Decreased density of mesenteric arteries but not of myocardial endothelin receptors and function in rats with chronic ischemic heart failure.

• Mesenteric artery and cardiac ventricular endothelin receptors and endothelin-1-induced pressor responses were studied in normal rats and rats with chronic congestive heart failure induced by myocardial ischemia (4 weeks after coronary artery ligation). In mesenteric arteries of rats with chronic ischemic heart failure, endothelin receptor density was significantly decreased by 59%, whereas the dissociation constant was increased 2.8-fold, as compared with controls. There were, however, no changes in endothelin-receptor density or the dissociation constant in cardiac ventricular membrane preparations from rats with congestive heart failure as compared with controls. In pithed rats with congestive heart failure there was a reduced pressor response to a bolus injection of endothelin-1 (800 pmole/kg body weight), while the vasodilatory response was unaltered as compared with sham-operated controls. These results demonstrate that there is a decreased vascular endothelin-receptor function due to a down-regulated endothelin receptor. The in vivo data indicate that this is due to impaired endothelin A but not endothelin B receptor function. Thus, there is an impaired arterial but not cardiac ventricular endothelin receptor-mediated signalling system in the rat with chronic ischemic heart failure.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Keyword

5'-Nucleotidase

metabolism

Animals

Blood Pressure

drug effects

Chronic Disease

Decerebrate State

physiopathology

Down-Regulation

drug effects

physiology

Iodine Radioisotopes

diagnostic use

Male

Mesenteric Arteries

physiology

Myocardial Ischemia

metabolism

Myocardium

metabolism

Rats

Rats

Sprague-Dawley

Receptors

Endothelin

metabolism

Vasodilator Agents

pharmacology

Publication and Content Type

ref (subject category)

art (subject category)