Viru A, Tendzegolskis Z
Institute of Exercise Biology, University of Tartu, Estonia.
Clin Physiol. 1995 Jan;15(1):73-9. doi: 10.1111/j.1475-097x.1995.tb00431.x.
beta-Endorphin is metabolized to gamma- and alpha-endorphin. In order to evaluate endorphin metabolism during exercise, radioimmunoassay blood levels of alpha-, beta- and gamma-endorphins were recorded during exercise for 2 h on a cycling ergometer in 12 endurance-trained and 11 untrained male subjects. In untrained subjects, mild exercise (49 +/- 4% VO2max, mean +/- SD) did not show an increase in plasma beta-endorphin, while the levels of its metabolites rose. No changes were noted in the endurance-trained subjects. More intensive exercise (66 +/- 6% VO2max in untrained and 57 +/- 7% VO2max in trained subjects) resulted in an increase in beta-endorphin concentration in association with elevation of the alpha-endorphin level. While before and during exercise the beta-endorphin levels did not differ significantly between athletes and untrained subjects, the levels of gamma- and alpha-endorphins, as well as the molar ratios alpha/beta and gamma/beta, were significantly higher in untrained subjects. In conclusion, blood levels of beta-endorphin metabolites in the resting state and during exercise are dependent on previous training. In untrained subjects, mild exercise may result in accumulation of gamma- and alpha-endorphins in blood without a concomitant change in beta-endorphin level.
β-内啡肽会代谢为γ-内啡肽和α-内啡肽。为了评估运动过程中的内啡肽代谢情况，在12名耐力训练的男性受试者和11名未经训练的男性受试者于自行车测力计上进行2小时运动期间，记录了α-、β-和γ-内啡肽的放射免疫分析血药浓度。在未经训练的受试者中，轻度运动（49±4%最大摄氧量，平均值±标准差）并未使血浆β-内啡肽增加，但其代谢产物水平升高。耐力训练的受试者未观察到变化。更剧烈的运动（未经训练的受试者为66±6%最大摄氧量，训练的受试者为57±7%最大摄氧量）导致β-内啡肽浓度增加，同时α-内啡肽水平升高。虽然在运动前和运动期间，运动员和未经训练的受试者之间的β-内啡肽水平无显著差异，但未经训练的受试者中γ-和α-内啡肽水平以及α/β和γ/β摩尔比显著更高。总之，静息状态和运动期间β-内啡肽代谢产物的血药浓度取决于先前的训练。在未经训练的受试者中，轻度运动可能导致γ-和α-内啡肽在血液中蓄积，而β-内啡肽水平无相应变化。
