THE effects of chronic mild prenatal stress on leukocyte infiltration into
the airways was investigated in rat offspring. The chronic prenatal stress
consisted of transitory and variable changes in the rat's living conditions
. Offspring at adult age were actively sensitized (day 0) and intratracheal
ly challenged (day 14) with ovalbumin. Bronchoalveolar lavage was performed
in the offspring at 48 h after intratracheal challenge with ovalbumin. A s
ignificant increase in total leukocyte infiltration was observed in the non
stressed offspring group and this was associated with a marked recruitment
of eosinophils without a significant effect on the influx of neutrophils an
d mononuclear cells. In the prenatal stressed offspring, the counts of both
total leukocyte and eosinophils, as well as mononuclear cells, was increas
ed by 50% compared to the non-stressed offspring. We provide here the first
experimental evidence that chronic mild unpredictable prenatal stress prod
uces a marked increase in the allergen-induced airway inflammation in the r
at offspring.