糖皮质激素治疗对心脏蛋白质合成与降解的影响。

Effects of glucocorticoid treatment on cardiac protein synthesis and degradation.

作者信息

Clark A F, DeMartino G N, Wildenthal K

出版信息

Am J Physiol. 1986 Jun;250(6 Pt 1):C821-7. doi: 10.1152/ajpcell.1986.250.6.C821.

DOI:10.1152/ajpcell.1986.250.6.C821

Abstract

We treated rats with dexamethasone (DEX, 1 mg . kg-1 . day-1) and examined the effects of this glucocorticoid on heart protein metabolism using atrial explant and Langendorff perfusion preparations. Fasted rats treated with DEX for 2 days had significantly lower body weights (92% of control, P less than 0.001) and larger hearts (106% of control, P less than 0.005) than fasted control animals. Protein and RNA concentrations remained constant. In atrial explants, DEX treatment produced a 19% increase in protein synthesis (P less than 0.001) and a 13% increase in protein degradation (P less than 0.002). In Langendorff-perfused hearts, DEX treatment caused a 36% increase in protein synthesis (P less than 0.02), while protein degradation was 8% above control (P greater than 0.05). Thus, in contrast to their catabolic effects on skeletal muscle, glucocorticoids are anabolic on the heart. The increased accumulation of total cardiac protein during early glucocorticoid administration is mediated entirely via increased rates of synthesis.

摘要

我们用 dexamethasone（DEX，1 毫克·千克⁻¹·天⁻¹）处理大鼠，并使用心房外植体和 Langendorff 灌注标本研究这种糖皮质激素对心脏蛋白质代谢的影响。与禁食的对照动物相比，用 DEX 处理 2 天的禁食大鼠体重显著降低（为对照的 92%，P＜0.001），心脏更大（为对照的 106%，P＜0.005）。蛋白质和 RNA 浓度保持恒定。在心房外植体中，DEX 处理使蛋白质合成增加 19%（P＜0.001），蛋白质降解增加 13%（P＜0.002）。在 Langendorff 灌注的心脏中，DEX 处理使蛋白质合成增加 36%（P＜0.02），而蛋白质降解比对照高 8%（P＞0.05）。因此，与它们对骨骼肌的分解代谢作用相反，糖皮质激素对心脏具有合成代谢作用。早期给予糖皮质激素期间心脏总蛋白积累的增加完全是通过合成速率的增加介导的。