The growth curve of the Lansing strain of poliomyelitis virus in mice: the effect of sodium monofluoroacetate and methionine sulfoximine on the early phase of growth of the virus.

The early phase of growth of the Lansing strain of poliomyelitis virus in the mouse brain and cord was suppressed, or delayed, by the intraperitoneal administration of sodium monofluoroacetate in doses of 6 mg./kg. but not of 3 mg./kg. 1 hour before the intracerebral inoculation of virus. There was also a delay in the time at which the first signs of illness appeared in the treated mice. Similar effects, but to a lesser degree, were observed after the administration of DL-methionine sulfoximine in doses of 150 mg./kg. and 75 mg./kg. Sodium fluoroacetate in very high concentration had no direct effect in vitro on the infectivity of poliomyelitis virus. It was found that in each instance in which the growth of virus was delayed, the time at which the first obvious signs of illness appeared was also delayed in a proportionate manner. The significance of these findings is discussed, as well as the use of the growth curve of poliomyelitis virus in mice in studying the relation of cellular metabolism to viral synthesis and the search for effective chemical agents.