title: Urinary steroid concentrations during natural and gonadotrophin-induced oestrus and pregnancy in the giant panda (Ailuropoda melanoleuca).
abstract: Urinary concentrations of conjugated oestrone and pregnanediol-3-glucuronide were measured during and after spontaneous and induced oestrus and during pregnancy. Behavioural oestrus was preceded by a rise in oestrone values from less than 10 ng/mg creatinine (Cr) to peaks of 45 ng/mg Cr. Maximal lordotic response and mating activity coincided with the decline in oestrone levels. After presumed ovulation, urinary pregnanediol glucuronide concentrations increased from less than 5 to 15-30 ng/mg Cr. Further increases in this steroid (to 60-80 ng/mg Cr) occurred 114 days after mating, presumably coincident with implantation. These high levels of pregnanediol glucuronide were maintained for 3 weeks, began to decline 1 week before parturition and fell to a nadir (less than 5 ng/mg Cr) immediately after delivery. When FSH was administered i.m. for 5 days, urinary oestrone values rose markedly and were maximal (580 ng/mg Cr) on Day 7. Mating first occurred on Day 20 and 500 i.u. hCG were given i.m. Urinary pregnanediol glucuronide levels during the next 5 months were similar to those in the previous year during pregnancy with values rising 105-108 days after mating. However, no birth occurred. These results support the suggestion that pandas exhibit delayed implantation and demonstrate that the panda is responsive to exogenous gonadotrophins.
mesh_terms: D000818:Animals; D002335:Carnivora / Q000652:urine*; D004970:Estrone / Q000652:urine*; D004971:Estrus / Q000187:drug effects / Q000652:urine*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000652:urine*; D011276:Pregnanediol / Q000031:analogs & derivatives* / Q000652:urine
chemical_list: C022270:pregnanediol-3 alpha-glucuronide; D004970:Estrone; D005640:Follicle Stimulating Hormone; D011276:Pregnanediol