Dual effects of melatonin on barbiturate-induced narcosis in rats
Authors | |
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Year of publication | 2001 |
Type | Article in Periodical |
Magazine / Source | Neuroscience Letters |
Citation | |
Doi | http://dx.doi.org/10.1016/S0304-3940(01)01578-6 |
Field | Neurology, neurosurgery, neurosciences |
Keywords | melatonin; sodium thiopenthal; narcosis; ketamine; diazepam; low doses |
Description | Melatonin affects the circadian sleep/wake cycle, but it is not clear whether it may influence drug-induced narcosis. Sodium thiopenthal was administered intraperitoneally into male rats pre-treated with melatonin (0.05, 0.5, 5 and 50 mg/kg). Melatonin pre-treatment affected in a dual manner barbiturate narcosis, however, no dose-effect correlation was found. In particular, low doses reduced the latency to and prolonged the duration of barbiturate narcosis. In contrast, the highest dose of melatonin (50 mg/kg) caused a paradoxical increase in the latency and produced a sustained reduction of the duration of narcosis, and a reduction in mortality rate. Melatonin 0.5 and 5 mg/kg influenced the duration but not the latency of ketamine- or diazepam-induced narcosis. Thus, the dual action of melatonin on pharmacological narcosis seems to be specific for the barbiturate mechanism of action. (C) 2001 Published by Elsevier Science ireland Ltd. |