Nitric oxide synthase-positive cells are detectable in gastroduodenal biopsies of patients with dyspepsia: A preliminary report

We explored the possibility of detecting nitric oxide synthase (NOS) in gastroduodenal biopsies of patients with functional dyspepsia. Biopsies were obtained from 10 patients (mean age 52.3 ± 14.1 y, M: F = 1.5) during an oesophago-gastro-duodenoscopy (OGD). They were fixed in 5% formalin, embedded in paraffin and stained immunocytochemically for neural NOS (bNOS). The cells were counted independently by two observers in four high power fields (hpf) and averaged. The duodenum stained for bNOS-immunoreactivity in more patients (n = 8) than either the corpus (n = 7) or the antrum (n = 3). The mean total cell count in gastroduodenal biopsies was 11.6 ± 10 cells per HPF. In addition to this, bNOS was detected in varicose as well as non-varicose nerve fibres in the lamina propria mucosae. Parietal cells of the gastric corpus and duodenal epithelial cells also showed bNOS immunoreactivity. In conclusion, bNOS-positive cells are detectable in gastroduodenal biopsies. This will facilitate in-depth study of the role of bNOS in patients with functional dyspepsia.