[Dynamic studies of the leukocyte phagocytic activity after exposure of rats to asbestos and basalt fibers]. / Dynamische Studien der phagozytären Leukozytenaktivität nach der Exposition von Asbest- und Basaltfasern bei Ratten.

The paper presents the results of the dynamic one-year follow-up of the phagocytic activity of Wistar-rats peripheral blood leukocytes following intraperitoneal administration of asbestos and basalt fibres (Man-Made Mineral Fibres--MMMF). We investigated the phagocytic activity of leukocytes in peripheral blood following intraperitoneal administration of asbestos and basalt fibres to rats 2, 24, 48 h as well as 1, 2, 4, 8 weeks and 6 and 12 months after dosing. We investigated the time dependent of the changes of relative granulocytes count, percentage of phagocytizing cells from leukocytes, percentage of phagocytizing granulocytes and percentage of phagocytizing monocytes. The results of our experiment showed that asbestos and basalt fibres differed in their effects on the parameters studied. Granulocyte count as well as the phagocytic activity of leukocytes during the one-year dynamic follow-up in both dust--exposed groups of animals were found to change in two phases, characterised by the initial stimulation of the acute phase (I), followed by the suppression of the parameters in the chronic phase (II). Exposure to asbestos and basalt fibres led, in phase II, to impairment of the phagocytic activity of granulocytes. Asbestos fibres at the same time significantly decreased also the phagocytic activity of monocytes. Exposure to basalt fibres did not affect the phagocytic activity of monocytes in phase II. It follows from the results of the experiment, that the monocytic component of leukocytes probably plays an important role in the development of diseases caused by exposure to fibrous dusts and basalt fibres have smaller biological effects compared with asbestos fibres.