Effects of cyclopiazonic acid on the contractility of organs with smooth muscles, and on frog ventricles.

The mycotoxins cyclopiazonic acid (CPA) and ergotamine, and the neurotransmitter serotonin all have the beta-aminoethylindole moiety in common. These compounds enhanced the peristaltic movements of the jejunum, ileum and estrous uterus and produced broncho-constriction in vitro. Atropine and cyproheptadine were able to counter the CPA-induced peristaltic movements of the ileum and jejunum. L-epinephrine was able to stop the contractions induced by CPA on both estrous and pregnant rat uteri. Unlike chlorpromazine, CPA did not block the inotropic effects of dopamine, epinephrine and serotonin in vas deferens. This indicated that the previously reported toxic effects of CPA (hypothermia, catalepsy, hypokinesia, tremor) which resembled the effects of anti-psychotic drugs (chlorpromazine, reserpine) probably were not due to the blocking of the neurotransmitter-receptors. In contrast to ergotamine, which decreased the inotropic effects of serotonin on the uterus, CPA had no anti-serotonin effects. The uterotonic effect of CPA (similar to that of ergotamine) suggested that CPA also might have an adverse effect on the reproductive function of humans and animals consuming CPA-contaminated foods.