Abstract
A significant proportion of castrated male hamsters inoculated with MEF1 virus intraperitoneally developed paralytic poliomyelitis, whereas non-castrated controls were completely refractory to the virus by this route. Enhancement of susceptibility observed immediately after castration was reversed during the compensatory stage 2 weeks later. The effect of castration upon susceptibility to experimental poliomyelitis was synergistic with cortisone during the initial stage, but antagonistic during the compensatory stage.