[Effects of castration on the gonadotropin level in prepubertal males--a study on pubertal development]

The effects of prepubertal castration on circulating levels of LH and FSH were examined longitudinally in 3 male pseudohermaphrodites (1 yr., 6 yrs., 9 yrs.) and one Lt. monorchid (7 yrs.), and gonadotropin levels of prepubertal anorchism (9 yrs.) were also studied longitudinally. After castration, plasma LH and FSH concentration in the patient 1 yr. of age elevated significantly and progressively, but in two other patients 6 and 7 yrs. of age, a significant elevation of plasma LH and FSH was not observed from 90 to 450 days after the castration. Plasma LH and FSH concentration of one patient 9 yrs. of age, castrated at 1 yr., showed prepubertal values from 9 to 11 yrs. of age, and the abrupt elevation of LH and FSH occurred at 11-2/12 yrs. of age. From these observations we concluded that although castration in early childhood resulted in an immediate elevation of gonadotropin levels, a significant elevation of gonadotropin did not occur in midchildhood castration. These findings have also confirmed the evidence that the hypothalamic-pituitary-gonadal negative feedback mechanism is operative in early childhood, and supported the action of a CNS inhibitory mechanism which restrains the gonadotropin synthesis and secretion and inhibits puberty during the interval of mid-childhood.