Clonidine suppression of bradycardia induced by gigantocellular reticular nucleus in the cat.
In chloralose-urethane-anesthetized cats, intravertebral injection of clonidine (0.5--4.0 micrograms/kg) elicited a drastic suppression of the bradycardia induced by stimulating the gigantocellular reticular nucleus (GRN). The degree of blockage of GRN-induced cardioinhibtion was related to the time course of the inherent cardiovascular effects of clonidine. It was also dependent upon the dose of the imidazoline compound and the intensity/train pulse frequency of reticular stimulation. It was suggested that the two mechanisms may interact with one another in the brainstem and possible modes of interaction were discussed.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D003000:Clonidine / Q000494:pharmacology*; D004558:Electric Stimulation; D006339:Heart Rate / Q000187:drug effects*; D008526:Medulla Oblongata / Q000502:physiology*
D003000:Clonidine