Ramipril, compared with amlodipine, retards renal disease progression in patients with hypertensive renal disease and proteinuria and may offer benefit to patients without proteinuria.

T he purpose of this consensus statement is to offer primary care providers (including physicians, nurse practitioners, and physician assistants) a practical, evidence-based clinical tool for achieving blood pressure goals in African American patients. The need for specific recommendations for African Americans is highlighted by compelling evidence of a higher prevalence of hypertension and poorer cardiovascular and renal outcomes in this group than in white Americans. African Americans have disturbingly higher rates of cardiovascular mortality, stroke, hypertension-related heart disease, congestive heart failure, type 2 diabetes mellitus, hypertensive nephropathy, and end-stage renal disease (ESRD).

We recently demonstrated that nitric oxide (NO) significantly contributes to the mitogenic effect of vascular endothelial growth factor (VEGF), suggesting a role for the NO pathway in the signaling cascade following kinase-derivative receptor activation in vascular endothelium. The aim of this study was to investigate the intracellular pathways linked to VEGF/NO-induced endothelial cell proliferation. We assessed the activity of the mitogen-activated protein kinase (MAPK) that is specifically activated by growth factors, extracellularregulated kinase (ERK1 ⁄2 ), on cultured microvascular endothelium isolated from coronary postcapillary venules. ERK1 ⁄2 was immunoprecipitated, and its activity was assessed with an immunocomplex kinase assay. In endothelial cells exposed for 5 min to the NO donor drug sodium nitroprusside at a concentration of 100 M, ERK1 ⁄2 activity significantly increased. VEGF produced a time-and concentration-dependent activation of ERK1 ⁄2 . Maximal activity was obtained after 5 min of stimulation at a concentration of 10 ng/ml. The specific MAPK kinase inhibitor PD 98059 abolished ERK1 ⁄2 activation and endothelial cell proliferation in a concentration-dependent manner in response to VEGF and sodium nitroprusside. The NO synthase inhibitor N -monomethyl-Larginine, as well as the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, blocked the activation of ERK1 ⁄2 induced by VEGF, suggesting that NO and cGMP contributed to the VEGF-dependent ERK1 ⁄2 activation. These results demonstrate for the first time that kinase-derivative receptor activation triggers the NO synthase/guanylate cyclase pathway to activate the MAPK cascade and substantiates the hypothesis that the activation of ERK1 ⁄2 is necessary for VEGF-induced endothelial cell proliferation.

Vascular endothelial growth factor (VEGF) is a secreted protein that is a specific growth factor for endothelial cells. We have recently demonstrated that nitric oxide (NO) donors and vasoactive peptides promoting NO-mediated vasorelaxation induce angiogenesis in vivo as well as endothelial cell growth and motility in vitro; in contrast, inhibitors of NO synthase suppress angiogenesis. In this study we investigated the role of NO in mediating the mitogenic effect of VEGF on cultured microvascular endothelium isolated from coronary postcapillary venules. VEGF induced a dose-dependent increase in cell proliferation and DNA synthesis. The role of NO was determined by monitoring proliferation or guanosine 3',5'-cyclic monophosphate (cGMP) levels in the presence and absence of NO synthase blockers. The proliferative effect evoked by VEGF was reduced by pretreatment of the cells with NO synthase inhibitors. Exposure of the cells to VEGF induced a significant increment in cGMP levels. This effect was potentiated by superoxide dismutase addition and was abolished by NO synthase inhibitors. VEGF stimulates proliferation of postcapillary endothelial cells through the production of NO and cGMP accumulation.

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