title: Use of the progestin challenge test in nonhuman primates (Macaca fascicularis).
abstract: OBJECTIVE
  To determine whether the progestin challenge test (PCT) would provide a reliable, noninvasive indicator of endometrial stimulation in nonhuman primates. DESIGN; Randomized, 2x2, crossover study. SETTING; Nonhuman primates (Macaca fascicularis) in an academic research environment.
  
  
  METHODS
  Adult, surgically postmenopausal, female cynomolgous macaques (n = 27) were studied.
  
  
  METHODS
  Females were randomly assigned to receive estradiol (n = 14; 0.028 mg/kg body weight) or vehicle (n = 13) daily. All animals were administered two PCTs in a crossover study design using two doses (0.28 mg/kg or 0.56 mg/kg body weight) of medroxyprogesterone acetate (MPA).
  
  
  METHODS
  Incidence and severity of withdrawal bleeding and serum estradiol (E(2)) and progesterone (P(4)) levels were evaluated.
  
  
  RESULTS
  Estradiol treatment resulted in endometrial "withdrawal" bleeding in all but one instance. Females receiving daily doses of E(2) exhibited a significantly greater (P<.01) incidence, severity, and duration of withdrawal bleeding compared to control animals. Of the five positive responses observed in the control females, four occurred when the higher dose of MPA was administered.
  
  
  CONCLUSIONS
  These results indicate that the PCT is a useful, noninvasive method for determining the presence of endometrial stimulation in nonhuman primates.
authors.affiliation: Wake Forest University School of Medicine, Comparative Medicine Clinical Research Center, Winston-Salem, North Carolina 27157, USA. rblair@wfubmc.edu
authors.forename: Robert M
authors.initials: RM
authors.lastname: Blair
authors.forename: J Mark
authors.initials: JM
authors.lastname: Cline
authors.forename: Mary S
authors.initials: MS
authors.lastname: Anthony
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Clarkson
mesh_terms: D000818:Animals; D018592:Cross-Over Studies; D004717:Endometrium / Q000187:drug effects / Q000502:physiology*; D004958:Estradiol / Q000008:administration & dosage / Q000097:blood; D005260:Female; D008252:Macaca fascicularis / Q000502:physiology*; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood; D045167:Progesterone Congeners / Q000494:pharmacology*; D011897:Random Allocation; D014592:Uterine Hemorrhage / Q000209:etiology
chemical_list: D045167:Progesterone Congeners; D011374:Progesterone; D004958:Estradiol; D017258:Medroxyprogesterone Acetate