| dc.description.abstract | Pregnant rats were administered nicotine (0.6
mg/kg/day) during different stages of pregnancy.
Exposure occurred in either the first trimester (days
1-7), second trimester (days 8-14), third trimester
(days 15-21), throughout gestation, or not at all
(nonexposed controls). The effects of prenatal nicotine
exposure on reproductive, developmental and reflex
indices were studied. Prenatal nicotine exposure
resulted in the birth of smaller sized litters for
first trimester exposed dams, as compared to all other
groups, except third trimester exposed females. Third
trimester exposed females gave birth to smaller litters
than second trimester and control females. Total
weights of litters from third trimester females were
lower than second trimester and control females.
Furthermore, developmental age for eye opening was
found to be earlier for first trimester animals as
compared to third trimester or control rats. Also,
animals exposed throughout gestation showed eye opening
earlier than controls. Finally, first trimester exposed
animals acquired the righting reflex sooner than all
other groups except nonexposed control rats. Control
animals demonstrated this reflex earlier than second or
third trimester exposed rats.
Prenatal nicotine exposure, in this study, did not appear to influence the acquisition or extinction of
behaviorally conditioned immunosuppression in adult
rats. The implications of this, regarding nicotine
dose, the specific area of the immune system examined,
and the developmental age of the subjects, are
discussed. | |
