Effects of L-Arginine and L-NAME on Duodenal Histologic Parameters in Female Wistar Rats

Introduction: Nitric oxide (NO), as a free radical, involves in several physiologic functions in GI tract such as nerve impulse transmission and vascular tonicity regulation. Nitric oxide synthase (NOS) is the enzyme for the production of NO from L-Arginine which in turn inhibits by L-NGNitroarginine Methyl Ester (L-NAME). In the current work, we aimed to evaluate morphometric analysis of duodenum under exposure of L-Arginine and L-NAME in female Wistar rats. Methods: In this study, 5 groups (N=8) of 40 female rats (200-250 g, 8 weeks age) were chosen. Normal saline (2 mL/kg), L-Arginine (200 mg/kg), L-NAME (20 mg/kg) and L-Arginine+LNAME (with the same doses) were administered intraperitoneal — for 3 days. After 2 weeks, samples were collected, stained with hematoxylin and eosin (H&E) and observed under light microscopy. Duodenal epithelial cell height and number, gland diameter, and submucosal and muscular thicknesses were measured using optical software and analyzed by one-way ANOVA followed by Tukey’s post hoc test using SPSS-16. P≤ 0.05 was considered statistically significant. Results: There were no significant changes in mean variables compared to the control group. Conclusion: The results attested no noticeable changes in regard with the effects of L-arginine and L-NAME on duodenum parameters despite the major roles of NO in GI tract.