Reduced L-carnitine transport in aortic endothelial cells from spontaneously hypertensive rats.

Impaired L-carnitine uptake correlates with higher blood pressure in adult men, and L-carnitine restores endothelial function in aortic rings from spontaneously hypertensive rat (SHR). Thus, endothelial dysfunction in hypertension could result from lower L-carnitine transport in this cell type. L-Carnitine transport is mainly mediated by novel organic cation transporters 1 (Octn1, Na(+)-independent) and 2 (Octn2, Na(+)-dependent); however, their kinetic properties and potential consequences in hypertension are unknown.

The renoprotective effect of L-carnitine in hypertensive rats is mediated by modulation of oxidative stress-related gene expression.

Purpose: Arterial hypertension is associated with a high production of reactive oxygen species and a decrease in the antioxidant defense systems. Based on the lack of toxicity of L-carnitine (LC) and previous studies reporting beneficial effects of this compound in experimental models of hypertension, the aim of this work was to test the hypothesis that LC might protect the kidney against hypertension-induced oxidative damage, as well as to investigate the mechanisms involved in this effect. To this end, specific activities and protein/mRNA expression of the antioxidant enzymes (glutathione peroxidase, glutathione reductase, and superoxide dismutase), and those of NADPH oxidase (the main responsible for superoxide anion production in renal tissue) have been measured in renal cortex homogenates from NG-nitro-L-arginine methyl ester (L-NAME)-treated rats and control normotensive rats.