Protective effects of HOE642, a selective sodium-hydrogen exchange subtype 1 inhibitor, on cardiac ischaemia and reperfusion

• Published in: Cardiovascular research Vol. 29; no. 2; pp. 260 - 268
• Main Authors: SCHOLZ, W, ALBUS, U, COUNILLON, L, GÖGELEIN, H, LANG, H.-J, LINZ, W, WEICHERT, A, SCHÖLKENS, B. A
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.02.1995
• Subjects: Animals; Antianginal agents. Coronary vasodilator agents; Biological and medical sciences; Blood Platelets - drug effects; Blood Platelets - metabolism; Cardiovascular system; Cells, Cultured; Dose-Response Relationship, Drug; Erythrocytes - cytology; Erythrocytes - drug effects; Erythrocytes - metabolism; Guanidines - pharmacology; Hydrogen-Ion Concentration; Male; Medical sciences; Myocardial Ischemia - metabolism; Myocardial Reperfusion Injury - prevention & control; Myocardium - cytology; Myocardium - metabolism; Perfusion; Pharmacology. Drug treatments; Rabbits; Rats; Rats, Sprague-Dawley; Sodium-Hydrogen Exchangers - antagonists & inhibitors; Sodium-Hydrogen Exchangers - metabolism; Sulfones - pharmacology; Human; Biochemical analysis; Rat; Hydrogen; Rodentia; Red blood cell; Cardiovascular disease; Exploration; Coronary heart disease; Myocardial disease; Biological activity; Vascular disease; Vertebrata; Mammalia; Reperfusion; Ischemia; Sodium; Animal; Myocardium; pH; Intracellular; Ion exchange
• ISSN: 0008-6363; 1755-3245
• DOI: 10.1016/0008-6363(96)88579-8

The aim was to characterise the new compound HOE642 as a selective and cardioprotective Na+/H+ exchange inhibitor in various models. The effect of HOE642 was tested in the osmotically activated Na+/H+ exchange of rabbit erythrocytes and in propionate induced swelling of human thrombocytes. Recovery of pH after an NH4Cl prepulse and effects on other ion transport systems by patch clamp technique were investigated in rat cardiomyocytes. NHE subtype specifity of the compound was determined by 22Na+ uptake inhibition in a fibroblast cell line separately expressing subtype isoforms 1-3. Protective effects of HOE642 in cardiac ischaemia and reperfusion by ligation of coronary artery were investigated in isolated working rat hearts and in anaesthetised rats. HOE642 concentration dependently inhibited the amiloride sensitive sodium influx in rabbit erythrocytes, reduced the swelling of human platelets induced by intracellular acidification, and delayed pH recovery in rat cardiomyocytes. In the isolated working rat heart subjected to ischaemia and reperfusion HOE642 dose dependently reduced the incidence and the duration of reperfusion arrhythmias. It also reduced the the release of lactate dehydrogenase and creatine kinase, and preserved the tissue content of glycogen, ATP, and creatine phosphate. In anaesthetised rats undergoing coronary artery ligation intravenous and oral pretreatment with HOE642 caused a dose dependent reduction or a complete prevention of ventricular premature beats, ventricular tachycardia, and ventricular fibrillation. The compound was well tolerated and neutral to circulatory variables. Other cardiovascular agents tested in this model were not, or were only partly, effective at doses showing marked cardiodepressive effects. HOE642 is a very selective NHE subtype 1 inhibitor showing cardioprotective and antiarrhythmic effects in ischaemic and reperfused hearts. Further development of well tolerated compounds like HOE642 could lead to a new therapeutic approach in clinical indications related to cardiac ischaemia and reperfusion.