On some central effects of elymoclavine.

: The pharmacological investigation of the ergot alkaloid of the group of clavines elymoclavine isolated from Claviceps sp. cp. II showed the following: LD50 for mice for 24 hours was 350 (228 divided by 535) mg/kg and for rats--145 (81 divided by 258) mg/kg; elymoclavine induced a dose-dependent stereotypy in rats and mice which was antagonized by haloperidol and pimozide; it prevented the development of haloperidol catalepsy in rats and produced rotations contralateral to the striatal lesions with 6-OHDA which were antagonized by pimozide and partly by cyproheptadine. Elymoclavine increased the exploratory activity of rats in open field as this effect was antagonized by haloperidol and was essentially influenced by many substances acting on different transmitter systems (NA, DA, GABA). Elymoclavine inhibited the picroroxin and electroshock convulsive seizures but potentiated the pentylenetetrazol ones in mice as these effects were differently influenced by pimozide, haloperidol, 5-HT, atropine and phentolamine. The observed effects of elymoclavine are mainly due to its DAergic agonistic action. It seems, however, that influences on other transmitter receptors also underlie the mechanism of action of this ergot alkaloid.