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Effects of sub-chronic oral cyanide on endothelial function in rabbit aortic ringsDepartment of Pharmacology and Toxicology, University of Benin, Benin City, Nigeria, ozolua{at}uniben.edu
Department of Biochemistry, University of Benin, Benin City, Nigeria
Department of Physiology, University of Benin, Benin City, Nigeria
Department of Pharmacology and Toxicology, University of Benin, Benin City, Nigeria We have investigated how the endothelium affects vascular responses following sub-chronic low dose cyanide administration. Cyanide exists in low levels in cassava foods, which are widely consumed in tropical Africa. Adult rabbits were administered 0.38 mg/kg per day KCN po for 25 days, and responses of the isolated aortic rings to noradrenaline (NA), calcium chloride (Ca2+) and acetylcholine (ACh) were measured in vitro in the presence and absence of the endothelium. In order to establish that the dose was not toxic, animal weight, some haematological indices, plasma alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured. Results show that endothelium denudation significantly (P <0.05) attenuates NA-induced contraction in rings from cyanide-treated rabbits. There was a similar reduction in response in Ca2+-depleted NA-precontracted endothelium-denuded aortic rings from cyanide-treated rabbits. Endothelium-denuded rings from cyanide-treated rabbits showed significantly (P <0.05) enhanced relaxation to ACh. In rings from control animals, the responses to NA and Ca2+ were not significantly altered, whether in the presence or absence of the endothelium. There were no significant changes in the studied toxicological indices. We conclude that endothelial compromise is necessary for low-dose sub-chronic cyanide-induced to alter vascular reactivity to NA and ACh. Human & Experimental Toxicology (2007) 26, 105-110
Key Words: cassava foods cyanide endothelium vascular reactivity
Human & Experimental Toxicology, Vol. 26, No. 2,
105-110 (2007) |
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