title: Postnatal changes in enzyme activities of rat myocardial adenine nucleotide catabolic pathway.
abstract: Three catabolic enzymes, 5'-nucleotidase (5'NT), adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and one anabolic enzyme, myokinase (MK) involved in adenine nucleotide (AN) metabolism were studied in myocardium from 4 to 105 day old rats. The specific enzyme activities (nmoles/min/mg protein) at day 4 were 35.3 for 5'NT, 28.4 for ADA, 43.3 for PNP, and 5 X 10(3) for MK. At day 7, 5'NT, activities rose to 450%; PNP and ADA 150%; and MK 120%; of the day 4 level. The activities of the three catabolic enzymes were elevated for one or two weeks then declined rapidly. By day 34, they were slightly above the adult values. MK activity displayed a different time course. It continued to increase slowly with age after the initial surge. Compared to the adult heart, the total activities of these catabolic enzymes in the one- to three-week-old heart were 30% to 220% higher. This transient elevation in AN catabolic enzyme activities may be related to active DNA synthesis and cell proliferation occurred in the rat myocardium during the same period.
mesh_terms: D015720:5'-Nucleotidase; D000227:Adenine Nucleotides / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000378:metabolism; D000263:Adenylate Kinase / Q000378:metabolism; D000375:Aging; D000818:Animals; D001835:Body Weight; D006321:Heart / Q000254:growth & development; D009206:Myocardium / Q000201:enzymology* / Q000378:metabolism; D009708:Nucleotidases / Q000378:metabolism; D009929:Organ Size; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000227:Adenine Nucleotides; D011683:Purine-Nucleoside Phosphorylase; D000263:Adenylate Kinase; D009708:Nucleotidases; D015720:5'-Nucleotidase; D000243:Adenosine Deaminase