Capillary neoformation in the heart of dipyridamole-treated rats.

Rats were given dipyridamole i.p. (3 mg/kg initial body weight) twice a day, 5 days/week for a period of 6 weeks. Morphometric analysis of the capillary network in the myocardium was performed by electron microscopy. The capillary/fibre ratio was increased by 24% when compared with sham-injected controls. The newly-formed capillaries were located in positions where they were in contact with only two muscle fibres.