SHORT TERM hCG STIMULATION TEST IN PATIENTS WITH VARIOUS TYPES OF TESTICULAR INSUFFICIENCY AND ABNORMAL GENITAL DEVELOPMENT

Abstract

Estimation of testicular Leydig cell reserve capacity was attempted in patients with various types of testicular insufficiency and abnormal genital development. Serial determination of serum testosterone (T) levels was made before, during and after the im stimulation with 5000 international units (IU) of human chorionic gonadotropin (hCG) for 4 successive days. In normal adult men serum T levels were increased significantly one day after the first injection of hCG (Day 1) and it was observed that the rise in serum T levels tended to continue toward the end of the study period (Day 4).
Increments of serum T levels during and after hCG stimulation in patients with Klinefelter's syndrome were small and stunted before last hCG injection, suggesting the primary nature of testicular insufficiency in this disease and the poor Leydig cell reserve capacity. In contrast, Leydig cell reserve capacity was preserved enough in patients with Sertoli cell only syndrome.
On the other hand, in patients withhypogonadotropic hypogonadism, the basal levels of serum T were as low as those in prepubertal boys, but increments of serum T levels after hCG stimulation were found to vary in individual cases. Those patients, in whom some signs of pubertal onset were recognized, e. g., slight testicular enlargement and appearance of pubic hair, showed relatively good responses of serum T levels. However, patients with hyposmia or bilateral cryptorchidism, whose pubertal stages remained at P1 according to Tanner's standard, showed almost no response of serum T levels to hCG stimulation.
Adult patients with cryptorchidism, hypospadias, or various intersexual diseases such as true hermaphroditism, gonadal dysgenesis, mixed gonadal dysgenesis, and male hermaphroditism, showed various response patterns of serum T levels to hCG stimulation, probably depending on the nature of testicular insufficiency of their diseases as well as on the degree of testicular damages.
Most of the prepubertal patients with these diseases, however, showed almost normal responses of serum T, except for a few patients, e. g., a 3-year-old patient with gonadal dysgenesis and a 5-year-old bilaterally cryptorchid boy with Prader Willi syndrome, showing no increments of serum T levels after the hCG stimulation.