title: Mouse model of posttraumatic abdominal sepsis: survival advantage of females over males does not depend on the cecum size.
abstract: BACKGROUND
  Regardless of whether alone or in combination, cecal ligation and puncture (CLP) is the most commonly used model to emulate human polymicrobial sepsis. Numerous CLP studies have shown that female mice survive better than males. In adult mice, this effect may be partly due to the unequal cecum mass (larger in males), as cecum ligation is frequently not size standardized. Comparing two ligation approaches, we investigated whether cecum size influences gender-specific outcome differences.
  
  
  METHODS
  15-month-old (middle-aged) female and male CD-1 mice underwent sublethal trauma/hemorrhage followed by CLP 48 h later. The evaluation of cecum size (in centimeters) and filling (score) was immediately followed by two ligation protocols: (1) ileocecal ligation (IC-L; n = 28/each gender) below the ileocecal valve, and (2) apex ligation (AP-L; n = 31 males, n = 24 females) 2 cm from the apex ceci - all followed by an identical double puncture and 10-day monitoring.
  
  
  RESULTS
  Cecum length (3.4 cm in males vs. 2.65 cm in females) and filling (2.5 score points in males vs. 1.7 in females; both p < 0.05) were always greater in male than female mice (27 vs. 44%, respectively). Compared to AP-L, the 10-day CLP mortality was higher with IC-L (86% in males and 61% in females), and this exacerbation was similar in both genders (by 21% in male and 23% in female mice). Finally, the intergender comparison demonstrated that female mice displayed a significant and similar survival advantage regardless of the ligation approach: the difference reached 25% with IC-L and 24% with AP-L.
  
  
  CONCLUSIONS
  Standardization by AP-L did not eliminate the gender-specific difference in mortality due to posttraumatic sepsis. The greater cecum length/filling in middle-aged male mice was not responsible for their inferior survival compared to females.
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Center, Vienna, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Wehrenpfennig
authors.forename: Susanne
authors.initials: S
authors.lastname: Drechsler
authors.forename: Katrin M
authors.initials: KM
authors.lastname: Weixelbaumer
authors.forename: Soheyl
authors.initials: S
authors.lastname: Bahrami
authors.forename: Marcin F
authors.initials: MF
authors.lastname: Osuchowski
mesh_terms: D000007:Abdominal Injuries / Q000150:complications* / Q000473:pathology; D000818:Animals; D002432:Cecum / Q000293:injuries* / Q000473:pathology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008026:Ligation; D008297:Male; D051379:Mice; D009929:Organ Size; D011677:Punctures; D018805:Sepsis / Q000209:etiology* / Q000473:pathology; D012727:Sex Characteristics