Ergot alkaloids and central monoaminergic receptors

The interactions of ergolines and of ergopeptines with dopamine (DA), alpha 1 and alpha 2 central adrenoreceptors were studied. Ergolines and ergopeptines exert agonist activities at central DA receptors and exhibit antiparkinsonian activities in monkeys with unilateral ventromedial tegmental lesions of the brain stem. Both ergolines and ergopeptines are used in treatment of Parkinson's disease and their therapeutic efficacy, as well as their propensity to develop undesirable side effects is under investigation. The interactions of ergolines and of ergopeptines differ with DA receptor subtypes and states. The former are regulated by guanine nucleotides, but not the latter. Hydergine is used in treatment of disorders associated with senile dementia, and its interaction with DA, alpha 1 and alpha 2 adrenoreceptors may affect the monoaminergic imbalance in the aging brain.