[Protective effect of endothelin receptor subtype A antagonist BQ610 on the ultrastructure of acute ischemic myocardium in cats].
OBJECTIVE
To observe the effects of endothelin receptor subtype A antagonist BQ610 on acute ischemic myocardial injury by electronic microscopy to study whether endogenous endothelin is involved in the pathogenesis of acute myocardial ischemia.


METHODS
Acute myocardial ischemia was induced by ligation of the left anterior descending coronary artery (LAD) in 12 cats, and BQ610 was immediately injected into the occluded LAD. Controls received normal saline (NS) injection. The ultrastructure of ischemic myocardium and non-ischemic myocardium were observed 30 min after LAD ligation.


RESULTS
As compared wtih NS controls, BQ610 significantly protected the acute ischemic myocardium from ultrastructural injury, including cardiac muscle fiber swelling, myofibril disorganization and breakdown, mitochondrial swelling and endothelial swelling. In general, the non-ischemic myocardial ultrastructure was normal.


CONCLUSIONS
The results indicate that endogenous endothelin, through endothelin receptor subtype A, plays an important role in ultrastructure injury of acute ischemic myocardium in cats.
Lin
L
L
Department of Physiology, Second Military Medical University, Shanghai 200433.
Yuan
W
W
D000208:Acute Disease; D000818:Animals; D002415:Cats; D003331:Coronary Vessels / Q000601:surgery; D065128:Endothelin Receptor Antagonists; D008026:Ligation / Q000009:adverse effects; D008297:Male; D008854:Microscopy, Electron; D017202:Myocardial Ischemia / Q000209:etiology / Q000517:prevention & control*; D009206:Myocardium / Q000473:pathology / Q000648:ultrastructure; D009842:Oligopeptides / Q000494:pharmacology*; D020011:Protective Agents / Q000494:pharmacology*; D044022:Receptor, Endothelin A
D065128:Endothelin Receptor Antagonists; D009842:Oligopeptides; D020011:Protective Agents; D044022:Receptor, Endothelin A; C087220:BQ 610