Tetrahymena pyriformis in the ciliate mobility test. Validation and description of a testing procedure for the registration of harmful substances in the air as well as the effects of cigarette smoke on the human respiratory ciliated epithelium

The damage of the human respiratory ciliated epithelium or its ciliar activ ity caused by mixtures of harmful substances in the air and cigarette smoke is a considerable parameter for the judgement of acute harmful influences on the human respiratory tract. As an immediate measuring or a quantitative statement about the influence o n cilia in vivo at human beings is extremely difficult and problematic, a c onvenient model experimental system in form of the so called ciliate mobili ty test (CMT) has been used. In this connection the influence on cilia of t he protozan single-celled organism Tetrahymena pyriformis, regarding its av erage speed of locomotion has been taken as standard. The proof, that the cilia are identical in morphological and functional res pect at the human ciliated epithelium and at T. pyriformis has been reached by electron optical comparative representation and bibliographical known s ubstances, influencing cilia (theophylline, bromhexine, ambroxol, terpin hy drate, mercaptoethanesulfonatsodium, amrinon, salbutamol, tetracosactid-hex aacetate, histamine, and phenol). With regard to the comparability and appl icability to the human respiratory ciliated epithelium we have been able to gain statements by means of the CMT. By constructing a special reaction vessel the influence of harmful gases at a thin layer of ciliate culture suspension (1 cm) for a standardised expos ure time (1 hour) has been made possible and with that a model for the comp arability with the conditions of the human respiratory ciliated epithelium has been created. A number of harmful gases, that are relevant in the air hygiene (CO, CO2, N -2, N2O, NO2, O-3, SO2) as well as cigarette smoke at active smokers (prima ry stream smoke) and the inhalation of the smoke of other people's cigarett es has been tested. It turned out, that especially NO2 (nitric oxide) shows a high ciliar toxic ity, while the controversially discussed ozone (O-3) has not resulted in de traction of cilia. CO, N2O and SO2 have been - to a great extent - harmless on cilia in the concentration range relevant in the air hygiene. Remarkable are the results, that cigarette smoke shows clear toxic effects on cilia both at active smoking, as well as the inhalation of the smoke of other people's cigarettes. With that another contribution to the discussion about the harmfulness of active smoking and the inhalation of the smoke of other people's cigarettes is made.