[Changes in the specific activity and content of free nucleotides and polyamines of the infarct and pre-infarct area of the revascularized dog heart].

Changes on specific radioactivity and levels of free nucleotides and polyamines in infarcted and borderline tissue of reperfused dog heart. The changes on specific radioactivity and levels of free nucleotides and polyamines, spermine and spermidine, of reperfused heart show a different behaviour of the anoxic myocardium. An increase of both specific activity and levels of free nucleotides and polyamines after 30 minutes of ischemia is observed. A longer period of anoxia (6 hours) causes a decreased synthesis and concentration of free nucleotides and polyamines. A remarkable recovery of specific activity of these compounds after reperfusion is noted. The borderline tissue shows a similar behaviour but with smaller changes. Therefore, in our experimental conditions, ischemia does not cause an irreversible alteration in protein synthesis mechanism of myocardial cells. In addition, the reperfusion may cause a recovery of biochemical mechanisms that control the functional capacity of the cell. The polyamine changes may postulate a central role of these amines in both anoxic and reperfused heart.