Glass A R, Anderson J, Herbert D, Vigersky R A
Endocrinology. 1984 Jul;115(1):19-24. doi: 10.1210/endo-115-1-19.
A direct connection has been proposed between body size and sexual maturation by the critical body weight and critical body fat hypotheses. To test these theories in male rats, we compared the degree of sexual maturation in animals with reduced growth rate due to undernutrition with that in weight-matched but normally fed rats. Underfed rats had significantly larger prostate, seminal vesicle, and testis weights than the weight-matched normally fed controls at the three time points studied: the early pubertal period (approximate time of onset of rising serum testosterone), late pubertal period (approximate time of appearance of mature spermatids), and young adult period. At the first time point, testes of underfed rats, but not those of normally fed, weight-matched controls, showed mature step 19 spermatids, and serum testosterone was significantly higher in the underfed animals. At all time points, serum LH levels were similar in both groups, while serum FSH levels were significantly lower in the underfed rats at all points. The Lee index, an index of fatness, was significantly lower in the underfed rats. The current study indicates that underfed rats are more sexually mature than normally fed controls of the same weight despite having a lower percentage of body fat. These findings do not support the critical body weight or critical body fat hypotheses of puberty in male rats.
临界体重和临界体脂假说提出了体型与性成熟之间的直接联系。为了在雄性大鼠中验证这些理论，我们将因营养不良而生长速率降低的动物的性成熟程度与体重匹配但正常喂养的大鼠进行了比较。在研究的三个时间点：青春期早期（血清睾酮开始升高的大致时间）、青春期后期（成熟精子细胞出现的大致时间）和年轻成年期，未喂食的大鼠的前列腺、精囊和睾丸重量明显大于体重匹配的正常喂养对照组。在第一个时间点，未喂食大鼠的睾丸出现了成熟的第19阶段精子细胞，而体重匹配的正常喂养对照组则没有，并且未喂食动物的血清睾酮明显更高。在所有时间点，两组的血清促黄体生成素（LH）水平相似，而未喂食大鼠的血清促卵泡生成素（FSH）水平在所有时间点均显著较低。肥胖指数Lee指数在未喂食大鼠中显著较低。当前研究表明，尽管体脂百分比较低，但未喂食的大鼠比相同体重的正常喂养对照组性成熟程度更高。这些发现不支持雄性大鼠青春期的临界体重或临界体脂假说。
