[Evaluation of the effect of a swimming training program on levels of lung hypoxia inducible factor-1 alpha [HIF-1 alpha] in pups of mother rats exposed to cadmium]

Cadmium is one of the most important biological contaminants that its intake in pregnancy causes disease and malformations in the mother and baby. This study was done with the aim of evaluating the effect of maternal regular swimming training and oral cadmium intake during pregnancy on the levels of lung hypoxia inducible factor-1alpha [HIF-1 alpha] in pups. In this study, 32 female wistar rats weighting 200 +/- 20g, after 2 weeks of familiarity with the new environment and pregnancy were divided into four groups of 8, including: 1- cadmium, 2- swimming, 3- cadmium-swimming, and 4- control. Swimming training started from the first day of pregnancy and continued once a day [5 days per week] until delivery day. Intake dose of cadmium was 400mg/l in drinking water. HIF-1alpha concentration of Lung was determined with enzyme-linked immunosorbent assay [ELISA] method. The data were analyzed by one-way analysis of variance and Holm-Sidak tests at significance level of p<0.05. The mean weight of pups in cadmium group showed a significant decrease [p<0.001] compared to the control group. Also, the pups' lung HIF-1 alpha levels significantly [p<0.001] increased in the swimming group and significantly [p<0.001] reduced in cadmium group compared to control group. These results indicated the effect of swimming training on the increase of lung HIF-1 alpha levels in pups that their mothers were swimming regularly in pregnancy. Accordingly, it seems submaximal swimming training in pregnancy can modify its negative effects on the fetal lungs through compensating of cadmium-induced decrease in HIF-1 alpha

[ effect of pregnant rat swimming on hypoxia-inducible factor-1 alpha levels of neonatal lung]

Uterine environment and fetal period can profoundly affect health of the neonat. Hypoxia-inducible factor-1 alpha [HIF-1 alpha] is a transcription factor that regulates cellular stress responses and its activity is essential in both embryogenesis and postnatal life. The aim of the present study was to investigate the effects of maternal swimming on rat pups' HIF-1 alpha levels as a key regulator of oxygen in lungs. Sixteen female Wistar rats weighing 180- 200 grams were acclimated to a new environment consisting of equal light-darkness cycle and ad lib access to chow and adapted to the stress caused by water for two weeks. The rats were divided into two swimming and control groups. Swimming training began on the first day of pregnancy in a pool and continued for 3 weeks [1 h/day, 5 days/wk]. Pups' lungs were removed two days after birth and their HIF-1 alpha concentration was determined with enzyme-linked immunosorbent assay [ELISA]. Statistical analysis of the data was done using independent t-test. A p-value smaller than 0.05 was considered statistically significant. Swimming lead to a significant [P<0.001] increase in the pups' lung HIF-1 alpha levels compared with the control group. Although 3-wk period of swimming training, showed no significant increase in weight and also lung weight of newborns. Thus it can be concluded that swimming endurance training in pregnancy, can be considered as appropriate alternative in order to embryos development. Our research suggests that HIF-1 alpha level is an essential element for the development of the lungs of embryos. Moreover, further studies on the lung HIF-1 alpha levels at post-natal period with different modes of exercise will provide more clear insight into the mechanisms of the findings resulting from this study