title: Exposure of rats to low concentration of cigarette smoke increases myocardial sensitivity to ischaemia/reperfusion.
abstract: It is suggested that passive smoking or smoke-exposure increase the risk of coronary heart disease. The same mechanisms as active smoking might play a role. The aim of this study was to determine whether exposure to smoke aggravated ischaemia/reperfusion injury. As a parameter of cellular function and integrity mitochondrial oxidative function was measured. Low molecular weight iron (LMWI) and alpha-tocopherol levels were determined to assess the possibility of toxic hydroxyl radical involvement in myocardial ischaemia/reperfusion injury of smoke-exposed rats. Rats were exposed to a small concentration of cigarette smoke for 2 months (the carboxyhemoglobin concentration did not increase), whereafter hearts were isolated and subjected to ischaemia and ischaemia followed by reperfusion. Mitochondrial oxidative function, low molecular weight iron and alpha-tocopherol were determined. The impairment in mitochondrial oxidative function, LMWI content elevation and the decrease in alpha-tocopherol concentration during ischaemia/reperfusion were significantly more severe in hearts of smoke-exposed rats than non-smokers. These results suggest that exposure to smoke increased the sensitivity of hearts to ischaemia/reperfusion injury, and that a free radical mechanism might participate.
authors.affiliation: Department of Chemical Pathology, University of the Orange Free State, Bloemfontein, Republic of South Africa.
authors.forename: H
authors.initials: H
authors.lastname: van Jaarsveld
authors.forename: J M
authors.initials: JM
authors.lastname: Kuyl
authors.forename: D W
authors.initials: DW
authors.lastname: Alberts
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005609:Free Radicals; D006321:Heart / Q000187:drug effects*; D007501:Iron / Q000378:metabolism; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D017202:Myocardial Ischemia / Q000209:etiology*; D015425:Myocardial Reperfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D012907:Smoking / Q000009:adverse effects*; D014810:Vitamin E / Q000378:metabolism
chemical_list: D005609:Free Radicals; D014810:Vitamin E; D007501:Iron