Urinary estrogens, progesterone, and LH changes during normal menstrual cycles of a captive female pileated gibbon (Hylobates pileatus).

Urinary steroid hormones and luteinizing hormone (LH) were monitored in a female pileated gibbon. The LH concentration almost peaked the day after estrogens peaks. The progesterone increased sharply after the LH peaks. Our results revealed for the first time the relationship between daily changes in urinary hormones throughout normal menstrual cycles in pileated gibbon.