ENHANCEMENT AND NEUTRALIZATION OF PYROGENICITY OF INFLUENZA VIRUSES BY VARIOUS BIOLOGICALLY ACTIVE SUBSTANCES

Experiments were performed to modify the influenza virus-induced pyrogenicity by varying the milieu in which the virus is suspended. The results show that lysozyme and aristolochia acid in afebrile dosages enhance the virus pyrogenicity in rabbit pyrogen test. It is supposed that this stimulating effect is due to a promoting virus phagocytosis. Mixtures of lysozyme and aristolochia acid do not lead to a higher enhancement of virus pyrogenicity but, on the other hand, often induce an effect somewhat less than that of lysozyme or aristolochia acid alone. Detergents such as sodium deoxycholate and vitamin A on the contrary suppress the pyrogenic activity of influenza virus particles probably by delaying virus phagocytosis. The same result is to be observed with sucrose and polymyxin B in certain dosages. It must be emphasized that the presence of the substances just mentioned can possibly be a source of error in performing the usual rabbit pyrogen test. In addition to our findings further recommendations for a useful application of lysozyme and aristolochia acid for instance in practical treatment of viral diseases are given since these substances may shorten the viraemic phase. © 1969 Springer-Verlag.