Horm Res
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The goals of this presentation are to review the essential roles of aromatase, estrogens and the estrogen receptor in pubertal growth. Estrogen deficiency due to mutations in the aromatase gene (CYP19) and estrogen resistance due to disruptive mutations in the estrogen receptor gene have no effect on normal male sexual maturation in puberty. However, they lead to absence of the pubertal growth spurt, delayed bone maturation, unfused epiphyses, continued growth into adulthood and very tall adult stature in both sexes. ⋯ In conclusion, estrogens are essential for normal female secondary sexual maturation, bone maturation, epiphyseal fusion, pubertal growth spurt and achievement of normal bone mineral mass. Estrogens also influence insulin sensitivity and lipid homeostasis. However, estrogens do not appear to be essential for fetal survival, placental growth, or female sexual differentiation.
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Clinical Trial Controlled Clinical Trial
Effects of growth hormone replacement therapy on IGF-related parameters and on the pituitary-gonadal axis in GH-deficient males. A double-blind, placebo-controlled crossover study.
It has been suggested that growth hormone (GH) may play a regulatory role in male reproductive function. To express full anabolic effect in immature boys testosterone apparently requires the presence of GH. In GH-deficient adults, GH replacement therapy exerts a variety of anabolic actions, some of which are similar to the effects of gonadal steroids. ⋯ In conclusion, GH replacement therapy in 13 GH-deficient young adult males resulted in significant increases in total and free IGF-I as well as in ALS levels in all patients, but had no significant effect on: (1) the pituitary FSH and LH response to GnRH; (2) basal and hCG-stimulated levels of androgens and SHBG; (3) basal inhibin-B levels; (4) ACTH-stimulated cortisol secretion. By contrast, GH administration had subtle anti-androgenic effects in terms of elevated elevated estradiol levels and decreased prostate-specific antigen levels, although both parameters remained within the normal range. Thus, at the level of blood chemistry the effects of GH administration do not appear to involve major alterations in the pituitary-gonadal axis.