title: Dopamine receptor profile of co-dergocrine (Hydergine) and its components.
abstract: Co-dergocrine (Hydergine), an ergot preparation composed of four dihydrogenated peptide ergot alkaloids (dihydroergocornine, dihydroergocristine, dihydro-alpha-ergokryptine, dihydro-beta-ergokryptine, 3:3:2:1), has been reported to exert in vivo effects suggesting an interaction with dopaminergic systems. The present investigation provides evidence that, in the striatum of the rat, co-dergocrine and its components interact directly with D1- and D2-subtypes of dopamine receptors. In homogenates of rat striatum, co-dergocrine and three of its components (dihydroergocornine, dihydro-alpha-ergokryptine, dihydro-beta-ergokryptine) stimulate cyclic AMP formation (D1-receptor response) having similar EC50 values but different efficacies. The same compounds inhibit electrically evoked tritium overflow from rat striatal slices preincubated with [3H]choline (D2-receptor response) at about 50 times lower concentrations. Here again the compounds exhibit differential maximal effects. One component, dihydroergocristine, antagonises both receptor types. The effect of co-dergocrine in functional responses mediated by both D1- and D2-receptors seems to reflect the summation of the contribution of its components.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002794:Choline / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D004088:Dihydroergotoxine / Q000494:pharmacology*; D004558:Electric Stimulation; D004876:Ergot Alkaloids / Q000494:pharmacology; D008297:Male; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D013134:Spiperone / Q000494:pharmacology
chemical_list: D004876:Ergot Alkaloids; D011954:Receptors, Dopamine; D004088:Dihydroergotoxine; D013134:Spiperone; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D001058:Apomorphine; D002794:Choline