The impact of vasoactive peptides on nitric oxide production in cultured sympathetic neurons

The concentration of nitric oxide was found to be decreased in a hypersympathetic condition. We carried out experiments on cultured sympathetic neurons from 12–14-days-old chick embryos to investigate the role of vasoactive peptides and amine on nitric oxide production. Stimulation of cultured neurons with endothelin-1, norepinephrine and angiotensin-II initially increases nitric oxide production and subsequently decreases it in a dose-dependent manner (P<0.05, n=7). Stimulation of Fura-2 acetoxymethyl ester-loaded neurons with endothelin-1, norepinephrine and angiotensin-II increases the calcium influx (within 30–90s) and it is then restored to the initial level (P<0.05, n=7). An additional observation was that specific stimulator l-arginine significantly increases the nitric oxide release and calcium influx into the cells, whereas Nw-nitro-l-arginine methyl ester blunts nitric oxide release dose dependently (P<0.05, n=7) and does not change the calcium concentration in the cells.