Studies of 5'-nucleotidase in the perfused rat heart. Including measurements of the enzyme in perfused skeletal muscle and liver.

摘要: Abstract Perfused rat hearts catalyze the hydrolysis of AMP added to perfusion fluid at a rate 35 mumol/g dry weight/min. The activity is specific for 5'-nucleoside monophosphates, little being observed with 2' and 3'-AMP. enzyme exhibits Michaelis-Menten kinetics in situ inhibited competitively by adenosine-5'-alpha, beta-methylene diphosphonate (Ki = 13 muM). This, as well nucleotide specificity, confirms that catalyzed 5'-nucleotidase. maximum 5'-nucleotidase perfused equal or greater than found heart homogenates; thus, all accessible externally. Hydrolysis endogenous was studied heart. Under aerobic conditions contain very low amounts purine nucleosides, no nucleoside effluent perfusate. anaerobic accumulate adenosine, inosine, hypoxanthine release three substances into externally also skeletal muscle liver, rates 10 17 weight/min, respectively.