NITRIC-OXIDE MODULATES PROSTACYCLIN BIOSYNTHESIS IN THE LUNG OF ENDOTOXIN-TREATED RATS

In this study we have investigated the correlation between prostagland in generation and the L-arginine:nitric oxide (NO) pathway in the lung of rats challenged with lipopolysaccharide. We found that in rats tre ated with L-arginine, the amount of prostacyclin, measured as 6-keto-P GF(1 alpha), was significantly increased. Conversely in rats treated w ith N-G-nitro-L-arginine methyl ester the production of 6-keto-PGF(1 a lpha) by lung was significantly decreased. Chopped lungs that had been removed from rats challenged with lipopolysaccharide and were incubat ed overnight with L-arginine or nitric oxide inhibitors, N-G-nitro-L-a rginine methyl ester or N-G-monomethyl-L-arginine, released respective ly increased or decreased amount of 6-keto-PGF(1 alpha) These results suggest that, in the rat, lung endogenous nitric oxide may modulate pr ostanoid production.