Ontogeny of gonadotropin secretion in congenital anorchism: sexual dimorphism versus syndrome of XXXX and diagnostic considerations.

@entity1 @entity251 @entity134 @entity2689 @entity444
The hormonal characteristics of anorchism are elevated basal levels of gonadotropins, especially follicle-stimulating hormone and a low concentration of plasma @entity251 that fails to increase after the administration of @entity1 chorionic gonadotropin. However, little is known about the dynamics of plasma gonadotropin secretion in @entity1 and @entity1 with anorchism. We analyzed plasma gonadotropin concentrations and their responses to luteinizing hormone releasing factor, along with plasma @entity251 responses to @entity1 chorionic gonadotropin, in 9 @entity1 with surgically proved bilateral anorchism. Basal concentrations of gonadotropins, especially plasma follicle-stimulating hormone, are elevated above normal during the first 3 to 4 years of life, decrease gradually to normal prepubertal levels and then increase again after age 9 years. This age-dependent diphasic pattern of gonadotropin secretion is comparable to that described previously in @entity1 with the syndrome of @entity444 and it is consistent with @entity134 -independent central nervous system inhibition of pulsatile luteinizing hormone releasing factor secretion during mid childhood. Moreover, a sex difference in follicle-stimulating hormone and luteinizing hormone values was observed; the mean follicle-stimulating hormone and luteinizing hormone concentrations in anorchid @entity1 less than 3 years old were lower than in @entity1 with @entity2689 . We suggest that this sex dichotomy is a consequence, at least in part, of the actions of @entity251 derived from the fetal testis on the fetal hypothalamus. Luteinizing hormone releasing factor administration to anorchid male subjects resulted in an age-dependent augmented release of gonadotropin, particularly follicle-stimulating hormone. This study emphasizes that the age of the @entity1 must be considered when interpreting basal gonadotropin levels. We also propose that in mid childhood the luteinizing hormone releasing factor test in conjunction with the @entity1 chorionic gonadotropin stimulation test is a more accurate hormonal indicator of @entity1 with congenital anorchism than either the @entity1 chorionic gonadotropin test or basal gonadotropin concentrations.
