Levels of immunoreactive inhibin-like material in urine during the menstrual cycle

Using a specific and sensitive radioimmunoassay, the authors determined levels of inhibin-like material in the urine of eight healthy women with normal menstrual cycle length of 28 +/- 4 days. The results revealed a cyclic variation in urinary immunoreactive inhibin levels during the menstrual cycles, with a sharp rise in levels three to four days prior to luteinizing hormone (LH) and follicle-stimulating hormone (FSH) peaks. These levels of immunoreactive inhibin may thus serve as a parameter to detect impending LH surge.