Toxic and lethal effects of T-2 toxin upon intracerebral administration to rats

T-2 toxin was given to rats in three ways: Subcutaneous or intracerebral injection of a solution in dimethyl sulfoxide (DMSO) and by implantation of toxin, adsorbed on talc, into various regions of diencephalon and brain stem. The latter method proved to be most effective. Within a few hours after administration of 10-20 micrograms toxin, the animals became restless, ataxic and dyspneic. These early symptoms were followed by depression and immobility. Prior to death, tachypnea and/or convulsions developed. The rats succumbed to implantation of toxin within 1 - 7 days; no fatalities occurred at later dates. Histologically, the toxin pellets caused necrosis a few days after implantation; at a later stage, the necrotic areas were surrounded by inflammatory infiltrates around small blood vessels. These morphological changes were limited to the application site and were insufficient to explain the lethal effect of intracerebral administration. After intracerebral injections of toxin solutions, the animals died within 24 h. No marked histological changes could be seen after such rapid fatalities.