The Effect of Endurance Swimming Exercise Training on Structural Remodeling and Apoptotic Index of Adrenal Cortex in Pregnant Rats Exposed to Cadmium Toxicity

The purpose of this study was to investigate the effect of endurance swimming exercise training on structural remodeling (volume and parenchymal cell number) and apoptotic index of adrenal gland in pregnant rats exposed to cadmium poisoning.
A total of 32 pregnant rats weighing 200 ± 20 g were randomly divided into four groups of control, cadmium, swimming, and cadmium-swimming. Cadmium dissolved in drinking water was administered to treatment groups, available ad libitum during pregnancy. Swimming exercises 5 days/week and 60 min/day were performed from the first day of gestation until the end of the period. Two days after delivery, the mothers were sacrificed and their adrenal glands were removed. After stabilizing the samples, Hematoxylin-Eosin staining and TUNEL assay were performed, and the number of necrotic and apoptotic cells in 10 microscopic fields was counted randomly. The size of various regions of the adrenal gland and total number of parenchymal cells were estimated using stereological methods. Data were analyzed by two-way ANOVA under SPSS software (version 21).
Cadmium poisoning caused extensive bleeding and tissue destruction in the adrenal gland of the pregnant mothers, but endurance training reduced the amount of bleeding. Cadmium poisoning during pregnancy decreased the total volume of the gland, the volume of the cortical part and its different layers as well as the number, size and function of parenchymal cells in all three cortical zones, especially the fasciculata zone. Performing swimming exercise training in this condition worsened the structural state of the gland and led to a further reduction in the number of parenchymal cells within all three parts of the adrenal gland.
Exercise training in determined intensity increased the structural and morphological complications of cadmium toxicity in the adrenal gland of pregnant rats. So, pregnant mothers are advised to use low-intensity exercises and trainings.