Mechanisms of reduced body growth in the pubertal feminized male rat: unbalanced estrogen and androgen action on the somatotropic axis.

摘要: It is well known that the sex difference in body growth at puberty modulated by a complex interplay between steroids and somatotropic axis; however, exact role played remains matter of controversy. The aim this study was to assess mechanisms which regulate during pubertal development. Flutamide, non-steroid-blocking androgen receptor, subcutaneously administered 30-d-old male Wistar rats for 4 wk. blockade receptor led marked elevation serum testosterone an increment estradiol. Flutamide administration decreased weight gain, IGF-I levels, hepatic mRNA, GH mRNA content. There were no significant changes concentration, pituitary reserve, lowered hypothalamic somatostatin content augmented immunoreactive stores, but did not alter GH-releasing factor stores. Our findings indicate development rat, imbalance estrogen actions determines abnormal somatic growth, least partly exerted through peripheral or modification axis occurs under high exclusive action estrogens. Potential implication coincident sex-specific regulated mode pulsatile secretion cannot be excluded from random sample study.