Abstract
The percentage of cells with strongly peroxidase positive granula among pseudoeosinophile leucocytes increased remarkably and reached the maximum 2 days after the first administration of morphine. Then it showed a decrease and approached the initial on the 5th day of experiment. The percentage of the cells with Giemsa-stained granula among pseudoeosinophile leucocytes increased in number and reached the maximum 5-6 days after the first injection of morphine hydrochloride. It decreased and approached the initial on the 10th day of experiment.