THE EFFECT OF UREA ON THE BIOLOGICAL ACTIVITY OF GONADOTROPHINS OF PLACENTAL, ENDOMETRIAL AND URINARY ORIGIN

Human chorionic gonadotrophin (HCG), pregnant mare serum gonadotrophin (PMSG) and human menopausal gonadotrophin (HMG) were incubated with varying concentrations of urea at different temperatures for different times.The luteinizing hormone (LH) activity of HCG was progressively destroyed with increasing concentrations of urea. The degree of inactivation was greater at higher temperatures but the time of incubation did not affect the results.The follicle-stimulating activity of PMSG was reduced at high urea concentrations; the time of incubation was without effect.Under the experimental conditions used the LH activity of HMG was generally destroyed to a greater extent than its follicle-stimulating hormone activity.