Optical and Morphometric Parameters of Neutrophils in Rats Exposed to Copper-Zinc Pyrite Ore

The method of computer morphometry allows us to study in detail both the morphometric features of neutrophils and their optical properties. The refractive index of cytoplasmic components directly depends on the cytoplasm’s granularity and the presence or absence of organelles and inclusions, while the refractive index of chromatin depends on its structural ordering. Considering this, morphometric and optical parameters can serve as markers of the functional and metabolic activity of neutrophilic leukocytes when exposed to adverse environmental factors. The purpose of the research was to investigate the morphometric and optical characteristics of rat neutrophils at different stages of exposure to copper-zinc pyrite ore. Materials and methods. The experiment involved 68 nonlinear male rats aged 3–4 months (mean weight 210.5 ± 10.5 g), which were divided into the control and 3 experimental groups based on the duration of exposure to the ore (20, 45 and 60 days). Morphometric and optical parameters of neutrophils were determined by computer morphometry using the MECOS-C2 automatic microscopy complex (Russia) for smear analysis installed on the AXIO Lab.A1 microscope (ZEISS, Germany). Results. During all stages of the experiment, the total cell area and the cytoplasmic area of neutrophils was decreasing along with the optical density of the cytoplasm and nucleus. Statistically significant negative correlations between the area and optical density of the nucleus were recorded throughout the experiment. The decreased optical density of the neutrophil cytoplasm under the influence of ore indicates a declining number of granules in the cytoplasm, while the decreased optical density of the nucleus indicates a growing proportion of decondensed chromatin. The reduction in cytoplasm optical density in all spectral components, combined with a decrease in cytoplasmic area, is due to a sharp weakening of the functional capabilities of neutrophil granulocytes under the action of ore. The reduction in the optical density of neutrophil nuclei is, apparently, associated with the functional reorganization of chromatin, i.e. with the conversion of facultative heterochromatin into euchromatin.