Cardiovascular responses to alpha adrenergic agents in chronically-exercised spontaneously hypertensive rats. Clin Exp Hypertens A 1989;11(8):1607-25
Date
01/01/1989Pubmed ID
2612024DOI
10.3109/10641968909038186Scopus ID
2-s2.0-0024801218 (requires institutional sign-in at Scopus site) 4 CitationsAbstract
The influence of treadmill exercise training on cardiovascular regulation was investigated in spontaneously hypertensive rats (SHR) of Okamoto strain during their 8th to 18th week of life. Non-exercising age-matched SHR and Wistar-Kyoto (WKY) rats served as cage controls. Resting systolic blood pressure (SBP), heart rate (HR) and weight changes were measured in the three groups during the training period. At the completion of the training period (week 18), the trained SHR had SBP values of 164 +/- 4 mm Hg and HR values of 388 +/- 8 beats per minute, which were significantly less than (P less than 0.05) those values recorded for the control SHR (SBP = 186 +/- 3 mm Hg; HR = 422 +/- 11 bpm). The influence of exercise on baroreceptor regulation of HR was evaluated in anesthetized animals from all three groups. Phenylephrine-induced increases in mean arterial blood pressure (MAP) produced significantly greater (P less than 0.05) reflex decreases in HR in the trained SHR versus the sedentary SHR. No significant difference in baroreflex sensitivity values were noted between the WKY and trained SHR. Additionally, norepinephrine infusion produced significantly smaller (P less than 0.05) pressor responses in trained versus sedentary SHR. We conclude that exercise training significantly reduces resting SBP and HR while modifying the baroreceptor regulation of HR and cardiovascular responses to adrenergic agents in the SHR.
Author List
Bennett CH, Kotchen TAMESH terms used to index this publication - Major topics in bold
AnimalsBlood Pressure
Cardiovascular System
Heart Rate
Motor Activity
Norepinephrine
Phenylephrine
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Sympathomimetics
Time Factors
