Effect of nicotine exposure during pregnancy and lactation on maternal, fetal, and postnatal rat IGF-II profile.
Smoking during pregnancy has been shown to result in an increased risk of low birth weight. However, the mechanisms underlying this association are poorly understood. The insulin-like growth factor (IGF) system plays a critical role in the regulation of feto-placental growth and development, and abnormal processing of proIGF-II may alter its biological function. Our goal was to investigate the effects of exposure to nicotine on maternal, fetal, and neonatal IGF-II processing. Nulliparous female Wistar rats were randomly assigned to receive saline (vehicle) or nicotine bitartrate (1 mg x kg(-1) x d(- 1)). After mating, dams were euthanized at embryonic days 15, 18, and 21, and fetal body weight was recorded. Serum (fetal and maternal) was collected for determination of the IGF-II profile by Western blot analysis. Nicotine exposure prevented the decrease in maternal IGF-II processing seen in controls with advancing gestation. However, there was no influence of nicotine on fetal levels of IGF-II. Postnatally (postnatal day [PND] 21), pups exposed to nicotine in utero had decreased levels of big IGF-II. Our results show, for the first time, that nicotine exposure prevents the decrease of IGF-II processing in the maternal compartment. This may represent a compensatory mechanism allowing the mother to counteract the negative influence of nicotine on fetal growth and development. Our postnatal findings of suppressed IGF-II may help explain some of the long-term health complications seen in individuals exposed to smoking in utero.
Gruslin
Andrée
A
Division Maternal-Fetal Medicine, Department OBS-GYN and Newborn Care, The Ottawa Hospital University of Ottawa, Ontario, Canada. agruslin@ottawahospital.on.ca
Cesta
Carolyn E
CE
Bell
Michael
M
Qing Qiu
Petre
Maria A
MA
Holloway
Alison C
AC
D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D005260:Female; D047109:Fetal Development / Q000187:drug effects; D005317:Fetal Growth Retardation / Q000097:blood / Q000139:chemically induced* / Q000503:physiopathology*; D005865:Gestational Age; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D007774:Lactation; D009538:Nicotine / Q000633:toxicity*; D018722:Nicotinic Agonists / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000097:blood / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar
D018722:Nicotinic Agonists; D007335:Insulin-Like Growth Factor II; D009538:Nicotine