Pharmacological studies with two new ergoline derivatives, the potential antipsychotics LEK-8829 and LEK-8841.

The pharmacological properties of 9,10-didehydro-N-methyl-N-(2-propynyl)-6-methyl-8 beta-aminomethylergoline (LEK-8829) and 9,10-didehydro-N-methyl-N-(2-propynyl)-2-bromo-6-methylergoline -8-beta-carboxamide (LEK-8841), new ergoline derivatives, were compared with those of haloperidol and clozapine by in vitro radioligand displacement assays, various behavioral tests and blood pressure measurements. Both ergolines displayed low affinity for rat striatal 3H-SCH23390 (7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzaze pin e)- labeled dopamine (D)1 binding sites and high affinity for striatal 3H-spiperone-labeled D2 and cortical 3H-ketanserin-labeled serotonin-2 (5-HT2) sites. The ratio of pKi values 5-HT2/D2 was 1.