Turkish Neurosurgery 2009 , Vol 19 , Num 3
High Dose Cotinine may Induce Neural Tube Defects in a Chick Embryo Model
Ali DALGIÇ1, Ercan ARMAĞAN2, Fatma HELVACIOĞLU3, Önder OKAY4, Ergun DAĞLIOĞLU5, Gülnur TAKE6, Ağahan ÜNLÜ7, Deniz BELEN8
1,4,5,8Ankara Numune Educational and Research Hospital, II. Neurosurgery Clinic, Ankara, Turkey
2,7Ankara University, School of Medicine, Department of Neurosurgery, Ankara, Turkey
3,6Gazi University, School of Medicine, Department of Histology and Embryology, Ankara, Turkey
AIM: Nicotine is a well-known agent among 4000 chemicals in cigarettes. About 70 to 80% of nicotine is converted to cotinine, a major metabolite. The aim of the present study is to investigate the effect of cotinine on neural tube development in a chick embryo model.

MATERIAL and METHODS: Sixty fertile, specific pathogen free eggs were divided into 6 groups for this study. In the first group, a fixed cotinine concentration for each egg was calculated just to simulate the concentration of a smoker's blood level. A second experimental group was designed at a higher cotinine concentration. Embryos that succeeded to reach Hamburger-Hamilton stage 12 from each group were then embedded into paraffin for permanent sections. These two groups were compared with eggs subjected to vehicle (standard alcohol and ten times more alcohol concentration) and control groups (saline and sham groups).

RESULTS: Embryos of the cotinine (regular dose), vehicle and control groups were normal, but embryos subjected to higher cotinine concentrations were malformed at the cranial part of the thoracic neural tube.

CONCLUSION: Association of cotinine with neural tube defects was demonstrated in the present study. Cigarette smoking may induce hazardous effects on neural tube development. Keywords : Nicotine, Cotinine, Chick embryo, Neural tube defect, Congenital malformation

Corresponding author : Ali Dalgıç, alidalgic@yahoo.com