Subcellular distribution of cardiac 5'-nucleotidase: alteration of microsomal pool in hypertrophied pig heart.
The subcellular distribution of the 5'-nucleotidase activity was investigated in normal and hypertrophied pig hearts; normal rat hearts were used for comparison. The left ventricular hypertrophy was induced in pigs by banding the supravalvular aorta for 4, 8 and 12 weeks. By employing different procedures for the isolation of cardiac membranes, a major catalytic site for 5'-nucleotidase was found to be located at sarcolemma in rat heart and microsomes (sarcoplasmic reticulum) in pig heart. A progressive decrease in the homogenate and microsomal 5'-nucleotidase activity occurred upon the development of myocardial hypertrophy in pigs. This reduction in microsomal 5'-nucleotidase activity was characterized by a depression in both apparent Vmax and Km values. These results indicate that a primary 5'-nucleotidase pool is present in the intracellular compartment of the pig heart and is altered during the development of hypertrophy.
D015720:5'-Nucleotidase; D000818:Animals; D001011:Aorta / Q000502:physiology; D006332:Cardiomegaly / Q000201:enzymology*; D002458:Cell Fractionation; D007700:Kinetics; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology*; D009708:Nucleotidases / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology; D013552:Swine; D013997:Time Factors
D009708:Nucleotidases; D015720:5'-Nucleotidase