Endothelin in hypertension and proatherogenic states

The role of renal endothelin receptors in diseases associated with hypertension appears to be critical. Hirata and colleagues [184] utilized the IPRK to demonstrate that ETB receptor stimulation induced release of nitric oxide. They found that ET-1 and ET-3 released nitric oxide via ETB receptors in renal vessels. ETB receptors were downregulated in deoxycorticosterone acetate (DOCA-salt) rat kidneys explaining why ETB-mediated NO release was reduced in DOCA-salt rats, an event which may modulate renal function and blood pressure regulation in DOCA-salt hypertensive rats. They subsequently observed that expression of ETB receptors in the endothelium was decreased in IPRK from 3 disease models (rats with hypertension, diabetes mellitus, and hypercholesterolemia) compared with that in the vascular smooth muscle cell [135]. Infusion of a highly selective ETB receptor agonist, BQ-3020, reduced renal perfusion pressure in Dahl salt-resistant rats but increased renal perfusion pressure in Dahl saltsensitive rats. BQ-3020 caused a dose-dependent release of nitric oxide in both types of rats, although the level of nitric oxide release in salt-sensitive rats was lower. Similar effects of BQ-3020 were observed in Streptozotocin- induced diabetic rats and diet-induced hypercholesterolemic rats. Expression of endothelial NO synthase (eNOS) decreased in salt-sensitive rats but not in diabetic or hypercholesterolemic rats. They concluded that impaired NO release in response to stimulation of ETB receptors in these pathologic states is due, at least in part, to a decrease in endothelial ETB receptors and may play a role in vascular dysfunction usually associated with arteriosclerosis-related diseases.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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