Abstract |
We studied effects of enalaprilat and L-158,809, an angiotensin II type-1 receptor antagonist, on left ventricular (LV) diastolic relaxation in 11 normal control dogs and 16 LV hypertrophied (LVH) dogs with perinephritic hypertension. At baseline, LV systolic and end-diastolic pressures and end-systolic elastance were increased in the LVH group (all P < 0.01 vs. the control group). LV relaxation time constant was also prolonged (P < 0.01), suggesting impaired LV diastolic relaxation in this model of LVH. Before and after the administration of enalaprilat (0.25 mg/kg) and L-158,809 (0.30 mg/kg), LV relaxation was assessed over a wide range of LV loading conditions during vena caval occlusion. LV relaxation time constant was insensitive to load reduction in the control group, which was not affected by enalaprilat or L-158,809. In contrast, LV unloading caused a significant prolongation of the relaxation time constant in the LVH group. This load-sensitive LV relaxation abnormality was significantly improved by enalaprilat or L-158,809. These results support the concept that angiotensin II is involved in the pathogenesis of diastolic dysfunction in pressure-overloaded LVH and also suggest that angiotensin-converting enzyme inhibitors and angiotensin II type-1 receptor antagonists are potentially beneficial in the treatment of the hypertrophied heart.
|
Authors | W Hayashida, J Donckier, H Van Mechelen, A A Charlier, H Pouleur |
Journal | The American journal of physiology
(Am J Physiol)
Vol. 274
Issue 2
Pg. H609-15
(02 1998)
ISSN: 0002-9513 [Print] United States |
PMID | 9486265
(Publication Type: Journal Article)
|
Chemical References |
- Angiotensin-Converting Enzyme Inhibitors
- Antihypertensive Agents
- Imidazoles
- Tetrazoles
- Angiotensin II
- L 158809
- Enalaprilat
|
Topics |
- Angiotensin II
(physiology)
- Angiotensin-Converting Enzyme Inhibitors
(pharmacology)
- Animals
- Antihypertensive Agents
(pharmacology)
- Blood Pressure
- Diastole
(physiology)
- Dogs
- Enalaprilat
(pharmacology)
- Hemodynamics
- Hypertension, Renal
(complications, physiopathology)
- Hypertrophy, Left Ventricular
(etiology, physiopathology)
- Imidazoles
(pharmacology)
- Tetrazoles
(pharmacology)
|