Cheema I R, Jones D, Sterling D, Garrett N, Martin D K
Department of Biology, Bethune-Cookman College, Daytona Beach, Florida 32114, USA.
Artery. 1994;21(5):243-55.
Protein synthesis was measured in incubated aortic smooth muscle and fast-twitch extensor digitorum longus (EDL) in both sham operated and adrenalectomized (ADX) rats. The studies were performed on four groups: a) untreated controls; b) rats treated with tumor necrosis factor (TNF) @ 50 micrograms/kg. b.w.; c) rats treated with cortisone @ 100 mg/kg/day for 5 days; or d) rats treated with cortisone plus TNF. Both TNF and cortisone suppressed protein synthesis in the aortic smooth muscle and EDL in intact animals. TNF given together with cortisone, induced a significant additional decrease in protein synthesis in both muscle types as compared to cortisone-treated rats. The rate of protein synthesis in aortic smooth muscle from sham operated rats was control > TNF > cortisone > Cortisone+TNF; in the case of EDL, rate was control > cortisone > TNF > Cortisone+TNF. In ADX animals, TNF alone did not affect protein synthesis in both aortic smooth muscle and EDL. Though cortisone alone produced a significant inhibition of protein synthesis, there was no significant further decline in protein synthesis when cortisone was given together with TNF. These findings suggest that the inhibitory effect of TNF on muscle protein synthesis is mediated through glucocorticoids.
在假手术和肾上腺切除（ADX）大鼠的孵育主动脉平滑肌和快肌趾长伸肌（EDL）中测量蛋白质合成。研究在四组中进行：a）未处理的对照组；b）用肿瘤坏死因子（TNF）以50微克/千克体重处理的大鼠；c）用可的松以100毫克/千克/天处理5天的大鼠；或d）用可的松加TNF处理的大鼠。TNF和可的松均抑制完整动物主动脉平滑肌和EDL中的蛋白质合成。与用可的松处理的大鼠相比，TNF与可的松一起给予时，两种肌肉类型的蛋白质合成均显著进一步降低。假手术大鼠主动脉平滑肌中的蛋白质合成速率为：对照组＞TNF＞可的松＞可的松 + TNF；就EDL而言，速率为：对照组＞可的松＞TNF＞可的松 + TNF。在ADX动物中，单独的TNF对主动脉平滑肌和EDL中的蛋白质合成均无影响。虽然单独的可的松对蛋白质合成有显著抑制作用，但当可的松与TNF一起给予时，蛋白质合成没有显著进一步下降。这些发现表明，TNF对肌肉蛋白质合成的抑制作用是通过糖皮质激素介导的。
