Distribution of constitutive nitric oxide synthase in the jejunum of adult rat

AIM: To study the distribution of the constitutive nitric oxidesynthase (NOS) in the jejunum of adult mt.METHODS: The distribution of endothelial NOS (eNOS) wasdetected by immunohistochemistry. Immunofluorescencehistochemical dual staining technique were used forstudying the distribution of neuronal NOS (nNOS) andeNOS. The dual stained slides were observed under aconfocal laser scanning microscopeRESULTS: Positive neuronal NOS (nNOS) and endothelialNOS (eNOS) cells were found to be distributed in laminapropria of villi, and the epithelial cell was not stained. eNOSwas mainly located in subrnucosal vascular endothelia,while nNOS was mainly situated in myenteric plexus. Somecells in the villi had both nNOS and eNOS. More than 80 %of the cells were positive for both nNOS and eNOS, the restcells were positive either for nNOS or for eNOS.CONCLUSION: The two constitutive nitric oxide synthasesam distributed differently in the jejunum of rat. nNOSdistributed in myenteric plexus is a neurotransmitter in thenon-adrenergic non-cholinergic (NANC) inhibitory nerves.eNOS distributed in endothelial and smooth muscle cells ofblood vessesels plays vasodilator role. eNOS and nNOS arecoexpressed in some cells of lamina propria of villi. NOgeneratedl by those NOS is very important in thephysiological and pathological process of small intestine.