PERIPHERAL-BLOOD OF THE RANA FROGS AS A T EST-SYSTEM FOR ASSESSMENT OF ENVIRONMENTAL-POLLUTION

Differential analysis of leukocytes was carried out peripheral blood s mears of the frogs from four localities in the territory adjacent to a chemical plant in the Novgorod District (Rana temporaria) and two lac lities with an increased radiation background in the Bryansk District (R. lessonae and R. esculenta). Marked and similar changes in the cont ent of neutrophilic and eosinophilic granulocytes were found in the fr ogs from all studied localities. A pronounced neutropenia was noted, w hich was often accompanied by the appearance of immature forms of the neutrophilic series. We propose that these changes are due selective d amage of the entire series of differentiation of neutrophilic granuloc ytes, including the precursor cells. The increased percentage of eosin ophilic granulocytes and appearance, in some cases, of immature cells are considered as signs of protective (antitoxic and antimicrobial) re sponse.