title: Adenosine metabolism in small coronary arteries of pig.
abstract: Adenosine preferentially relaxes small coronary arteries over large ones, and small bovine coronary arteries are also known to have a higher density of adenosine receptors. Here we report a possible role of adenosine metabolism in this process. Subcellular fractions, from right coronary artery (lumen diameter of 2-3 mm) of pig designated as large coronary artery and its subsequent branches (lumen diameter of 0.5-1 mm) as small coronary arteries, were prepared and characterized. In comparison to the various large artery subcellular fractions, the corresponding small artery fractions were richer in 5'-nucleotidase but poorer in adenosine deaminase. Thus a cascade of events may promote adenosine relaxation in small coronary arteries: higher activity of 5'-nucleotidase leads to production of more adenosine, larger number of receptors allows greater reactivity to adenosine, and lower adenosine deaminase level promotes prolonged action of adenosine.
authors.affiliation: Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: A K
authors.initials: AK
authors.lastname: Grover
authors.forename: S E
authors.initials: SE
authors.lastname: Samson
authors.forename: R M
authors.initials: RM
authors.lastname: Lee
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism; D000241:Adenosine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000378:metabolism; D000818:Animals; D001158:Arteries / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D003331:Coronary Vessels / Q000378:metabolism*; D013552:Swine; D014664:Vasodilation
chemical_list: D015720:5'-Nucleotidase; D000243:Adenosine Deaminase; D000241:Adenosine; D002118:Calcium