Integral indicators of cardiotoxicity of lead and cadmium on the background of physical activity

Abstract

Introduction. Modern metallurgical production is characterized by mixed exposure of workers to harmful chemicals, of which lead and cadmium are the most common. A high physical workload is yet another occupational risk factor for metallurgists. Objective. Experimental study of effects of lead or cadmium and physical load on integral indicators of cardiotoxicity in rats. Materials and methods. We have carried out two 6-week experiments on rats to study integral indicators of cardiotoxicity of lead or cadmium and their changes under effect of physical activity. Solutions of lead or cadmium salts were administered intraperitoneally three times a week. Physical workload was simulated on a treadmill (10 min/day, 5 days a week). At the end of the experiment, electrocardiogram and blood pressure parameters were registered non-invasively. Results. Lead and cadmium had a cardiotoxic effect manifested by ECG changes. No pronounced hemodynamic changes were observed in our studies. According to ECG parameters, physical load slightly mitigates cardiotoxic effects of lead, but enhances manifestations of cadmium toxicity. Limitations. Data comparison can be affected by the fact that both outbred and inbred rats were used in the experiments. Caution should be taken when extrapolating animal data to humans since electrophysiological processes in the work of the heart differ in small rodents and large mammals. Conclusion. The established ambiguity of the impact of the physical workload on cardiotoxic effects of heavy metals necessitates further studies of this problem.