This study aimed to explore the effects of exogenous element exposure via the respiratory tract on the Se, Cd and Mo concentrations in different components of the peripheral blood in rats as well as to determine the correlations of the three trace elements concentrations among the components. The Sprague-Dawley rats were randomly divided into a control group and several experimental groups treated with different doses. The rats were exposed to a mixed trace element solution through 10 days of intratracheal instillation. The whole blood of all rats was collected and separated into three parts with Percoll density gradient centrifugation. The Se, Cd and Mo levels in whole blood, plasma, red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs) were determined by inductively coupled plasma mass spectrometry. The concentrations of the three trace elements increased together with the increase of the given doses (P<0.05), except Cd and Mo in the PBMCs. The three trace elements lacked linearity with the exposure doses in the PBMCs (r, 0.249-0.508), while the opposite was the case for the other components of the peripheral blood (r, 0.806-0.934). The correlation coefficients were higher (0.842-0.962) among the whole blood, plasma and RBCs than between PBMCs and other components, such as Se (0.376-0.529), Cd (0.495-0.604) and, especially, Mo (0.160-0.257). In conclusion, PBMCs might provide information about endogenous factors, and whole blood could more accurately reflect the effects of exogenous factors compared to other blood components.
Keywords: Sprague-Dawley rats; Trace elements; percoll density gradient centrifugation; peripheral blood mononuclear cell.