title: Luteinizing hormone and gonadal steroid levels during the menstrual cycle of orangutans.
abstract: Serum luteinizing hormone (LH), progesterone, 17 beta-estradiol, and testosterone were measured during a single cycle each of five female orangutans, and urinary LH was measured in four of those cycles. Midcycle peaks in LH and luteal phase elevations in progesterone (5.7-13.8 ng/ml) suggested that the cycles were ovulatory. 17 beta-Estradiol was elevated at midcycle (163-318 pg/ml) and during the luteal phase (56-136 pg/ml) and testosterone was also elevated at midcycle (143-580 pg/ml). These hormone patterns in the orangutans closely resemble those for chimpanzees, gorillas, and human females.
mesh_terms: D000818:Animals; D004958:Estradiol / Q000097:blood*; D005260:Female; D006071:Gorilla gorilla; D015186:Hominidae / Q000502:physiology*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood* / Q000652:urine; D008597:Menstrual Cycle; D002679:Pan troglodytes; D011148:Pongo pygmaeus / Q000502:physiology*; D011374:Progesterone / Q000097:blood*; D011863:Radioimmunoassay; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone