Endothelium-dependent vasorelaxation induced by L-carnitine in isolated aorta from normotensive and hypertensive rats

Abstract

The aim of this work was to investigate the mechanism of the vasodilatory effect induced by Lcarnitine. Relaxation produced by L-carnitine was studied in rat aortic rings with and without functional endothelium, pre-contracted with phenylephrine by adding cumulative doses of Lcarnitine (10 7 to 10 3 M). The relaxation evoked by L-carnitine reached higher values in aortic rings from spontaneously hypertensive rats than those obtained in arteries from normotensive rats; no relaxation was produced in de-endothelialized arteries. However, in the presence of N G -nitro-Larginine (3¬ 10 5 M, a nitric oxide synthase inhibitor), Ro 68070 (10 4 M, a thromboxane synthetase inhibitor-thromboxane A 2 /prostaglandin H 2 receptor antagonist) or ICI 192605 (10 5 M, a thromboxane A 2 receptor antagonist) the relaxant response to L-carnitine was signi cantly inhibited. These results show that L-carnitine induced endothelium-dependent relaxation in the rat aorta and the mechanism of this relaxation appeared to be mostly mediated by endothelial production of nitric oxide but also could involve prevention of the action of cyclooxygenase endothelial products acting on the thromboxane A 2 /prostaglandin H 2 receptor.

L-Carnitine Protects against Carboplatin-Mediated Renal Injury: AMPK- and PPARα-Dependent Inactivation of NFAT3

“…Nitric oxide production in the aorta of hypertensive rats is enhanced by L-carnitine through PI3 and Akt kinases [35], and PLC promotes prostaglandin synthesis in subcutaneous arteries in humans [20]. We showed that the antioxidant and anti-inflammatory properties of L-carnitine protected RTCs from carboplatin-mediated injury.…”

Propionyl-L-Carnitine Improves Hemodynamics and Metabolic Markers of Cardiac Perfusion during Coronary Surgery in Diabetic Patients

“…L-carnitine and its derivatives are known to have vasodilating properties which might be related to increased prostaglandin synthesis [22]. Both L-carnitine and propionyl-L-carnitine were previously reported to restore endothelium-dependent relaxation at reperfusion in experimental setting [23], with an action on the thromboxane A 2 /prostaglandin H 2 receptor being a possible mechanism involved [24]. All these observations highlight the importance of vascular mechanisms in the effect of carnitine derivatives.…”

Effect of <i>L</i>-Carnitine and Propionyl-<i>L</i>-Carnitine on Endothelial Function of Small Mesenteric Arteries from SHR

“…Both LC and PLC are able to induce endothelium-dependent relaxation. The former enhances NO production in the aorta from hypertensive rats [1] and the latter promotes prostaglandin synthesis in subcutaneous human arteries [2]. Furthermore, we have recently reported that both compounds improved endothelial dysfunction in aortic rings from spontaneously hypertensive rats (SHR) by increasing NO participation in endothelium-dependent relaxations.…”