1-METHYL-2-PYRROLIDONE (NMP) - REPRODUCTIVE AND DEVELOPMENTAL TOXICITY STUDY BY INHALATION IN THE RAT

A two-generation reproduction study with a developmental toxicity comp onent was conducted. For the reproduction phase, male and female rats inhaled 0, 10, 51, or 116 ppm NMP daily for 6 hr/day, 7 days/week from 34 days of age to the end of the mating period for the males (100 exp osure days) and till weaning for the females (about 143 exposure days, but interrupted from Day 20 of gestation to Day 4 Postpartum). On Day 70 postpartum, one male and one female selected from each litter late r mated with newly obtained, nonexposed adults of the opposite sex to produce an F2 generation. For the developmental phase, rats of both se xes inhaled 0 or 116 ppm NMP as outlined above, but euthanization of t he females occurred on Day 21 of gestation followed by fetal examinati on for structural alterations. The indices of reproductive performance for the NMP-exposed rats did not differ significantly from those obta ined for the control rats. Rats exposed to 116 ppm had a detectable de crease in response to sound. No other signs of NMP-related toxicity we re detected among the parental rats. An exposure-related but slight de crease in fetal weight was detected only among the F1 offspring whose parents both inhaled NMP at 116 ppm. This slight effect also appeared at birth among the pups of the reproductive phase where it persisted t ill 21 days after birth when NMP inhalation by the mother ceased. Ther eafter, the body weight of the offspring was comparable to the control values. No detectable or developmental effects appeared in the 10 or 51 ppm groups.