title: Protective effect of adenosine against a calcium paradox in the isolated frog heart.
abstract: The effect of adenosine on the calcium paradox in the isolated frog heart was studied. Addition of adenosine during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein and creatine kinase release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that adenosine protected frog myocardial cells by reducing the massive calcium influx during reperfusion possibly through an action on calcium channels. Adenosine exerted its action in a dose-dependent manner; a concentration of 10 microM adenosine provided maximum protection of myocardial cells against the calcium paradox damage. Higher concentrations of adenosine produced side effects on both electrical and mechanical activity. These results are discussed in terms of the possible mechanism involved in the protective effect of adenosine.
authors.affiliation: Department of Zoology, School of Sciences, University of Thessaloniki, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Touraki
authors.forename: A
authors.initials: A
authors.lastname: Lazou
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D003402:Creatine Kinase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006329:Heart Conduction System / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D009124:Muscle Proteins / Q000378:metabolism; D009200:Myocardial Contraction / Q000187:drug effects; D010477:Perfusion; D011895:Rana ridibunda
chemical_list: D009124:Muscle Proteins; D003402:Creatine Kinase; D000241:Adenosine; D002118:Calcium