Behavior of acid-soluble free nucleotides and nucleic acids in myocardial anoxia
Casti, A.; Medici, D.; Dall'asta, R.; Rossoni, G.; Orlandini, G.
Bollettino della Societa Italiana di Biologia Sperimentale 51(9-10): 558-564
1975
ISSN/ISBN: 0037-8771 PMID: 1203127 Document Number: 83097
Dogs weighing about 10-15 kg were treated 1 h before pentobarbital anesthesia by an injection of atropine. After intubation, the thorax was opened and an artificial infarct produced by isolating and ligating the right anterior coronary artery. After 30 min and 6 h of ischemia, the infarcted area was removed and used for the determination of nucleotides and nucleic acids. The results obtained by measuring specific radioactivity showed that, 30 min after coronary occlusion, there was a general stimulation of the synthesis of almost all nucleotides, whereas after 6 h there was a diminution in their specific radioactivity. Adenylic nucleotides increase 30 min post-infarct, while ADP and ATP were scarcely affected. Six hours post-ischemia only adenine activity was significantly diminished, while the other nucleotides were unchanged. The increment in DNA and RNA synthesis can be interpreted as an effect of hypertrophy of myocardial cells, with increased incorporation of amino acids into actomyosin. The block of RNA and DNA synthesis 6 h after infarction is correlated with diminished synthesis of nucleic acid precursors, and may also be due to inactivation of the mechanisms of protein synthesis.