hCG Stimulation Test Research Articles

AGE DEPENDENCE OF TESTOSTERONE PRECURSORS IN PLASMA OF NORMAL ADULT MALES

Radioimmunoassays for the measurement of pregnenolone, 17alpha-hydroxyprogesterone, androstenedione, dehydroepiandrosterone (DHEA) and androstenediol (5-androstene-3beta, 17beta-diol) have been developed. In addition the reliability criteria of these methods have been established. Age dependence of testosterone precursors in plasma was studied in 80 normal males aged 19 to 93 years. When a young to middle aged group (19-54 years) was compared with an old age group (67-93 years) a highly significant (P less than 0.001) decrease was observed for all the precursors studied: DHEA -68.1%, pregnenolone -60.3%, androstenediol -53.8%, 17alpha-hydroxyprogesterone -47.5% and androstenedione -39.2%.

Unconjugated Dehydroepiandrosterone Plasma Levels in Normal Subjects from Birth to Adolescence in Human: The Use of a Sensitive Radioimmunoassay1

A specific and sensitive radioimmunoassay for measuring unconjugated plasma dehydroepiandrosterone (DHA) has been developed and the results expressed in ng/100 ml. Mean values +/-1 SD were in mixed cord blood 593.3 +/- 186.5 in 21 females and 712.7 +/- 190.9 in 18 males. During the first day of life the peripheral plasma concentration of DHA was 917.6 +/- 317.8 in 22 female and 922.65 +/- 290 in 17 male neonates. During the first month of age, DHA levels decreased significantly and then more progressively throughout the first year of life. Mean levels observed between the first and 6th month of life were 147.1 +/- 53.6 in 15 girls and 151.6 +/- 62.7 in 28 boys. Between 6 and 12 months of age mean DHA levels were 90.9 +/- 43.3 and 68.14 +/- 30.9 in 11 girls and 24 boys, respectively. In 250 normal children, plasma DHA levels were very low between 1 to 6 years of age, but rising progressively thereafter without any sex difference long before any clinical sign of puberty. A circadian rhythm parallel to that of cortisol was observed as early as 5 years of age. Acute and chronic stimulation of ACTH confirmed the adrenal origin of DHA, while the results of hCG stimulation test and fluoxymesterone suppression test assessed the testicular participation to the DHA production.

The testis in patients with abnormalities of sex differentiation. Histology and endocrine function.

ABSTRACT Testicular function was studied in 18 patients with abnormalities of sexual differentiation. Fourteen patients were prepubertal and four postpubertal. Plasma testosterone was determined before and after 5000 IU HCG administered daily during 5' days. Of the fourteen prepubertal patients, the two true hermaphrodites and the patient with asymmetrical gonadal differentiation showed a poor response to gonadotrophin stimulation. This could be explained by the small amount of active testicular tissue or its coexistence with ovarian and rudimentary gonadal tissue which might exert some influence on the endocrine function of the testis. In the group of eight patients with male pseudo-hermaphroditism and ambiguous external genitalia, the response to HCG showed a large variation. The three patients with small testes had lowest values i. e. 210, 198 and 192 ng/100 ml. The remaining five patients showed normal values ranging between 360 and 720 ng/100 ml. The ambiguous external genitalia of these patients could be explained as being due to a diminished androgen target organ sensitivity limited to the external genitalia. The three prepubertal patients with male pseudo-hermaphroditism and female external genitalia showed a marked increase in plasma testosterone with HCG ranging between 598 and 1100 ng/100 ml. The four pubertal cases also had high values in basal conditions, between 920 and 1870, which increased even more after gonadotrophin stimulation, in one case from 1382 to 2264 ng/100 ml. This hypersensitivity to exogenous HCG, even in infancy, correlates with the elevated basal values observed in adult patients with otherwise female external genitalia and androgen insensitivity. Finally, the HCG stimulation test could be useful for the demonstration of testicular tissue in prepubertal patient with abnormalities of sexual differentiation, although it cannot be used as a prognosis of masculinization or feminization at puberty.

Hypogonadotropic eunuchoidism. II. Gonadal responsiveness to exogenous gonadotropins.

Hypogonadotropic eunuchoidism (H.E.) is a familial disorder characterized by selective gonadotropin deficiency and sexual infantilism. Cryptorchidism and olfactory dysfunction often accompany the hormonal abnormalities. An additional defect in testis, resulting in a lack of responsiveness to exogenous gonadotropin administration, has been suggested by the observations of some investigators, but not by those of others. The present study was designed to reassess whether men and women with H.E. do respond appropriately to exogenous gonadotropin stimulation. During acute studies, testosterone increments during a standard 4-day hCG stimulation test were compared in a group of 6 hypogonadotropic patients who had received exogenous gonadotropins until one month prior to study and in 5 normal men. Serum testosterone levels increased at least two-fold in each of 5 patients with scrotal testes as in normal men. However, no response was demonstrated in the sixth patient with H.E., a subject with bilateral cryptorchi...