Immunostaining of NO synthases in the gastric mucosa. Scale: 100 μm. (a) nNOS immunostaining. nNOS was visible along the pit region, resulting in its wider distribution along the elongated pit in the TG mucosa. (b) iNOS immunostaining. iNOS was induced in the lower glandular region after ethanol injury in the WT mucosa, whereas it was constitutively expressed in the same region of the TG mucosa irrespective of ethanol injury.