title: [Studies on the mechanism of action of clonidine after pretreatment with reserpine (author's transl)].
abstract: The effects of 3.7--30 micrograms 2-(2,6-dichlorophenolamino)-2-imidazoline hydrochloride (clonidine)/kg i.v. on the arterial blood pressure and the central nervous activities of the sympathetic and the phrenic nerves were studied in 33 anaesthetized, relaxed and artificially respirated cats. In part of the experiments the animals were pretreated with reserpine at a dosage of 2X0.3 mg/kg. In normal animals clonidine caused a fall in blood pressure, a reduction of nicotinic pressure effect and an inhibition of sympathetic activity. In pretreated animals the antinicotinic as well as the sympathetic inhibitory actions of clonidine were significantly increased at a dosage of 30 micrograms/kg. The single application of reserpine caused no changes of these two parameters. As a result clonidine probably caused a stimulation of central nervous postsynaptic alpha-adrenoceptors and after the pretreatment with reserpine in addition to this an inhibition of the release of epinephrine.
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D002490:Central Nervous System / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology*; D004347:Drug Interactions; D010275:Parasympathetic Nervous System / Q000187:drug effects; D012110:Reserpine / Q000494:pharmacology*; D013564:Sympathetic Nervous System / Q000187:drug effects
chemical_list: D012110:Reserpine; D003000:Clonidine
vernacular_title: Untersuchungen zum Wirkungsmechanismus von Clonidin nach Vorbehandlung mit Reserpin.