Taylor P M
Department of Clinical Veterinary Medicine, University of Cambridge.
Br J Anaesth. 1998 Feb;80(2):208-12. doi: 10.1093/bja/80.2.208.
We have studied the mechanism whereby halothane induces adrenocortical activity in eight sheep anaesthetized twice for 2 h with pentobarbital. During the second hour they received infusion of nitroprusside to lower mean arterial pressure by 40 mm Hg (group NP) or on another occasion they inhaled 0.5% halothane (group HAL). Plasma concentrations of cortisol, adrenocorticotrophic hormone (ACTH), arginine vasopressin (AVP), glucose and lactate were measured. Infusion of nitroprusside increased cortisol concentrations from mean 44 (SD 33) to 256 (131) nmol litre-1 (P < 0.05), AVP from 19 (14) to 174 (102) pmol litre-1 (P < 0.05) and ACTH from 30 (17) to 54 (32) pmol litre-1. Glucose and lactate concentrations did not change significantly. After 60 min of halothane administration, there were fewer effects: plasma cortisol increased from 47 (39) to 63 (44) nmol litre-1 (P > 0.05) and AVP from 14 (11) to 32 (29) pmol litre-1 (P > 0.05) while ACTH decreased from 32 (13) to 25 (10) pmol litre-1. The AUC60-120 values for all three hormones were significantly lower in group HAL than in group NP (P < 0.01). Glucose was unchanged but lactate concentration decreased. These results support, but do not prove, the hypothesis that hypotension is the main stimulus to pituitary-adrenocortical activity during halothane anaesthesia in sheep. A direct effect of nitroprusside cannot be ruled out.
我们研究了氟烷诱导八只绵羊肾上腺皮质活动的机制，这些绵羊用戊巴比妥麻醉两次，每次2小时。在第二个小时，它们接受硝普钠输注以使平均动脉压降低40 mmHg（NP组），或者在另一次实验中吸入0.5%氟烷（HAL组）。测量了血浆皮质醇、促肾上腺皮质激素（ACTH）、精氨酸加压素（AVP）、葡萄糖和乳酸的浓度。硝普钠输注使皮质醇浓度从平均44（标准差33）nmol/L升至256（131）nmol/L（P<0.05），AVP从19（14）pmol/L升至174（102）pmol/L（P<0.05），ACTH从30（17）pmol/L升至54（32）pmol/L。葡萄糖和乳酸浓度无显著变化。给予氟烷60分钟后，影响较小：血浆皮质醇从47（39）nmol/L升至63（44）nmol/L（P>0.05），AVP从14（11）pmol/L升至32（29）pmol/L（P>0.05），而ACTH从32（13）pmol/L降至25（10）pmol/L。HAL组所有三种激素的AUC60 - 120值均显著低于NP组（P<0.01）。葡萄糖未改变，但乳酸浓度降低。这些结果支持但未证明低血压是绵羊氟烷麻醉期间垂体 - 肾上腺皮质活动的主要刺激因素这一假说。不能排除硝普钠的直接作用。
