Cardiac microstructure in female and male offspring of exercised rat mothers.

The microstructure of the cardiac muscle in eight subgroups of female and male rats was investigated: exercised (EE) and control (EC) offspring of exercised mothers, and exercised (CE) and control (CC) offspring of control, inactive mothers. The differences between subgroups were subjected to variance analysis and multiple-range tests according to Duncan. There were no marked differences in total body weight and weight of the heart related to total body weight. A significant difference (highest values) was shown in the density of muscle fibers and capillaries in the offspring of exercised mothers, which was further potentiated by the additional exercise during postnatal life. Diffusion distance was significantly longer in CC animals; the other subgroups did not differ significantly. There were no significant differences in the reaction of female and male offspring both due to prenatal and postnatal exercise.