| Most studies have confirmed that hormone levels of hypothalamus-pituitary-ovarian axis (HPO/HPG axis) will change in exercise and training in women. Because many factors affect the functions of HPG axis, the study reports are quite different. In order to full understand the effects of changes of HPG axis hormones in exercise stress, it is necessary to systematically investigate the peculiarity and rule of HPG axis hormones; to investigate the influencing factors to HPG axis; and to investigate the reaction of target cells to HPG axis hormones as the same time. Main anti-reproductive hormones and reproductive hormones are the important influencing factors to HPG axis function. HPG axis hormone receptors are the deciding factors to target cells reaction. Structure changes of every segment of HPG axis are the ultimate factors to HPG axis function. AMI will take place when HPG axis hormone level is disturbed. AMI may be related to overtraining. So resolving of these problems will be help to explain the pathological mechanisms of AMI. Animal experiment was adopted in this study, as human experiment is impossible. Experiment 1, Establishment and evaluation of animal model about athletic estrous cycle dysfunction:Female SD rats were assigned randomly to training and control groups. Training groups ran on a treadmill according to the protocal by progressive increasing training load manner. Evaluation parameters included body weight, fatigue degree, serum total T and T/C, Hb, BLA, BUN and vagina shedding cells. The results found that, during 9 weeks training period, weight gradually decreased, the range was over 1/30; fatigue degree graded >3; serum total T and T/C greatly reduced with load volume increasing; Hb level undulately decreased, distinctly appeared athletic aneamic symptoms; BUN level enhanced; BLA level continually increased; ovarian function frustration and downfall phenomena appeared ( the ratio of white cells and nucleus epithelia alternately increased; white cells were over nucleus epithelia) in vagina shedding cells monitoring. The results indicated that these parameters may be used to diagnose athletic estrous cycle dysfunction. Phenomena appeared in succession in rats, including total duration of estrous cycle prolonged, each cycle was disturbed, and estrous cycle was inhibited. These phenomena were distinct signs of estrous cycle dysfunction, and there were significant individual difference in the process. The modal accord with diagnosis criterion of overtraining, and was quietly correct. Experiment 2, Changes and roles of reproductive hormone and anti-reproductive hormone levels during progressive increasing load volume training periods in rats:In order to explore characteristics, rule, and influencing effects, this study dynamically traced the changes of reproductive hormone, anti-reproductive hormone, and HPA axis hormone levels. Equation saturation RIA was used in GnRH and B-EP determining in hypothalamus and pituitary; fluid order saturation RIA was used in serum FSH, LH, PRL, plasma B-EP, and hypothalamus and pituitary CRH; fluid equation competition RIA was used in serum E2, P, and T; competition protein binding assay was used in plasma GC. The results found that GnRH of hypothalamus and pituitary, serum LH, E2> P, T, and FSH level showed significant fall/ downfall trend, and appeared relation to intensity and duration. The obvious characteristics were lower gonadotropin and female steroids levels. CRH of hypothalamus and pituitary, and plasma GC markedly increased with training load volume increasing. B -EP of hypothalamus, pituitary and plasma, greatly enhanced with the training duration, similarly to the serum PRL level. Theresults indicated that normal relations of regulation and controlling of HPG axis hormones were disturbed; the function of HPG axis was fully inhibited; the balance of reproductive hormones and anti-reproductive hormones was destroyed. Inhibition of HPG axis was related to HPA axis enhancing and anti-reproductive hormones increasing. But the true position of HPG axis...
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