抄録
The response of serum testosterone to human chorionic gonadotropin (HCG) was investigated in male children with normal endocrine function (control subjects) and those with hypothalamo-pituitary dysfunctions and gonadal disorders. Serum testosterone concentrations were determined by radioimmunoassay. HCG (3,000 units/m2 of body surface) was injected once a day for three days, and blood samples for testosterone assay were drawn before the first injection (basal testosterone level) and at 24 hours after the last injection (post-HCG testosterone level). The mean basal and post-HCG testosterone levels in 7 control
The mean basal and post-HCG testosterone levels in 7 control boys, aged from 7 months to 9-10/12 years, were 18.1±8.8 ng/dl and 240.0±28.9 ng/dl respectively. Serum testosterone rose from a mean basal level of 14.0±5.7 ng/dl to a mean post-HCG level of 117.8±50.4 ng/dl in 30 patients with cryptorchidism (aged from 1-4/12 yr. to 12-11/12 yr.), from 12 ng/dl to 34 ng/dl in a patient with XO/XY male (1-2/12 yr.), from 31.4±29.6 ng/dl to 200.7±127.7 ng/dl in 7 patients with pituitary dwarfism (aged from 3-9/12 yr. to 15-9/12 yr.), from 12.5±9.2 ng/dl to 30.5±26.2 ng/dl in two patients with Prader-Willi syndrome (aged 3-2/12 yr. and 5-1/12 yr.), and from 11.4±5.0 ng/dl to 33.4±16.8 ng/dl in 5 patients with small penis with small cryptoid tests (aged from 2-2/12 yr. to 15-9/12 yr.).
Mean basal testosterone levels were not significantly different in these various groups. Response of testosterone to HCG was significantly lower (p<0.005) in patients with cryptorchidism, XO/XY male, Prader-Willi syndrome, and small penis with small cryptoid testes than that in the control pre-pubertal boys. Although the mean post-HCG testosterone level in patients with pituitary dwarfism did not differ from that in the control boys, each case showed variable response. Three out of 7 patients with pituitary dwarfism showed lower responses, and one patient with secondary sexual development showed a significantly higher response than did the control pre-pubertal boys. Two patients with Prader-Willi syndrome, whose testosterone responses to HCG were minimal, exhibited normal responses of serum LH and FSH to LH-RH. This fact suggests that the genesis of hypogonadism in Prader-Willi syndrome was not only hypothalamic dysfunction but also primary dysgenetic testicular function. Serum gonadotropin response to LH-RH was low in two out of 5 patients with small penis with small cryptoid testes, and basal FSH level was significantly high in the other three. These findings in these patients suggest that secondary hypogonadism and primary hypogonadism were included in this symptomen complex.
It is concluded that a HCG test is a useful tool for the examination of testicular function and for the differential diagnosis of hypogonadism in childhood as well as a LH-RH test.
