The effect of hCG-treatment on in vitro metabolism of progesterone by the human undescended pre-pubertal testis.

Testicular biopsies from 8 pre-pubertal boys aged 3 1/2-11 years, with undescended testes, were incubated in vitro with [3H]progesterone (P). All boys had been treated with human chorionic gonadotrophin (hCG) during the 5 weeks prior to surgery. Four boys were operated within 4 days of the last injection and the remaining 4 at 12 days, 14 days, 6 months and 12 months, respectively, after hormone treatment. Significant steroid metabolic activity was demonstrated in all cases. Biopsies taken a short time after hCG-treatment (1-4 days), when blood testosterone levels were high, exhibited a high capacity for metabolizing progesterone in vitro with a low ratio of formed 20 alpha-dihydro-progesterone (20 alpha-DH-P) to 17 alpha-hydroxyprogesterone (17 alpha-OH-P), when compared to biopsies removed from subjects 12-14 days after cessation of treatment. In the latter cases and in biopsies taken at longer intervals after hormone treatment, the metabolic activity and the 20 alpha-DH-P/17 alpha-OH-P ratio had returned to levels characteristic of untreated pre-pubertal cryptorchid testes. These findings indicate that the use of hCG to provoke descent of the malpositioned testes does not result in long-lasting stimulation of steroidogenic function.