增加，将外源性促肾上腺皮质激素（ACTH）分别以0、2和10 ng·kg-1·min-1（分别为第1、2和3组）的剂量注入经地塞米松预处理、戊巴比妥-芬太尼麻醉、机械通气的犬体内。第1、2和3组分别获得了约20、100和500 pg/ml的ACTH水平。第2和3组在20分钟后皮质醇分泌增加（分别从0.016±0.004增加到2.25±1.36以及从0.02±0.01增加到5.32±1.23微克·分钟-1·克皮质-1），而腺苷3',5'-环磷酸（cAMP）分泌仅在第3组在20分钟后增加（从5.7±2.8增加到61.3±18.6微克·分钟-1·克皮质-1）。第3组动物在20分钟后全肾上腺氧消耗增加（从0.89±0.16增加到1.77±0.27毫升氧·分钟-1·100克组织-1），但其他两组未增加。用放射性微球测量的CBF不受ACTH注入的影响，而第3组在30分钟后氧提取率从基线的5.9±1.4%增加到13.0±2.4%。这些数据表明，在麻醉犬中，肾上腺皮质分泌活动的增加与氧消耗的增加相关，并且这种氧消耗的增加是通过增加氧提取来满足的，而不是通过增加皮质血流量。
