title: High tail-cuff blood pressure in mice 1 week after shipping: the need for longer acclimation.
abstract: BACKGROUND
  For vendor-derived mice, an acclimation period of 1 week is usually recommended before blood pressure measurements are started. However, we observed hypertension in wild-type vendor-derived mice 1 week after shipping.
  
  
  METHODS
  The index group (n = 12, BALB/c, age 3 months, weight 26-28 g) was shipped overnight (by truck, duration 13 h). Tail-cuff systolic blood pressures (SBPs) of the index group were compared to two control groups (n = 6/group), one acclimated for 3 weeks after shipping, and one derived from an in-house colony.
  
  
  RESULTS
  One week after shipping, SBP in the index group was 141 ± 3 mm Hg. Because this was much higher than reported previously for this strain, acclimation was prolonged. Six weeks after shipping, SBP had fallen to 124 ± 3 mm Hg (P < 0.005). During this time, heart rate also fell from 721 ± 15 to 665 ± 13 bpm (P < 0.01). SBP in the two control groups was also lower than in the index group 1 week after shipping, including the group acclimated for 3 weeks (129 ± 3 vs. 141 ± 3 mm Hg, P < 0.05) and the in-house mice (124 ± 3 vs. 141 ± 3 mm Hg, P < 0.005).
  
  
  CONCLUSIONS
  Vendor-derived mice are hypertensive 1 week after shipping, become normotensive after 3 weeks, but do not return to levels of in-house mice until after 6 weeks. Acclimation periods of at least 3 weeks are required when measuring blood pressure in mice.
authors.affiliation: Division of Nephrology and Hypertension, Oregon Health and Science University, Portland, USA.
authors.forename: Ewout J
authors.initials: EJ
authors.lastname: Hoorn
authors.forename: James A
authors.initials: JA
authors.lastname: McCormick
authors.forename: David H
authors.initials: DH
authors.lastname: Ellison
mesh_terms: D000064:Acclimatization; D000818:Animals; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D006973:Hypertension / Q000209:etiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013315:Stress, Psychological / Q000503:physiopathology; D013623:Tail; D013997:Time Factors; D014186:Transportation