title: A combined oral contraceptive affects mucosal SHIV susceptibility factors in a pigtail macaque (Macaca nemestrina) model.
abstract: BACKGROUND
  Injectable hormonal contraception may increase women's risk of HIV acquisition and can affect biological risk factors in animal models of HIV. We established, for the first time, a model to investigate whether combined oral contraceptives (COC) alter SHIV susceptibility in macaques.
  
  
  METHODS
  Seven pigtail macaques were administered a monophasic levonorgestrel (LNG)/ethinyl estradiol (EE) COC at 33% or 66% of the human dose for 60 days. Menstrual cycling, vaginal epithelial thickness, and other SHIV susceptibility factors were monitored for a mean of 18 weeks.
  
  
  RESULTS
  Mean vaginal epithelial thicknesses were 290.8 μm at baseline and 186.2 μm during COC (P = 0.0141, Mann-Whitney U-test). Vaginal pH decreased from 8.5 during treatment to 6.5 post-treatment (0.0176 two-tailed t-test). Measured microflora was unchanged.
  
  
  CONCLUSIONS
  COC caused thinning of the vaginal epithelium and vaginal pH changes, which may increase SHIV susceptibility. 0.033 mg LNG + .0066 mg EE appeared effective in suppressing ovulation.
authors.affiliation: Animal Resources Branch, Division of Scientific Resources, National Center for Emerging Zoonotic and Infectious Diseases, CDC, Atlanta, GA, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Dietz Ostergaard
authors.forename: Katherine
authors.initials: K
authors.lastname: Butler
authors.forename: Jana M
authors.initials: JM
authors.lastname: Ritter
authors.forename: Ryan
authors.initials: R
authors.lastname: Johnson
authors.forename: Jeanine
authors.initials: J
authors.lastname: Sanders
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Powell
authors.forename: George
authors.initials: G
authors.lastname: Lathrop
authors.forename: Sherif R
authors.initials: SR
authors.lastname: Zaki
authors.forename: Janet M
authors.initials: JM
authors.lastname: McNicholl
authors.forename: Ellen N
authors.initials: EN
authors.lastname: Kersh
mesh_terms: D000818:Animals; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects / Q000494:pharmacology*; D004195:Disease Models, Animal; D004198:Disease Susceptibility / Q000139:chemically induced* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004997:Ethinyl Estradiol / Q000009:adverse effects / Q000494:pharmacology*; D005260:Female; D015658:HIV Infections / Q000503:physiopathology*; D016912:Levonorgestrel / Q000009:adverse effects / Q000494:pharmacology*; D008254:Macaca nemestrina; D008597:Menstrual Cycle / Q000187:drug effects; D009092:Mucous Membrane / Q000187:drug effects*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000503:physiopathology*; D015302:Simian Immunodeficiency Virus / Q000187:drug effects; D014621:Vagina / Q000187:drug effects
chemical_list: D003277:Contraceptives, Oral, Combined; D004338:Drug Combinations; C072593:ethinyl estradiol, levonorgestrel drug combination; D004997:Ethinyl Estradiol; D016912:Levonorgestrel
keywords: SHIV; contraception; non-human primate (NHP); susceptibility; transmission risk