Expression of neuronal nitric oxide synthase in several cell types of the rat gastric epithelium

The aim of this study was to identify which cell types of the rat gastric e pithelium express neuronal nitric oxide synthase (nNOS) because the results of the previous studies have been very divergent regarding this point. By the combination of immunohistochemical (IHC) and in situ hybridization (ISH ) techniques, we detected expression of nNOS in chief and mucosecretory cel ls of the gastric epithelium. Moreover, some gastric endocrine cells were i mmunoreactive for nNOS, although they could not be distinguished in section s treated with ISH techniques. The strongest signal for all antibodies in I HC techniques was obtained when microwave (MW) healing was performed before the IHC procedure. Our results indicate that in the gastric epithelium a v ariety of cell types are able to produce NO. The NO produced by the differe nt cell types (chief, mucous, and endocrine) may form a complex network of paracrine communication with an important role in gastric physiology.