[Levels of endothelins in plasma of patients with variant angina].

One of the causes of artery spasm in patients with the variant angina could be disordered interaction between the vasodilating action of endothelial derived relaxing factor and vasospastic action of endothelin. The aim of this study is to see whether endothelin participates in etiopathogenesis of the coronary artery spasms in patients with variant angina. The survey was made in 39 patients with variant angina with or without history of myocardial infarction. The control group consisted of 26 patients with chronic stable angina pectoris and 20 healthy persons of the same age and sex as patients with variant angina. One hour before examination a venous catheter had been inserted. Then Tris (pH = 10.5) was given by 5 minutes intravenous infusion followed by hyperventilation, during which the person under test was breathing for 5 minutes with a frequency of 40/min. Endothelin 1 and 2 plasma level was determined immediately before the hyperventilation test, immediately after the termination of the test and 6 minutes later. The appearing of coronary artery spasm was detected on continuous electrocardiographic monitoring. Endothelin 1 and 2 level in plasma was determined with radioimmunologic method ("Endothelin 1.2 high sensitivity (125I) assay system" manufactured in Amersham). The study showed clinical and electrocardiographic symptoms of coronary artery spasm after hyperventilation and Tris buffer infusion in all 39 patients with variant angina--but neither in those with chronic stable angina pectoris nor in healthy persons. Patients with variant angina had higher plasma endothelin 1 and 2 levels after hyperventilation and Tris infusion than those with chronic stable angina pectoris.(ABSTRACT TRUNCATED AT 250 WORDS)