Barton R N, Passingham B J
Am J Physiol. 1982 Sep;243(3):R416-23. doi: 10.1152/ajpregu.1982.243.3.R416.
There is evidence for a physiological role of the adrenal cortex in the early responses to limb ischemia in the rat. Trilostane, which inhibits steroid production and prevents the usual rise in corticosterone concentration, impairs compensatory fluid movement during the 3 h after removal of bilateral hindlimb tourniquets and truncates the accompanying hyperglycemia. We have now studied whether altering the corticosterone concentration has similar effects over a 3-h period after a 35% hemorrhage in the conscious rat. After hemorrhage there was only a small rise in plasma glucose concentration, which was unaffected by inhibition of the adrenocortical response with trilostane or its prolongation with adrenocorticotrophic hormone. However, if hindlimb tourniquets were applied 4 h beforehand, the hyperglycemia after hemorrhage was as large as after tourniquet removal and was similarly curtailed by trilostane. Compensatory fluid movement, in contrast, was unaffected by any of the alterations in corticosterone concentration, with or without tourniquets. Thus the method of producing fluid loss is critical in determining whether glucocorticoids play a role in compensation but not in maintaining hyperglycemia after injury.
有证据表明，肾上腺皮质在大鼠肢体缺血的早期反应中具有生理作用。曲洛司坦可抑制类固醇生成并阻止皮质酮浓度的正常升高，它会损害双侧后肢止血带去除后3小时内的代偿性液体移动，并减轻随之而来的高血糖症。我们现在研究了在清醒大鼠35%失血后的3小时内，改变皮质酮浓度是否有类似的影响。失血后，血浆葡萄糖浓度仅略有升高，用曲洛司坦抑制肾上腺皮质反应或用促肾上腺皮质激素延长其反应均未对其产生影响。然而，如果事先4小时应用后肢止血带，失血后的高血糖症与止血带去除后的一样严重，并且同样会被曲洛司坦减轻。相比之下，无论有无止血带，皮质酮浓度的任何改变都不会影响代偿性液体移动。因此，产生液体流失的方法对于确定糖皮质激素在代偿中是否起作用至关重要，但对损伤后维持高血糖症并无影响。
