Local dexamethasone improves the intestinal lesions of gastroschisis in chick embryos.

BACKGROUND AND AIMS: Eviscerated bowel in gastroschisis (Gx) undergoes changes that lead to dysfunctions and create management difficulties. This study tests the hypothesis that exposure of the eviscerated bowel of chick embryos with Gx to dexamethasone might have beneficial effects on the parietal lesions.

METHODS

Gx was created in chick embryos on incubation day 15 and either dexamethasone (0.047 mg in 0.24 ml) or 0.075% saline were instilled into the amnio-allantoic chamber on day 17. The chicks were recovered near hatching (day 19) and eviscerated and non-eviscerated portions of the intestines were recovered, weighed and processed for HE and synaptophysin staining or for total DNA and protein measurements. Total mural and serosal layer thickness were determined and intramural ganglia were counted. ANOVA was used for comparison among groups with significance level set at p<0.05.

RESULTS

Chicks with Gx and Gx + saline controls had reduced body weight and tibial length in comparison with controls. The eviscerated bowel was heavier with marked wall thickening at the expense of all layers but particularly of the serosa. They had decreased total intestinal DNA with normal protein and decreased intramural ganglion density. In contrast, chicks from the Gx + dexamethasone group had normal body weight and tibial length, near-normal intestinal wall thickness with slightly increased serosal width, near-normal intestinal DNA content and normal density of intramural ganglia.

CONCLUSION

Local dexamethasone had beneficial effects on the eviscerated bowel of chicks with Gx as judged by decreased wall thickening, normalization of total intestinal DNA and richer neural population. Late gestational exposure to steroids could represent another alternative for preventing intestinal lesions in Gx.