1957 年 7 巻 6 号 p. 381-387
Several kinds of ammonium salt inhibited the propagation of influenza virus in vitro in a very low concentration (10-3M or less). Out of several kinds of ammonium salt, NH4Cl was selected and its effect upon influenza virus multiplication in vitro was observed. Ammonium chloride did neither prevent the adsorption of the virus to the host cells nor inactivate the virus directly. The earlier the addition of ammonium chloride after virus infection, the stronger inhibitory effect was observed. Even when ammonium chlorid was removed from the cultivated tissue by washing, the virus propagation was very small even after 24 hour of virus infection, but the multiplication occurred in later stages and after 48 hour virus titer was almost the same as the control without ammonium chloride. Furthermore. on the previously with ammonium chloride treated host tissue virus multiplication was much smaller 24 hour after infection than that of control, but in later stage (48th hour after infection) virus propagated on the both treated-and nontreated host cell to the almost same titer. Therefore, ammonium chloride may inhibit probably the virus multiplication by damaging normal host cells on which the virus would be propagated. Such a damage of the normal cells was reversible, although its convalescence was delayed for a long time.