title: Estrogen and ghrelin increase number of submucosal urethral and anal canal blood vessels in ovariectomized rats.
abstract: OBJECTIVE
  Urinary and fecal control deteriorates after menopause, but it is not clear whether this is age or hormone related. This study investigates whether administration of estrogen and/or the anti-aging growth hormone-releasing peptide, ghrelin, improves the adverse effects of menopause/aging on urethral and anal canal submucosal blood vessel counts in middle-age rats.
  
  
  METHODS
  Female Wistar rats (13 months old) underwent ovariectomy, followed 1 month later by intraperitoneal once-daily administration of 17-beta estradiol (10 microg/kg), ghrelin (2 microg/kg), both hormones, or vehicle (n = 6 in each of four groups) for 42 days. An age-matched sham group (n = 6) received no intervention. Submucosal blood vessels were counted by light microscopy in five randomly selected fields from five nonconsecutive sections (5 microm thick) per rat of formalin-fixed and paraffin-embedded tissue blocks of the urethra and anal canal stained with hematoxylin-eosin. The results are expressed as the mean vessel number per high power field (x400).
  
  
  RESULTS
  Ovariectomy significantly reduced submucosal urethral and anal vascular counts below the sham values (7.41 +/- 0.98 versus 5.46 +/- 0.82, P = 0.003 and 7.16 +/- 1.11 versus 4.92 +/- 0.65, P = 0.0009, respectively). Estrogen restored the urethral counts (7.76 +/- 0.88, P = 0.5) and ghrelin or combined estrogen and ghrelin administration significantly increased the counts to greater than the sham counts (8.68 +/- 0.99, P = 0.04 and 9.72 +/- 1.21, P = 0.004, respectively). Estrogen, ghrelin, and combined estrogen and ghrelin administration also restored the anal counts to sham levels (7.26 +/- 0.97, P = 0.8; 6.56 +/- 0.78, P = 0.3; and 7.76 +/- 0.88, P = 0.3, respectively).
  
  
  CONCLUSIONS
  Combined or individual replacement of estrogen and ghrelin produces a beneficial effect by reversing the ovariectomy-induced decrease in urethral and anal canal submucosal vessel numbers in middle-age rats.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates. rizk.diaa@uaeu.ac.ae
authors.forename: Diaa E E
authors.initials: DE
authors.lastname: Rizk
authors.forename: Hazem A
authors.initials: HA
authors.lastname: Hassan
authors.forename: Gaber A
authors.initials: GA
authors.lastname: Ramadan
authors.forename: Mohamed
authors.initials: M
authors.lastname: Shafiullah
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Fahim
mesh_terms: D001003:Anal Canal / Q000098:blood supply*; D000818:Animals; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D054439:Ghrelin; D009092:Mucous Membrane / Q000098:blood supply; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010052:Ovariectomy; D036361:Peptide Hormones / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014521:Urethra / Q000098:blood supply*
chemical_list: D004967:Estrogens; D054439:Ghrelin; D036361:Peptide Hormones