[Influence of passive smoking associated with exercise performed by rats during pregnancy and lactation on their offspring growth].

Purpose: the purpose of this study was to evaluate mortality, weight and body length, and the gastrocnemius muscle of the offspring of pregnant rats submitted to a swimming program associated with second-hand smoke.

Methods: twenty-four rats were divided into four groups: GF (exposed to cigarette smoke), GC (control), GFN (submitted to the swimming program and exposed to cigarette smoke), and GN (submitted to the swimming program). The mortality, weight and length of the offspring were measured at four time points. The gastrocnemius muscle of the pups was obtained for evaluation of muscle development.

Results: the average number of offspring was lower for GF (10.2) and GFN (10.3) and higher for GN (12.8). At birth, only GFN showed significantly lower weight (p=0.016) and length (p=0.02), whereas during lactation the groups exposed to cigarette smoke showed significantly lower weight. GFN had delayed muscle development compared to GC (p=0.03).

Conclusions: Passive smoking during pregnancy and lactation negatively influenced number, weight and body length of offspring from birth to weaning and muscle development, and the swimming program positively influenced these variables at birth, although it did not provide the same benefits during lactation; and their association negatively affected these measures.