Morphometric analysis of fetal rat lung after the administration of Pyralene-3000.

The effects of the application of commercial low chlorinated PCB Pyralene-3000 on rat lung development during late gestation were studied. In the developing lungs (17.5 to 21.5 days) the volume density (Vv) of a particular compartment and length density of potential air spaces (Lv) were determined. Significant difference (p < 0.01) in epithelium to mesenchyme ratio (Epi/Mes) occurred between the control and treated groups on day 20.5 due to an increased volume proportion of mesenchyme (Vvmes) in the treated group suggesting a small delay in maturation. Decreased volume proportion of potential airspaces (Vvair) was observed on days 18.5 and 20.5. However, no differences were found on day 21.5 in any variables studied.