Chronic treatments with 5-HT1A agonists attenuate posthypoxic myoclonus in rats.
Following 10 min cardiac arrest and resuscitation, male Sprague-Dawley rats developed posthypoxic myoclonus. This phenomenon peaked at 14 days and disappeared by 60 days after cardiac arrest. From previous results, the 5-hydroxytryptamine (5-HT) system was implicated in the pathogenesis of the disease. In the present study, we investigated the involvement of 5-HT1A receptors in posthypoxic myoclonus in rats. Single injections of 5-HT1A agonists, buspirone (5 and 10 mg/kg body wt.) or 8-OH-DPAT (1, 2, and 4 mg/kg), had no effect on either the intensity or time course of the disease. In contrast, multiple injections (twice a day for 7 or more days) of buspirone (10 mg/kg) or 8-OH-DPAT (4 mg/kg) significantly attenuated the myoclonus scores of animals (p < 0.05). The results indicate that chronic stimulation of 5-HT1A receptors in the brain may accelerate endogenous compensatory mechanisms and shorten the time course of the disease.
Parkinson and Movement Disorders Laboratory, Department of Neurology, University of California Irvine 92717, USA.
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D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D006323:Heart Arrest / Q000139:chemically induced / Q000503:physiopathology; D002534:Hypoxia, Brain / Q000150:complications*; D008297:Male; D008954:Models, Biological; D009207:Myoclonus / Q000188:drug therapy* / Q000209:etiology; D011189:Potassium Chloride; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation; D012702:Serotonin Antagonists / Q000627:therapeutic use; D017366:Serotonin Receptor Agonists / Q000627:therapeutic use*
D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D011189:Potassium Chloride