THE EFFECT OF UREA ON THE BIOLOGICAL ACTIVITY OF PITUITARY GONADOTROPHINS

Abstract

SUMMARY Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) (National Institutes of Health—NIH have been incubated with varying concentrations of urea at different temperatures and for different periods of time. The luteinizing activity of NIH-LH was destroyed to a greater extent than the follicle-stimulating activity of NIH-FSH at all concentrations of urea employed. Higher temperatures tended to increase the degree of inactivation of both FSH and LH, while the time of incubation did not affect the results. It is suggested that at concentrations of urea below 6 m inactivation of gonadotrophic activity is produced by ammonium cyanate formed from urea during incubation.