Induction of angiogenesis in NO-deficient rat heart

Angiogenesis is known to be triggered by various stimuli including hyperten sion. It was previously found that NO-deficient hypertension is accompanied by structural remodeling of the cardiac muscle and large coronary arteries . This study was aimed to examine the qualitative subcellular alterations o f capillaries in the heart of the rats treated with L-NAME (40 mg/kg/day fo r 4 weeks). The results showed that long-lasting inhibition of NO productio n induced an apparent activation of fibroblast function. This was associate d with enhancement of fibrotization as well as with the induction of angiog enesis. Accordingly, fibroblasts were frequently located in the vicinity of capillary pericytes. which was followed bi their detachment and migration. Moreover, besides inactive or, even injured capillaries. the other ones ex hibited extensive proteosynthetic activity linked to capillary growth, prol iferation and migration of endothelial cells. The results strongly indicate enhanced triggering of the angiogenesis ill L-NAME-induced NO-deficient hy per-tension.