Implications of changes in plasma asymmetric dimethylarginine during treatment of hypertension.

摘要

Nitric oxide (NO), an important vasoactivesubstance that exerts its effect through stimulation of cyclicguanosine monophosphate (cGMP), is produced in vascularendothelium by the action of endothelial NO synthase(eNOS). Inhibition of eNOS affects vascular tone, leadingto endothelial dysfunction. Several studies have examinedthe effect of asymmetric dimethylarginine (ADMA) on NOsynthesis. ADMA, an endogenous analogue of L-argininethat is normally degraded by dimethylarginine dimethylaminohydrolase1,2 (DDAH1,2), inhibits the action ofeNOS. Nebivolol, like other beta-adrenergic receptor (AR)blockers, has an antagonist effect at the β1-AR, but inaddition it has an agonist effect at the β3-AR subtype.Stimulation of β3-AR has been shown to result in anincrease in circulating NO.