Background. The mechanism by which tracheal occlusion (TO) induces lung growth is unknown. The sonic hedgehog (Shh) is a signaling protein essential for bronchial branching and lung maturation in rats. Shh expression is delayed in nitrofen-induced congenital diaphragmatic hernia (CDH). The aim of this study was to see if TO could up-regulate Shh expression in CDH. / Methods. To create CDH in fetal rats, time-dated pregnant rats were gavaged 100 mg of nitrofen on day 9.5 post-conception. TO was performed on day 19 of gestation (term=22 days). Animals were sacrificed on day 20 and 21. Lung growth was measured by lung to body weight ratio (LW/BW) and histology. The expression of Shh was measured by immunohistochemistry (IHC) and by quantitative real time polymerase chain reaction (qRT-PCR). / Results. TO induced growth in nitrofen-affected lungs in comparison to controls. Higher levels of Shh mRNA expression were observed in the nitrofen-affected lungs on day 21. TO in the nitrofen-affected animals lowered the mRNA expression levels and brought them to control levels. / Conclusions. The nitrofen-induced hypoplasia of CDH is reversible with TO. Shh-mRNA expression in the nitrofen-affected lungs is delayed and peaks later during gestation. TO decreases Shh-mRNA expression levels and brings them to control levels.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.98737 |
| Date | January 2006 |
| Creators | Khan, Nasir. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Division of Surgical Research.) |
| Rights | © Nasir Khan, 2006 |
| Relation | alephsysno: 002332466, proquestno: AAIMR24707, Theses scanned by UMI/ProQuest. |
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