CADMIUM EXCRETION IN FECES OF RATS AT EXPERIMENTAL CONDITIONS

摘要

Studies demonstrated that the excretions per 1 gof rat weight inthe experimental group usually prevails over the? control group, especially in the second part of the experiment. The increase in the amount of feces in animals of the experimental group was also registered. Such processes may indicate the intense excretory processes and? increase the output of harmful? pollutants from the rats? together with overall stimulation of rat digestive activity. The higher correlations between Cd and other pollutants, namely toxic Ni and Pb (r = 0.84 and 0.91, respectively) were calculated for rat feces of experimental group compared to the control. The concentration of Cd and Pb in the excretion of experimental group was maximal in the first day of the experiment, suggesting definite reaction towards rapid output of maximum amount of toxicants from rat body. Subsequently, a decrease in concentration of other pollutants demonstrated their incorporation in metabolic processes and significant accumulation in rat body (kidney and liver), or involvement of other mechanisms for neutralization and removal of intoxicants. Given the increasing amount of excretions? in the second half of the experiment, this may be a solution to this issue. The Cd output per 1 g of rat weight was maximal in the first day, followed by a rapid decline and partial restoration in second half of the experiment. Obviously, it confirms the theory of substitution mechanisms in excretion of significant amount of hazardous toxicants and shifting towards less concentrated excretions in greater amount. Thus, the correlation index between the percentage of excreted pollutant and its concentration in the excretion was 0.75. When we considered only the first 7 days this increased to 0.91 and proved that during the first stage of experiment the percentage of pollutants excretion was dependent upon its concentration in feces. Correlation between Cd output rate and excretion volumes was insignificant (0.08 for the complete experiment) but was increased sharply during the second half of the experiment – up to 0.70. This contributes to the theory that the volume of Cd output in the initial stage of experiment was determined by the concentration of other pollutants in feces, while in second half by the amount of excretions. Keywords: cadmium, output, excretion, concentration, correlation.