Related Experiment Videos
Gastroschisis increases small bowel nitric oxide synthase activity
J F Bealer1, J Graf, S W Bruch
1Fetal Treatment Center, University of California, San Francisco 94143-0570, USA.
Journal of Pediatric Surgery
|August 1, 1996
Summary
Gastroschisis increases nitric oxide (NO) synthase activity in fetal rabbit intestines, potentially causing malabsorption and hypoperistalsis. This heightened NO synthase activity is linked to accelerated enzyme kinetics, not increased enzyme quantity.
Area of Science:
- Fetal development
- Gastroenterology
- Biochemistry
Background:
- Gastroschisis often leads to fetal intestinal damage, resulting in hypoperistalsis and malabsorption.
- Nitric oxide (NO) and NO synthase are implicated as potential mediators of this gastrointestinal dysfunction.
Purpose of the Study:
- To investigate the hypothesis that abnormal small bowel NO synthase activity contributes to the hypoperistalsis and malabsorption seen in gastroschisis.
- To determine if gastroschisis alters NO synthase activity in the fetal intestine.
Main Methods:
- Utilized a fetal rabbit model of gastroschisis.
- Measured NO synthase activity in fetal small bowel using the 3H-arginine-to-3H-citrulline conversion assay.
- Localized increased NO synthase activity to the small bowel epithelium and neurons using NADPH-diaphorase staining.
Main Results:
- Fetal rabbits with gastroschisis exhibited 2.5 times greater mean total small bowel NO synthase activity compared to controls.
- Increased NO synthase activity was localized to the small bowel epithelium and neurons.
- NADPH-diaphorase staining revealed no quantitative increase in NO synthase, suggesting accelerated enzyme kinetics.
Conclusions:
- Gastroschisis is associated with significantly increased small bowel NO synthase activity in fetal rabbits.
- The elevated NO synthase activity is likely due to accelerated enzyme kinetics rather than increased enzyme expression.
- These findings suggest a mechanistic link between increased NO synthase activity and the malabsorption and intestinal dysmotility characteristic of gastroschisis.