Abstract
An intravital fluorescence videomicroscope system was used to investigate the pharmacological effects of endothelin-1 (ET-1) on the coronary microcirculation in isolated beating hearts of rats. The heart was perfused by retrograde aortic steady flow with an oxygenated Krebs-Ringer solution containing FITC-dextran. Cumulative injections of ET-1 (1-30 pmol) elicited a dose-dependent increase in perfusion pressure from 52 ± 15 mm Hg (mean ± SEM; n = 6) before the ET-1 injection to 104 ± 23 mm Hg at the ET-1 dose of 30 pmol. A dose-dependent narrowing of microvessels was also observed on a monitor screen. This diffuse vasoconstriction was especially prominent in small arterioles; the maximum vasoconstriction of the smaller arterioles was significantly higher than that of the larger arterioles. These findings suggest that ET-1 may have an important role in governing the coronary resistance and regulating the capillary flow in myocardium.
| Original language | English |
|---|---|
| Pages (from-to) | S276-S278 |
| Journal | Journal of cardiovascular pharmacology |
| Volume | 17 |
| DOIs | |
| Publication status | Published - 1991 Jan 1 |
Keywords
- Coronary microcirculation
- Endothelin-1
- Fluorescence microangiography
- Intravital microscope system
- Rat beating heart
ASJC Scopus subject areas
- Pharmacology
- Cardiology and Cardiovascular Medicine