Acromelic acid, a novel excitatory amino acid from a poisonous mushroom: effects on the crayfish neuromuscular junction.

A novel amino acid, acromelic acid, which is one of kainoids isolated from a poisonous mushroom, markedly depolarizes the crayfish opener muscle fiber in a dose-dependent manner, its potency being much greater than that of kainoids such as kainic or domoic acid. Moreover, acrolemic acid markedly potentiates the glutamate response, in spite of the fact that it reduces the quisqualate response in a dose-dependent manner. The amplitude of excitatory junctional potentials was slightly reduced by acromelic acid.