Oral l-arginine improves endothelial dysfunction in patients with essential hypertension

Antihypertensive and cardioprotective effects of theLagenaria sicerariafruit inNG-nitro-L-arginine methyl ester (L-NAME) induced hypertensive rats

“…Cardiac muscle fibers and coronary vascular beds express the enzyme endothelial NOS (Balligand et al, 1995). Numerous studies have shown that hypertension is accompanied by reduced endothelial function, which can be rescued to varying degrees by l-arginine supplementation (Schlaich et al, 2004;Higashi et al, 1995;Quyyumi et al, 1997;Lerman et al, 1998;Lekakis et al, 2002). l-Arginine is conditionally essential amino acid in the human diet.…”

Upregulation of Vascular Arginase in Hypertension Decreases Nitric Oxide–Mediated Dilation of Coronary Arterioles

“…This observation is in accord with previous evidence in which oral administration of L-arginine improves endothelium-dependent NO-mediated flow-mediated dilation of the brachial artery in patients with essential hypertension. 5 Nevertheless, the specific cellular mechanisms contributing to the dysregulation of L-arginine remain obscure. Interestingly, besides the NOS isoforms, arginase is another major L-arginine-consuming enzyme that converts L-arginine to L-ornithine and urea.…”

“…1 Mounting evidence suggests that this vascular impairment may be related to a diminished production and bioavailability of the potent vasodilator nitric oxide (NO), which may result from an increased vascular production of superoxide anion 2 or decreased endothelial levels of tetrahydrobiopterin 3,4 or L-arginine. 5 Interestingly, administration of NO precursor L-arginine restores endothelium-mediated vasodilatory function in patients with essential hypertension, 5 improves coronary hemodynamics in spontaneously hypertensive rats, 6 and increases NO production and reduces blood pressure in hypertensive rats with 7 or without 8 renal failure. These results suggest the possible reduction of L-arginine availability for NO synthesis in hypertension.…”

Possible Role of Oxidative Stress in the Pathogenesis of Hypertension

“…Decreased antioxidant activity (superoxide dismutase and catalase) and reduced levels of reactive oxygen species (ROS) scavengers (vitamins E and C and glutathione) may also contribute to oxidative stress (16,17,19). Furthermore, L-arginine, a NO precursor that augments endothelium-dependent vasodilation, acutely improves endothelium-dependent flowmediated dilation of the brachial artery in patients with essential hypertension (20).…”