Plasma and platelet-derived vascular endothelial growth factor and angiopoietin-1 in hypertension: effects of antihypertensive therapy.
BACKGROUND
Platelets carry angiogenic growth factors vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1). Although platelet-derived growth factors are important in the pathogenesis and metastasis of malignancy, their role in the pathogenesis of complications and the response to treatment in hypertension is less known.


OBJECTIVE
To test the hypotheses that there are differences in VEGF and Ang-1 in the plasma and within platelets from patients with hypertension, and that levels change with successful treatment.


METHODS
We recruited 42 previously untreated patients with hypertension (25 male; mean age 53 years) and 30 age- and sex-matched controls. Plasma VEGF, Ang-1 and soluble P-selectin (sPsel, an index of platelet activation), and total platelet [platelet VEGF (pVEGF) and platelet Ang-1 (pAng-1)] were measured by ELISA. The patients were then treated for 6 months with amlodipine-based antihypertensive therapy, achieving a mean blood pressure below 140/80 mmHg.


RESULTS
Patients with hypertension had significantly higher levels of plasma sPsel (P =0.01), VEGF (P < 0.001) and Ang-1 (P = 0.01), as well as pVEGF (P < 0.001) and pAng-1 (P =0.02). The levels of plasma and platelet angiogenic growth factors were significantly reduced after antihypertensive treatment (VEGF, P = 0.01; pVEGF, P < 0.001; Ang-1, P < 0.001; pAng-1, P = 0.04). There were no correlations with blood pressure or the levels of sPsel.


CONCLUSIONS
Levels of plasma and intra-platelet VEGF and Ang-1 are increased in hypertension and are decreased with treatment. Platelet levels of VEGF and Ang-1 may be related to platelet activation but may also involve other mechanisms (for example, the general vascular and haemodynamic changes) that are seen in hypertension.
Nadar
S K
SK
Haemostasis, Thrombosis, and Vascular Biology Unit, University Department of Medicine, City Hospital, Birmingham B18 7QH, UK.
Blann
A D
AD
Lip
G Y H
GY
D017311:Amlodipine / Q000627:therapeutic use; D042683:Angiopoietin-1 / Q000097:blood*; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001792:Blood Platelets / Q000378:metabolism*; D001794:Blood Pressure / Q000502:physiology; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
C467630:ANGPT1 protein, human; D042683:Angiopoietin-1; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D019007:P-Selectin; D042461:Vascular Endothelial Growth Factor A; D017311:Amlodipine