Capillary growth in the heart.

Experiments were performed to test the hypothesis that increased stretch and/or tension of myocytes in the absence of changes in blood flow could induce capillary growth in the heart. Chronic treatment with either dobutamine (rabbits) or alinidine (rats) which increased force of contraction and/or stroke volume respectively without increases in coronary blood flow led to enlargement of the anatomical size of the capillary bed, with no change in cardiac weight, thus supporting the role of external mechanical factors in angiogenesis.