Gender differences in the regulation of amino acid metabolism
Gender differences in the regulation of amino acid metabolism
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DOI：
10.1152/japplphysiol.01028.2002
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发表时间：
2003-09-01
影响因子：
3.3
通讯作者：
Kalhan, SC
中科院分区：
文献类型：
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作者：
Lamont, LS;McCullough, AJ;Kalhan, SC
与女性相比，经常锻炼的男性亮氨酸氧化率更高，但赖氨酸的外观率没有增加。这种两性异形的原因尚不清楚；然而，β -肾上腺素受体活性的抑制已经被证明可以调节氨基酸代谢（Lamont, m ., McCullough, J .） [J] .生理与内分泌杂志268:E910 - E916, 1995；本研究采用双盲交叉方案，对β -肾上腺素受体阻断(β （1), β(2)-阻断）和安慰剂对照期间亮氨酸和赖氨酸的性别动力学进行了比较。在饮食控制7天后，受试者以试验特定最大O-2消耗量的50%（1小时）进行锻炼。在使用β -阻断剂进行运动时，男性的非蛋白质呼吸交换比率增加（P < 0.001），而女性的游离脂肪酸循环增加（P < 0.001）。两性在运动氨基酸动力学上也表现出明显的差异。在-肾上腺素能阻断期间锻炼时，男性增加了亮氨酸氧化（P < 0.005）和赖氨酸外观率（P < 0.009），而女性没有。这项研究表明，在β -阻断期间，锻炼的男性增加了对氨基酸（和碳水化合物）的需求，以满足能量需求，而女性增加了脂肪的动员，因此需要更少的替代燃料，如碳水化合物和氨基酸。运动中不同性别的燃料偏好受-肾上腺素能受体活动的调节。运动期间的底物可用性似乎调节了性别之间氨基酸氧化的差异。
Exercising men, compared with women, have a greater increase in leucine oxidation but not lysine rate of appearance. The cause for this sexual dimorphism is unknown; however, an inhibition of beta-adrenoreceptor activity has previously been shown to mediate amino acid metabolism (Lamont LS, McCullough AJ, and Kalhan SC. Am J Physiol Endocrinol Metab 268: E910 - E916, 1995; Lamont LS, Patel DG, and Kalhan SC. J Appl Physiol 67: 221 - 225, 1989). This study was a gender comparison of leucine and lysine kinetics during a beta-adrenoreceptor blockade (beta(1),beta(2)-blockade) and a placebo control by using a double-blind crossover protocol. Subjects exercised at 50% of their trial-specific maximal O-2 consumption ( 1 h) after 7 days of dietary control. During exercise with beta-blockade, men had an increased nonprotein respiratory exchange ratio ( P < 0.001), whereas women had an increased circulation of free fatty acids ( P < 0.001). The genders also displayed distinct differences in exercise amino acid kinetics. The men, but not the women, increased leucine oxidation ( P < 0.005) and lysine rate of appearance ( P < 0.009) when exercising during beta-adrenergic blockade. This study indicates that during beta-blockade, exercising men increase their need for amino acids ( and carbohydrate) to fuel energy needs, whereas women increase their mobilization of fat, thereby requiring less alternative fuels such as carbohydrate and amino acids. Gender-specific fuel preferences during exercise are regulated by beta-adrenergic-receptor activity. Substrate availability during exercise appears to modulate the amino acid oxidation differences between genders.