Evaluation of histological changes after tracheal occlusion at different gestational ages in a fetal rat model

Author(s)

Gallindo, Rodrigo Melo ^[1] ; Lanhellas Goncalves, Frances Lilian ^[1] ; de Resende Barreto, Carolina Teixeira ^[2] ; Santos Schmidt, Augusto Frederico ^[3] ; Violin Dias Pereira, Luis Antonio ^[4] ; Sbragia, Lourenco ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Surg & Anat, Div Pediat Surg, Ribeirao Preto, SP - Brazil

^[2] Univ Estadual Campinas, UNICAMP, Sch Med Sci, Dept Obstet & Gynecol, Campinas, SP - Brazil

^[3] Cincinnati Childrens Hosp Med Ctr, Dept Pediat, Cincinnati, OH - USA

^[4] Univ Estadual Campinas, UNICAMP, Dept Histol & Embryol, Campinas, SP - Brazil

• Document type: Journal article
• Source: Clinics; v. 68, n. 1, p. 59-63, 2013.
• Web of Science Citations: 2

Abstract

OBJECTIVES: To evaluate the histological changes of tracheal cartilage and epithelium caused by tracheal occlusion at different gestational ages in a fetal rat model. METHODS: Rat fetuses were divided into two groups: a) External control, composed of non-operated rats, and b) Interventional group, composed of rats operated upon on gestational day 18.5 (term = 22 days), divided into triads: 1) Tracheal occlusion, 2) Internal control and 3) Sham (manipulated but not operated). Morphological data for body weight, total lung weight and total lung weight/body weight ratio were collected and measured on gestational days 19.5, 20.5 and 21.5. Tracheal samples were histologically processed, and epithelial, chondral and total tracheal thicknesses were measured on each gestational day. RESULTS: The tracheal occlusion group exhibited an increase in total lung weight/body weight ratio (p<0.001). Histologically, this group had a thicker epithelial thickness (p<0.05) and thinner chondral (p<0.05) and total tracheal thicknesses (p<0.001). These differences were more prominent on gestational days 20.5 and 21.5. CONCLUSION: Tracheal occlusion changed tracheal morphology, increased epithelial thickness and considerably decreased total tracheal thickness. These changes in the tracheal wall could explain the development of tracheomegaly, recently reported in some human fetuses subjected to tracheal occlusion. (AU)

• FAPESP's process: 11/12587-0 - Evaluation in vivo of the effect of corticosteroids and ventilation in oxide nitric pathway on the expression of VEGF and its pulmonary receptors after fetal tracheal occlusion in the congenital diaphragmatic hernia in rats
• Grantee: Frances Lilian Lanhellas Gonçalves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/00794-1 - Assessment of nitric oxide (NO) in vivo after fetal tracheal occlusion on the expression of VEGF receptors in pulmonary congenital diaphragmatic hernia induced by Nitrofen
• Grantee: Lourenço Sbragia Neto
• Support Opportunities: Regular Research Grants