Role of nitric oxide synthase types II and III in early protection against endotoxin-induced lung injury: DISCUSSION (part 3)


Kinetics of appearance of NOS-II mRNA in several rat organs (lung, liver, heart, spleen and kidney) by dot blot analysis indicated that NOS-II transcripts appear in lung and kidney as early as 30 mins after LPS infusion. Two hours after LPS infusion, NOS-II mRNA was detected in all tested organs. We looked for confirmation of the unexpected finding by dot blot technique that pulmonary NOS-II mRNA was already expressed 30 mins after LPS treatment . Indeed, Northern blot analysis performed with DIG-labelled cDNA probe detected NOS-II mRNA in LPS-treated rats but not in lungs of control rats. To identify the lung cell type expressing the NOS-II mRNA, specific 473 base pair DIG-labelled cDNA probe was hybridized in situ in sections of rat lung. Only a few positive cells were found in lung sections from rats treated for 30 mins with LPS , with apparently different localization than those reacting with NOS-III-specific probe  . Microscopic examination under the higher magnification revealed that pulmonary vessels were filled with positive-stained cells, which may suggest that the cellular source of NOS-II in early endotoxemia is the infiltrating cells rather than induction of NOS-II in the lung parenchyma. buy ampicillin

This entry was posted in Lung injury and tagged 1-Amino-2-hydroxy-guanidine, Endotoxic shock, NG-nitro-L-arginine, Nitric oxide, Nitric oxide synthase type II, Nitric oxide synthase type III, S-nitroso-N-acetyl-penicillamine.