Collagen metabolism of the rat heart during experimental cardiac hypertrophy and the effect of digitoxin treatment.

In cardiac hypertrophy the total content of collagen is increased in the myocardium. The first indicator of the increased activity of connective tissue cells is an increase in the activity of prolyl hydroxylase of the myocardium. This is later followed by an increase in the rate of collagen synthesis and subsequently collagen is accumulated in the myocardium. Digitoxin treatment prevents the hypertrophy and the accumulation of proteins to the myocardium. This effect of digitoxin is, at least partly, explained by a decreased transport of amino acids into the cells, The results emphasize the importance of amino acid supply to the process of hypertrophy.