Hypertension, Vol 2, 75-82, Copyright © 1980 by American Heart Association
MM Spech, CM Ferrario and RC Tarazi
Direct measurements of arterial pressure, stroke volume (SV), and cardiac
output (CO) were obtained in ether-anesthetized rats with established
spontaneous hypertension (SHR) treated with alpha- methyldopa and compared
to both untreated hypertensive and normotensive Wistar-Kyoto (WKY) rats.
Left ventricular pumping ability was determined by the maximum levels of SV
and CO reached during rapid intravenous volume loading with blood.
Treatment with methyldopa reduced the SHR arterial blood pressure (average
57 mm Hg) and reversed the cardiac hypertrophy toward normal. In comparison
to untreated SHR, therapy increased heart rate and CO and decreased
peripheral resistance. During volume-loading, the levels of SV and CO at
matched left ventricular end-diastolic pressures were significantly higher
in treated vs untreated SHR. To evaluate the role of blood pressure in the
improved peak pumping ability observed in treated rats, a phenylephrine
infusion was used to equalize pressures while repeating cardiac function
studies. In normotensive WKY and untreated SHR, left ventricular pump
function was not greatly affected. A pronounced depression in peak SV and
peak CO was observed only in treated SHR. The data indicate that treatment
with methyldopa is associated with improved ventricular function in part
related to the reduction in arterial pressure.
ARTICLES
Cardiac pumping ability following reversal of hypertrophy and hypertension in spontaneously hypertensive rats
This article has been cited by other articles:
 |
|
 |
|
  R. E. Schmieder, J. K. Rockstroh, and F. H. Messerli Antihypertensive Therapy: To Stop or Not to Stop? JAMA, March 27, 1991; 265(12): 1566 - 1571. [Abstract] [PDF]
|
|