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Effect of intraamniotic dexamethasone administration on intestinal absorption in a rabbit gastroschisis model
W Guo1, F Swaniker, E W Fonkalsrud
1Division of Pediatric Surgery, UCLA School of Medicine 90024, USA.
Insights
Prenatal dexamethasone treatment improved intestinal disaccharidase activity in a rabbit model of gastroschisis. This suggests potential therapeutic benefits for infants with this congenital defect.
Area of Science:
- Fetal surgery
- Neonatal development
- Gastrointestinal physiology
Background:
- Gastroschisis causes delayed intestinal motility and absorption in newborns.
- Prolonged amniotic fluid exposure is a suspected cause of intestinal dysfunction.
- Prenatal steroid administration may enhance nutrient uptake.
Purpose of the Study:
- To evaluate the effects of dexamethasone on intestinal function in a rabbit fetal gastroschisis model.
- To assess the impact of prenatal dexamethasone on disaccharidase activity.
Main Methods:
- Created gastroschisis in rabbit fetuses on gestational day 24.
- Administered dexamethasone via osmotic pump to the amniotic cavity for 7 days.
- Measured lactase and maltase enzyme activity in fetal small intestines.
Main Results:
- Lactase activity was significantly decreased in gastroschisis fetuses.
- Dexamethasone treatment increased lactase activity by 70% compared to controls.
- Maltase activity was also significantly increased in the dexamethasone-treated group.
Conclusions:
- Prenatal dexamethasone administration partially restored disaccharidase activity in a fetal gastroschisis model.
- Dexamethasone shows potential for improving intestinal function in gastroschisis.
- Further research is warranted to explore clinical applications.
Abstract:
Infants with gastroschisis experience delayed intestinal motility and absorption for several weeks after birth. This intestinal dysfunction is believed to occur primarily in the third trimester and to be largely caused by the prolonged exposure of the intestine to amniotic fluid. Previous studies have shown that prenatal steroid administration will enhance mucosal disaccharidase activity and nutrient uptake. The present study evaluates the effects of dexamethasone on intestinal function in a rabbit fetal gastroschisis model. Thirty-four fetuses from 10 New Zealand white rabbits were divided into three groups: (1) gastroschisis group (GSC, n = 10), gastroschisis was created on gestational day (GD) 24 (term = 31 to 33 days); (2) dexamethasone group (GSD, n = 10), after the creation of gastroschisis, a small osmotic pump was placed into the rabbit doe for dexamethasone infusion into the fetal amniotic cavity for 7 days (0.2 microgram/g/d); (3) normal group (NF, n = 10), unoperated littermates from the GSC group. There were no maternal deaths, and fetal survival rate was 85%. The fetal small intestinal disaccharidase enzyme, lactase (UE/g protein), was markedly decreased in GSC fetuses. It was increased 70% in the GSD group but lower than in normal fetuses (GSC = 10.0 +/- 1.6; GSD = 17.3 +/- 1.6 [GSD versus GSC, P < .05]; NF = 48.0 +/- 6.7). Maltase activity in the GSD group was significantly increased (GSC = 7.2 +/- 1.1; GSD = 13.9 +/- 1.8 [GSD versus GSC, P < .05]; NF = 12.2 +/- 1.3).(ABSTRACT TRUNCATED AT 250 WORDS)