Elinor M. Zorn

Serum gonadotropin and testosterone levels in uremic males undergoing intermittent dialysis

Abstract Twenty-six adult males with uremia due to chronic renal disease were studied to determine the circulating levels of gonadotropins. In some of these patients serum testosterone levels were also measured. Patients receiving intermittent hemodialysis had higher levels of luteinizing hormone (LH) than normals, uremic patients not receiving dialysis and patients on peritoneal dialysis. Serum testosterone levels tended to be low in uremic patients. No significant alterations in follicle-stimulating hormone (FSH) were observed in the groups studied. Uremia seems to effect Leydig cell function without producing an associated rise in gonadotropins with the exception of an increase in LH in patients on intermittent hemodialysis.

A sensitive testosterone assay by protein-binding

Abstract A sensitive assay utilizing protein-binding has been developed for the measurement of testosterone in biological fluids. The assay utilizes pregnancy serum diluted to 0.25% to which testosterone-3H has been added. Only 2 ml of peripheral serum are required to satisfactorily measure normal female levels.

Pituitary-gonadal rhythms in the eugonadal adult male.

The regulation of the pituitary-testicular axis was studied in 4 healthy male volunteers (mean age 33 married 2-4 children) at Saint Lukes Hospital in Cleveland. During a 4-hour period commencing between 8-10 AM peripheral samples were obtained every 15 minutes for the determination of follicle-stimulating hormone lutenizing hormone and testosterone. The secretions of the gonadotropins and testosterone were episodic and unrelated within each individual. The number of peaks varied interindividually and the various hormones had different numbers of peaks intraindividually. No support was gained for the concept that fluctuations of basal secretion in normal males are caused by negative feedback control.

Impaired Leydig Cell Reserve and Altered Serum Androgen Binding in the Aging Male**Supported in part by a General Research Support grant from the National Institutes of Health.

The hormonal profile of the aging male reveals an associated decrease in free testosterone and 5 alpha-dihydrotestosterone (DHT) levels and increased luteinizing hormone levels. Later events consist of a decrease in total testosterone, stable DHT, and increased follicle-stimulating hormone and estradiol levels. Although most available information supports the concept of impaired Leydig cell reserve, our study suggests some degree of hypothalamic-pituitary dysfunction. The signal for increased androgen binding with age is not clear. There is a great deal of individual variation in the time of onset of these events.