title: The effects of hormone replacement on the biomechanical properties of the uterosacral and round ligaments in the monkey model.
abstract: OBJECTIVE
  The purpose of this study was to determine effects of ovariectomy (OVX) and conjugated equine estrogens plus medroxyprogesterone acetate (CEE/MPA), or ethinyl estradiol plus norethindrone acetate (EE/NA) on biomechanics of uterosacral (USL) and round (RL) ligaments in postmenopausal (PMP) monkeys.
  
  
  METHODS
  This was a randomized, triple blind, placebo-controlled study. OVX monkeys received 12 months no treatment (Pbo) (n = 19), CEE/MPA (n = 19), or EE/NA (n = 21). USL and RL step strains and stress-relaxation data were curve-fitted, giving strain-dependent tensile modulus (TM) from 0% to 30%.
  
  
  RESULTS
  (1) USL: TM for both treatment groups was greater than Pbo for strains from 0% to 12% (P < .04). (2) RL: TM for both treatment groups was smaller than Pbo for strains from 12% to 30% (P < .05). No differences were found between treatment regimens.
  
  
  CONCLUSIONS
  CEE/MPA and EE/NA both affect functional biomechanical properties by increasing tensile stiffness in the USL and decreasing it in the RL.
authors.affiliation: Columbia College of Physicians & Surgeons, New York, NY, USA. Michael.Vardy@ehmc.com
authors.forename: Michael D
authors.initials: MD
authors.lastname: Vardy
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Gardner
authors.forename: Felicia
authors.initials: F
authors.lastname: Cosman
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Scotti
authors.forename: Magdy S
authors.initials: MS
authors.lastname: Mikhail
authors.forename: A Orahn
authors.initials: AO
authors.lastname: Preiss-Bloom
authors.forename: J Koudy
authors.initials: JK
authors.lastname: Williams
authors.forename: J Mark
authors.initials: JM
authors.lastname: Cline
authors.forename: Robert
authors.initials: R
authors.lastname: Lindsay
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004357:Drug Synergism; D004548:Elasticity / Q000187:drug effects; D004967:Estrogens / Q000494:pharmacology; D004966:Estrogens, Conjugated (USP) / Q000494:pharmacology; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005260:Female; D006728:Hormones / Q000494:pharmacology*; D008022:Ligaments / Q000187:drug effects / Q000502:physiology*; D008252:Macaca fascicularis; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology; D009640:Norethindrone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000077563:Norethindrone Acetate; D010052:Ovariectomy; D012404:Round Ligament of Uterus / Q000187:drug effects / Q000502:physiology*; D013718:Tensile Strength / Q000187:drug effects; D014599:Uterus
chemical_list: D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D006728:Hormones; D004997:Ethinyl Estradiol; D000077563:Norethindrone Acetate; D017258:Medroxyprogesterone Acetate; D009640:Norethindrone