Polyamines and noradrenaline following myocardial hypertrophy

The aliphatic amines, spermine and spermidine, and amino-oxidase activity were evaluated in hypertrophic rabbit heart obtained following aortic arch constriction. The polyamines were determined early after surgery (at 1, 2, 4, 8 h), during the first 10 days (at 1, 2, 5, 6, 10 days) and during the following 6 months (at 1, 2, 4, 6 months) after surgery. The pattern showed a rapid increase of spermine that reached a peak at 5 days after surgery (+146%). The changes of the enzymic activity are in accordance with the behaviour of polyamines. Under the same experimental conditions the myocardial concentrations of noradrenaline were evaluated. This chemical mediator rapidly increased 1 h after aortic stenosis. The results suggest that biogenic amines are related to the metabolic phenomena at the early stages of cardiac hypertrophy, and in particular to protein synthesis.