Experimental study of toxic effects of cadmium against background of physical exercise

Introduction. Nowadays, working conditions in industry are often associated with chemical exposure along with manual labour. Given the evidence of the combined effect of heavy metals and muscular work, an increase in cadmium toxicity can be expected. However, an experimental study and actual assessment of exposure to both factors are necessary to avoid underestimation or overestimation of real risks.

The purpose of our study was to establish health effects of subchronic cadmium toxicity against background of physical exercise.

Materials and methods. In a subchronic animal experiment, four groups of outbred male rats, 14 animals each, were exposed to cadmium chloride at a single dose of 0.77 mg/kg body weight, forced physical exercise (treadmill running), both factors combined, or acted as a control group. Hematological, biochemical, and morphometric indices in rodents were assessed at the end of the experiment. The statistical significance of differences between the groups was established using Student’s t-test (p<0.05). For mathematical modelling, we used the Response Surface Methodology (RSM) with the construction of Loewe isoboles.

Results. We observed significant unfavorauble shifts in 27.5% of the assessed morphometric, hematological, biochemical, cytological, and histomorphometric indices in rats following the exposure to cadmium only and in combination with exercise. The mathematical analysis based on the response surface modelling showed the typology of the combined impact of chemical and physical factors to vary depending on the specific effect by which it is assessed, as well as on the dose and level of effect.

Limitations. Laboratory animals of only one biological species and sex were used for the experiment, exposed to a single concentration of cadmium and physical exercise of only one intensity level.

Conclusion. The principles of health effects of cadmium and physical stress as risk factors of the workplace environment specified in the in vivo experiment may serve as a basis for scientific justification of risk assessment criteria to avoid under- or overestimation of real risks in the occupational setting.

Compliance with ethical standards. Ethics approval was provided by the Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (protocol No. 4 of September 30, 2022).

Contribution:
Minigalieva I.A., Ryabova Yu.V. – study conception and design;
Shabardina L.V., Ryabova Yu.V., Kungurtseva A.K., Sakhautdinova R.R. – data collection and processing;
Panov V.G. – statistical data analysis;
Shabardina L.V., Panov V.G., Kungurtseva A.K., Sakhautdinova R.R. – figure preparation;
Shabardina L.V., Ryabova Yu.V. – draft manuscript preparation;
Minigalieva I.A. – scientific editing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: June 20, 2024 / Accepted: July 31, 2024 / Published: September 10, 2024