Beta-adrenergic blockade alters whole-body leucine metabolism in humans.
Beta-adrenergic blockade alters whole-body leucine metabolism in humans.
复制标题
β-肾上腺素能阻断改变人体全身亮氨酸代谢。
DOI：
10.1152/jappl.1989.67.1.221
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Kalhan,SC
中科院分区：
文献类型：
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作者：
Lamont,LS;Patel,DG;Kalhan,SC
这项研究检查了非选择性β受体阻滞剂对人体全身亮氨酸代谢的影响。5名正常健康受试者（4名男性，1名女性）在每日两次口服80 mg普萘洛尔和安慰剂5天后接受6 h预充、恒速输注L-[1- 13 C]亮氨酸。亮氨酸营业额测定示踪剂稀释和亮氨酸氧化的13 C富集过期的CO2。普萘洛尔将每日总能量消耗从1，945 +/- 177.5千卡/天降低至1，619 +/- 92.5千卡/天（P <0.05）。在β-受体阻滞剂治疗期间，观察到空腹相关血糖降低以及游离脂肪酸和酮升高减弱。普萘洛尔也增加血浆亮氨酸浓度（73.1 +/- 8.7至103.4 +/- 7.3 mumol/l; P小于0.05）和亮氨酸氧化（13.2 ± 1.2 ~ 17.1 ± 1.3 μ mol·kg ~（-1）·h ~（-1）; P <0.05），但亮氨酸周转率未发生显著改变（100.5 +/- 7.3 vs. 126.0 +/- 12.3 mumol.kg-1.h-1）。此外，普萘洛尔给药期间尿尿素氮/肌酐比值更大（0.24 +/- 0.04 vs. 0.34 +/- 0.02 mol/g; P <0.05）。这些数据表明，β-肾上腺素能系统在人体全身亮氨酸代谢的调节中发挥作用。这些变化是对骨骼肌的直接影响的结果，还是通过改变骨骼肌的燃料供应介导的间接影响，目前的研究无法区分。
This study examined the effects of a nonselective beta-blocking agent on whole-body leucine metabolism in humans. Five normal, healthy subjects (4 male, 1 female) underwent a 6-h primed, constant-rate infusion of L-[1–13C]leucine after 5 days of twice daily oral use of 80 mg propranolol and a placebo. Leucine turnover was determined by tracer dilution and leucine oxidation by 13C enrichment of the expired CO2. Propranolol decreased the total daily energy expenditure from 1,945 +/- 177.5 to 1,619 +/- 92.5 kcal/day (P less than 0.05). A fasting associated decrease in blood glucose and an attenuated rise in free fatty acids and ketones were observed during beta-blockade. Propranolol also increased plasma leucine concentrations (73.1 +/- 8.7 to 103.4 +/- 7.3 mumol/l; P less than 0.05) and leucine oxidation (13.2 +/- 1.2 to 17.1 +/- 1.3 mumol.kg-1.h-1; P less than 0.05), although leucine turnover was not significantly altered (100.5 +/- 7.3 vs. 126.0 +/- 12.3 mumol.kg-1.h-1). In addition, the urinary urea nitrogen-to-creatinine ratio was greater during propranolol administration (0.24 +/- 0.04 vs. 0.34 +/- 0.02 mol/g; P less than 0.05). These data suggest that the beta-adrenergic system plays a role in the modulation of whole-body leucine metabolism in humans. Whether these changes are the result of a direct effect on skeletal muscle or an indirect effect mediated by altering the fuel supply to skeletal muscle cannot be discriminated by the present study.