Evidence of melatonin involvement in pindolol-induced suppression of REM sleep.
The effects of pindolol, melatonin, and the melatonin receptor agonist agomelatine were studied in rats implanted for chronic sleep procedures. Administration of pindolol (1.0-4.0 mg/kg) during the light phase induced a significant reduction of rapid-eye-movement sleep (REMS) and an increase of waking (W). In the rats recorded after receiving 1.0-6.0 mg/kg melatonin no significant differences were found in sleep or W compared with controls. Agomelatine (1.0-6.0 mg/kg) induced a significant increase of light sleep during the first 3 h of the recording period. Pretreatment with melatonin partly prevented the pindolol-induced suppression of REMS. However, agomelatine was ineffective in this respect. Overall, these data suggest that the decreased production of melatonin could play a role in REMS suppression related to pindolol administration.
Department of Pharmacology and Therapeutics, Clinics Hospital, Montevideo, Uruguay. jmonti@mednet.org.uy
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D000081:Acetamides / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D008550:Melatonin / Q000378:metabolism* / Q000494:pharmacology; D010869:Pindolol / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000378:metabolism; D044094:Receptors, Melatonin; D012895:Sleep, REM / Q000187:drug effects* / Q000502:physiology*; D009281:Naphthalenes
D000081:Acetamides; D000319:Adrenergic beta-Antagonists; D008550:Melatonin; D010869:Pindolol; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D044094:Receptors, Melatonin; C084711:agomelatine; D009281:Naphthalenes