title: Blood pressure variability and baroreflex sensitivity are not different in spontaneously hypertensive rats and stroke-prone spontaneously hypertensive rats.
abstract: OBJECTIVE
  To demonstrate and compare hemodynamic phenotypes of blood pressure (BP), blood pressure variability (BPV) and baroreflex sensitivity (BRS) in genetic hypertensive rats.
  
  
  METHODS
  BP was recorded continuously in conscious, freely moving rats using a computerized technique. BPV was expressed as the standard deviation of beat-to-beat BP values during a 1-h period. BRS was determined by measuring the heart period prolongation in response to the elevation in BP produced by an intravenous injection of phenylephrine.
  
  
  RESULTS
  Body weight and heart period were not different between spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SHR-SP) at the age of 15 weeks. The BP level was markedly higher in SHR-SP than SHR, whereas there were no significant differences in BPV and BRS. Quantitatively, systolic, diastolic and mean BP were significantly elevated by 36.9%, 42.9% and 39.5%, respectively, in SHR-SP compared with SHR (P < 0.01). However, their variabilities were elevated only by 14.0%, 0.4% and 10.1%, respectively, without statistical significance (P > 0.05).
  
  
  CONCLUSIONS
  BPV and BRS were not changed in parallel with the BP alterations in SHR and SHR-SP.
authors.affiliation: Department of Pharmacology, Second Military Medical University, Shanghai 200433, China.
authors.forename: Lin-shu
authors.initials: LS
authors.lastname: Zhan
authors.forename: Yun-feng
authors.initials: YF
authors.lastname: Guan
authors.forename: Ding-feng
authors.initials: DF
authors.lastname: Su
authors.forename: Chao-yu
authors.initials: CY
authors.lastname: Miao
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D013045:Species Specificity