The effect of six weeks of aerobic training on serotonin and serotonin receptors levels in hippocampus of depression female BALB/c mice with breast cancer

Aerobic exercise has proven benefits in reducing the incidence of cancers. In this study we evaluated the effect of aerobic training on serotonin and serotonin receptors levels in hippocampus of female BALB/c mice depressed suffered from breast cancer.

Thirty mice were randomly divided into healthy control, cancer control, exercise cancer groups. Breast cancer tumors were induced by MC4-L2 cell infusion. Aerobic exercise group were performed treadmill exercise (5 times/week for 6 weeks with duration and intensity of 55min/d and 20m/min respectively in the final weeks). For investigation the depression in this study we used force swim test (FST) before and after training. Forty eight hours after the last exercise session hippocampus tissue samples were obtained. Concentrations of serotonin (pg/ml), 5˗HT3R and 5˗HT7R were measured by Elisa and RT˗PCR methods respectively. 

Statistical analysis show that significantly increase serotonin levels in exercise cancer group (P=0.001). The mean 5˗HT3R and 5˗HT7R level of the cancer groups were not significantly than that of the healthy control group (p=0.689) and exercise cancer group (p=0.415). The amount of immobility time was significantly lower in the exercise cancer group compared to that in the cancer control group (P=0.001).

In conclusion, breast cancer can lead to reduction of serotonin levels in the hippocampus and increase depression. Also, six weeks of aerobic exercise can increase serotonin level in the hippocampus of the breast cancer mice but on 5HT3 and 5HT7 receptors were not significant. Six weeks of aerobic exercise can decrease depression. More studies are suggested.