As expected, NOS-II mRNA was detected in LPS-treated rats but not in control rats (Figure 9). These data together with the results of RT-PCR and dot blot analyses suggest that NOS-II transcripts appeared in endotoxemic rat lung not earlier than 30 mins after LPS infusion. This is why the nitric oxide that is generated by LPS from NOS-III but not NOS-II is one of the crucial factors in protecting the development of the early immediate phase of endotoxemia in the LPS-treated rats.
Figure 9 Northern blot analysis of inducible nitric oxide synthase (NOS-II) mRNA in control rat lung and in rat lungs infused for 30 mins with lipopolysaccharide (LPS). Total RNA was electo-phoresed, transferred to nylon membranes, hybridized with 473 base pair digoxigenine-labelled cDNA probe for NOS-II, and colorimetrically detected as described in Animals and Methods. NOS-II mRNA was detected 30 mins after LPS infusion but not in control lung. 18S ribosomal RNA is seen on both lanes