Contact:
Dr. James Fewell, University of Calgary, 
(403) 220-4513 or fewell@ucalgary.ca
 

PRENATAL EXPOSURE TO NICOTINE MAKES RATS ALTERS THE RESPONSE OF ADULT RATS TO A STRESSOR OF EVERYDAY LIFE

One in every four American women continues to smoke cigarettes during pregnancy despite warnings this might affect their babies.   A study of rats suggests one previously unsuspected way that prenatal exposure to nicotine may alter a baby's response to stressful situations even as an adult.

Dr. James Fewell and colleagues, University of Calgary, exposed 23 male and 25 female newborn rat pups to nicotine from day six or seven of gestation until 21 days after birth.  Nicotine levels were comparable to what a fetus would experience if its mother continued to smoke at a fairly high level.  The adult rats were then exposed to a novel environment, a moderately high level "stressor" in a rat's life, as measured by their stress hormone - corticosterone - response. On being taken from the safety of their home cage and being exposed to a simulated open field, the rats which had been exposed to nicotine during fetal development had an attenuated core temperature response compared to rats which had been exposed to a placebo during fetal life.  This would indicate that fetal exposure to nicotine alters one component of the bodies' response to a "stressor" of every day life.  The consequences of this altered thermogenic response remain to be determined.