,Blood pressure variability and baroreflex sensitivity are not different in spontaneously hypertensi

• 作 者: Lin-shu ZHAN Yun-feng GUAN Ding-feng SU Chao-yu MIAO
• 机 构: Department of Pharmacology,Second Military Medical University,Shanghai 200433,China
• 出 处: 中国药理学报（英文版）
• 发表日期: 2005年8期
• 关键词: blood pressure variability baroreflex hypertension genetics

Aim: 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 15weeks. 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). Conclusion: BPV and BRS were not changed in parallel with the BP alterations in SHR and SHR-SP.