Wallace J D, Cuneo R C, Bidlingmaier M, Lundberg P A, Carlsson L, Boguszewski C L, Hay J, Healy M L, Napoli R, Dall R, Rosén T, Strasburger C J
Metabolic Research Unit, Department of Medicine, University of Queensland, Princess Alexandra Hospital, 4102 Brisbane, Australia.
J Clin Endocrinol Metab. 2001 Jan;86(1):200-6. doi: 10.1210/jcem.86.1.7129.
Circulating GH consists of multiple molecular isoforms, all derived from the one gene in nonpregnant humans. To assess the effect of a potent stimulus to pituitary secretion on GH isoforms, we studied 17 aerobically trained males (age, 26.9 +/- 1.5 yr) in a randomized, repeat measures study of rest vs. exercise. Exercise consisted of continuous cycle ergometry at approximately 80% of predetermined maximal oxygen uptake for 20 min. Serum was assayed for total, pituitary, 22-kDa, recombinant, non-22-kDa, 20-kDa, and immunofunctional GH. All isoforms increased during, peaked at the end, and declined after exercise. At peak exercise, 22-kDa GH was the predominant isoform. After exercise, the ratios of non-22 kDa/total GH and 20-kDa GH/total GH increased and those of recombinant/pituitary GH decreased. The disappearance half-times for pituitary GH and 20-kDa GH were significantly longer than those for all other isoforms. We conclude that 1) all molecular isoforms of GH measured increased with and peaked at the end of acute exercise, with 22-kDa GH constituting the major isoform in serum during exercise; and 2) the proportion of non-22-kDa isoforms increased after exercise due in part to slower disappearance rates of 20-kDa and perhaps other non-22-kDa GH isoforms. It remains to be determined whether the various biological actions of different GH isoforms impact on postexercise homeostasis.
循环中的生长激素（GH）由多种分子异构体组成，在未怀孕的人类中均源自同一个基因。为了评估垂体分泌的强效刺激对GH异构体的影响，我们在一项关于休息与运动的随机重复测量研究中，对17名有氧训练的男性（年龄，26.9±1.5岁）进行了研究。运动包括在约80%的预定最大摄氧量下进行20分钟的连续循环测力计运动。对血清进行了总GH、垂体GH、22 kDa GH、重组GH、非22 kDa GH、20 kDa GH和免疫功能GH的检测。所有异构体在运动期间均增加，在运动结束时达到峰值，并在运动后下降。在运动峰值时，22 kDa GH是主要的异构体。运动后，非22 kDa GH/总GH和20 kDa GH/总GH的比值增加，而重组GH/垂体GH的比值下降。垂体GH和20 kDa GH的消失半衰期明显长于所有其他异构体。我们得出结论：1）所检测的GH的所有分子异构体在急性运动期间均增加并在运动结束时达到峰值，运动期间血清中22 kDa GH是主要的异构体；2）运动后非22 kDa异构体的比例增加，部分原因是2'0 kDa以及可能其他非22 kDa GH异构体的消失速率较慢。不同GH异构体的各种生物学作用是否影响运动后的内环境稳定仍有待确定。
