Nitric oxide synthase inhibition prevents intestinal damage in gastroschisis: A morphological evaluation in chick embryos

Purpose: Increased small bowel nitric oxide (NO) synthase activity accused for postnatal intestinal dysmotility in gastroschisis. The purpose of this study is to evaluate the effect of prenatal NO synthase inhibition on intes tinal damage in gastroschisis. Methods: Sixteen-day-old fertilized chick eggs were divided into 4 groups. In the control group, the allantoic and amniotic membranes were opened to c reate a common cavity. In the gastroschisis group, a defect in the abdomina l wall was made, and intestinal loops were exteriorized. In the gastroschis is pretreated with L-NAME group, gastroschisis was created, and L-NAME was administered into the amnioallantoic cavity for 4 days. In the gastroschisi s sham pretreated group, after the same surgical procedure as the previous group, same amount of saline was given beside L-NAME. At the end of 20th da y of incubation, intestinal morphological changes were investigated macrosc opically and microscopically. Results:Macroscopic changes such as shortening, thickening, and fibrous adh esions were found in the exteriorized bowels of the just gastroschisis grou p and the gastroschisis pretreated saline group. However, there was only mi ld thickening in the gastroschisis pretreated with L-NAME group. Microscopi cally, compared with the gastroschisis group, serosal thickness, muscular t hickness, and bowel wall thickness were found to be significantly lower in the gastroschisis pretreated with L-NAME group (128.0 +/- 19.3 pm and 239.5 +/- 3.0 mu m V57.0 +/- 8.2 mu m and 145.0 +/- 9.7 mu m). Conclusion: It is possible to decrease intrauterine intestinal morphologica l changes in gastroschisis by inhibiting NO synthase. Copyright (C) 1999 by W.B. Saunders Company.