title: Effect of iloprost on reperfusion-induced arrhythmias and myocardial ion shifts in isolated rat hearts.
abstract: Isolated hearts excised from normotensive (NT) and spontaneously hypertensive (SH) rats subjected to transient normothermic global ischemia were used to study the effect of chronic treatment with iloprost on reperfusion-induced arrhythmias and myocardial ion shifts. After 30 min of ischemia, iloprost given s.c. in doses of 10, 50, 100 and 200 micrograms/kg per day for 14 days reduced the incidence of reperfusion-induced ventricular fibrillation (VF) in isolated hearts from the control value of 91 to 83, 75, 50 (P less than 0.05) and 25% (P less than 0.01) respectively, in NT rats. In the SH groups, the incidence of VF was also reduced from 100 to 75, 58, 33 (P less than 0.01) and 17% (P less than 0.001), respectively, with 10, 50, 100 and 200 micrograms/kg per day of iloprost. A similar reduction was observed in the incidence of reperfusion-induced ventricular tachycardia (VT). Ischemia and reperfusion caused significant changes in myocardial ion contents, i.e. an increase in Na+ and Ca2+ and a decrease in K+ and Mg2+ concentrations. The myocardial water content was also increased in parallel to the Na+ gain. The effect of iloprost given s.c. in doses of 50 and 200 micrograms/kg per day for 14 days was also measured on myocardial ion contents after 15- or 30-min ischemia and 30-min ischemia plus 10-min reperfusion. The higher iloprost dose significantly reduced the myocardial Na+, Ca2+ and water gains and the loss of K+ induced by ischemia and reperfusion in the NT and SH groups, while the decrease in Mg2+ content was alleviated only in SH rats. The results suggest that long-term iloprost treatment reduces the incidence of reperfusion-induced VF and VT by preventing Na+, Ca2+ and water accumulation as well as K+ and Mg2+ loss from myocardial tissue.
authors.affiliation: Department of Pharmacology, Albert Szent-Györgyi University Medical School of Szeged, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Tosaki
authors.forename: M
authors.initials: M
authors.lastname: Koltai
authors.forename: M
authors.initials: M
authors.lastname: Paubert-Braquet
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000517:prevention & control*; D002412:Cations / Q000378:metabolism; D003327:Coronary Disease / Q000188:drug therapy / Q000378:metabolism; D016285:Iloprost / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013610:Tachycardia / Q000209:etiology / Q000517:prevention & control; D014693:Ventricular Fibrillation / Q000209:etiology / Q000517:prevention & control
chemical_list: D002412:Cations; D016285:Iloprost