Local anesthetics inhibit nitric oxide production and l-arginine uptake in cultured bovine aortic endothelial cells

Abstract

Previous studies have shown that local anesthetics have various effects on nitric oxide (NO) production, but the mechanisms remain unclear. The purpose of this study was to evaluate the effects of local anesthetics on NO production and 2-amino-5-guanidinopentanoic acid (l-arginine) uptake in one cell line. Cultured bovine aortic endothelial cells (BAEC) were stimulated with bradykinin and/or acetylcholine to activate endothelial NO synthase (NOS). BAEC were also incubated with interleukin-1β and lipopolysaccharide to stimulate inducible NOS. NO production was measured with the rapid spectrophotometric method, and l-arginine uptake was measured with high performance liquid chromatography. To assess the effects of local anesthetics, NO production and l-arginine uptake were measured in the presence or absence of procaine or lidocaine. NO was produced in BAEC stimulated with bradykinin and acetylcholine or interleukin-1β and lipopolysaccharide, but NO production was not affected by the addition of superoxide dismutase. In the cells stimulated with bradykinin and acetylcholine, 10μM each of procaine and lidocaine significantly inhibited NO production by 35% and 20%, respectively. In the cells incubated with interleukin-1ß and lipopolysaccharide, the same quantities of procaine and lidocaine significantly inhibited NO production by 15% and 10%, respectively. Both procaine and lidocaine significantly suppressed l-arginine uptake in BAEC stimulated with either bradykinin/acetylcholine or interleukin-1β/lipopolysaccharide. It is suggested that inhibitory effects of procaine and lidocaine on NO production are partially due to suppression of l-arginine uptake.