Paxillin

To control severe tremors caused by tremorgenic mycotoxins, methocarbamol should be administered. Generalized seizures may be treated with diazepam followed by methocarbamol or a barbiturate such as pentobarbital sodium. Gastric lavage should be performed and activated charcoal administered to limit further absorption of toxins. (A744)

Tremorgenic mycotoxins exert their toxic effects by interfering with neurotransmitter release, possibly by causing degeneration of nerve terminals. They are thought to inhibit gamma-aminobutyric acid (GABA) receptors, both pre- and postsynaptic, as well as inhibit transmitter breakdown at the GABA-T receptors. This would initially increase neurotransmitter levels, potentiating the GABA-induced chloride current, then lead to decreased levels of neurotransmitter in the synapse. In addition, paxilline inhibits presynaptic high-conductance Ca+2 activated maxi-K+ channels in the smooth muscle. Paxilline is also genotoxic and causes DNA damage. (A2976, A2993, A3026)

Tremorgenic mycotoxins affect central nervous system activity, inducing neurologic symptoms including mental confusion, paralysis, tremors, seizures, and death. They cause a neurological disease of cattle known as "staggers syndrome", which is characterized by muscle tremors, hyperexcitability, convulsions and ataxia. (A2976)