title: Circumventing the natural, frequent oestrogen waves of the female cheetah (Acinonyx jubatus) using oral progestin (Altrenogest).
abstract: Cheetah are induced ovulators, experiencing short, variable oestrogen waves year-round. Exogenous gonadotrophin administration induces ovulation, but success is variable and often improves if ovaries are quiescent. After affirming the presence of short-term oestrogenic waves, we examined the effect of the timing of administration of exogenous equine and human chorionic gonadotrophins (eCG-hCG) within the oestrogen concentration pattern on subsequent follicle development and oocyte and corpus luteum quality. We also investigated ovarian suppression using an oral progestin (Altrenogest, 7 days) and assessed whether Altrenogest moderated adrenal activity by reducing glucocorticoid metabolites. All cheetahs exhibited short (every ~7-10 days), sporadic, year-round increases in faecal oestradiol punctuated by unpredictable periods (4-10 weeks) of baseline oestradiol (anoestrous). Gonadotrophin (eCG-hCG) efficacy was not affected by oestradiol 'wave' pattern if administered ≥3 days after an oestrogen peak. Such cheetahs produced normative faecal progestagen patterns and higher numbers (P<0.06) of mature oocytes than females given gonadotrophins ≤2 days after an oestradiol peak. Altrenogest supplementation expanded the interval between oestradiol peaks to 12.9 days compared with 7.3 days without progestin pretreatment. Altrenogest-fed females excreted less (P<0.05) glucocorticoid metabolites than non-supplemented counterparts. Results show that Altrenogest is effective for suppressing follicular activity, may contribute to reduced glucocorticoid production and may result in more effective ovulation induction via gonadotrophin therapy.
authors.affiliation: Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA.
authors.forename: Adrienne E
authors.initials: AE
authors.lastname: Crosier
authors.affiliation: Smithsonian Conservation Biology Institute, National Zoological Park, 3001 Connecticut Ave., NW, Washington, DC 20008, USA.
authors.forename: Pierre
authors.initials: P
authors.lastname: Comizzoli
authors.affiliation: Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA.
authors.forename: Diana C
authors.initials: DC
authors.lastname: Koester
authors.affiliation: Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Wildt
mesh_terms: D002612:Acinonyx; D000818:Animals; D004958:Estradiol / Q000097:blood*; D005260:Female; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary*; D011372:Progestins / Q000494:pharmacology*; D014204:Trenbolone Acetate / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D011372:Progestins; C023445:altrenogest; D004958:Estradiol; D014204:Trenbolone Acetate