Coronary angiogenesis during experimental hypertension: is it reversible?

BACKGROUND We investigated coronary angiogenesis and serum vascular endothelial growth factor (VEGF) and its soluble receptor-1 (sFlt-1) concentrations in two-kidney one-clip (2K1C) hypertensive rats before and after reversal of hypertension. METHODS THE ANIMAL GROUPS WERE: (i) sham-clipped for 12 weeks; (ii) 2K1C for 12 weeks; (iii) sham-clipped for 12 weeks and unclipped for 12 weeks; and (iv) 2K1C for 12 weeks and unclipped for 12 weeks. Blood samples were taken before experiments and after clipping and unclipping; capillary density was also evaluated. RESULTS Our results showed that blood pressure in hypertensive animals was higher than sham group (175 ± 10 vs. 110.3 ± 11.3 mmHg; p < 0.05). Unclipping significantly reduced blood pressure in hypertensive rats (p < 0.05). Serum VEGF and sFlt-1 levels in hypertensive group were significantly lower than sham group (VEGF: 74.36 ± 5.85 vs. 104.07 ± 7.75 pg/ml; sFlt-1: 426.67 ± 25.74 vs. 690.76 ± 41.14 pg/ml, respectively; p < 0.05). Unclipping in hypertensive animals increased serum VEGF and sFlt-1 concentrations (VEGF: 93.65 ± 8.61 vs. 74.36 ± 5.85 pg/ml; sFlt-1: 742.05 ± 79.23 vs. 426.67 ± 25.74 pg/ml, respectively; p < 0.05). In hypertensive animals, capillary density in the heart was higher than sham group, non-significantly (p > 0.05) and after unclipping, it reached to sham group level. CONCLUSIONS It seems that changes in capillary density and serum VEGF and sFlt-1 concentrations in renovascular hypertension are reversible by removing the cause of hypertension and it shows the importance of early diagnosis and treatment of hypertension in clinical condition.