Related Experiment Videos
Expression of intestinal ornithine decarboxylase during postnatal development in neonatal rats
Chuan-Hao Lin1, Roy Vijesurier, Ye-Shih Ho
1Department of Pediatrics, Division of Gastroenterology and Nutrition, Wayne State University and Children's Hospital of Michigan, 3901 Beaubien Blvd., Detroit 48201, USA. lchuan@med.wayne.edu
Insights
Postnatal development in rats shows increased ornithine decarboxylase (ODC) activity and sucrase activity, indicating intestinal maturation. This ODC induction appears regulated by post-transcriptional events, not mRNA changes.
Area of Science:
- Gastroenterology
- Developmental Biology
- Biochemistry
Background:
- Ornithine decarboxylase (ODC) is crucial for intestinal growth and maturation.
- Regulatory mechanisms of intestinal ODC during postnatal development require further elucidation.
Purpose of the Study:
- To investigate the mechanisms of intestinal ODC expression during postnatal development in rats.
- To correlate ODC activity with intestinal maturation markers like sucrase activity.
Main Methods:
- Collected rat small intestinal mucosa from postnatal days 10 to 30.
- Assayed ODC and sucrase activities.
- Measured ODC mRNA and protein levels.
Main Results:
- Sucrase activity increased significantly after postnatal day 19.
- ODC activity showed a sharp increase from day 19, peaking on day 24.
- ODC protein levels mirrored ODC activity, while ODC mRNA remained relatively constant.
Conclusions:
- Intestinal ODC activity induction coincides with increased sucrase activity, a marker of maturation.
- ODC induction during postnatal development likely involves post-transcriptional regulation or other cellular mechanisms.
- Understanding polyamine biosynthesis regulation aids small intestine maturation insights.
Abstract:
Ornithine decarboxylase (ODC) has been shown to play an essential role in intestinal growth and maturation in rats. However, the regulatory mechanisms have not been fully elucidated. We studied the mechanisms of expression of intestinal ODC during postnatal development. Rat small intestinal mucosa was obtained from postnatal days 10, 15, 17, 19, 21, 24 and 30. Intestinal mucosa was assayed for ODC and sucrase activities. In addition, intestinal ODC mRNA, and ODC protein levels were also measured. The results showed that the intestinal sucrase activity was low before postnatal day 19. The sucrase activity then increased steadily from day 19 up to day 30. Intestinal ODC activities remained low from postnatal day 10 to day 17. A sharp increase in ODC activity was noted on day 19, which peaked on day 24 (a 20-fold increase from its low basal level) and declined on day 30. Intestinal ODC proteins followed the same pattern of postnatal expression as that of ODC activity. In contrast, ODC mRNA did not show significant change throughout the study period. The possible mechanisms by which intestinal ODC mRNA levels remain practically unchanged during postnatal development are discussed. We conclude that the ontogenic increase in sucrase activity, a marker for intestinal maturation, occurs at the same time to that of the induction of ODC activity. We also suggest that the induction of intestinal ODC activity during postnatal development is the result of post-transcriptional events or other cellular mechanisms. A better understanding of the regulation of polyamine biosynthesis during postnatal development of the small intestine will provide insights contributing to the maturation of the small intestine.