The 5-HT1A antagonist (-)-alprenolol fails to modify sleep or zimeldine-induced sleep-waking effects in rats.
Sleep and waking in rats were studied for 8 h following administration of a selective 5-hydroxytryptamine (5-HT) reuptake inhibitor (zimeldine), a putative 5-HT1A antagonist (L(-)-alprenolol hydrogene tartrate monohydrate [(-)-alprenolol]) and a combination of (-)-alprenolol and zimeldine. Consistent with earlier findings, zimeldine gave a biphasic effect on sleep and waking. Waking was increased during the first 3 h, followed by a small decrease. Deep slow-wave sleep (SWS-2) showed the opposite trend. An initial decrease in SWS-2 was followed by an increase after around 3 h. Rapid eye movement sleep was markedly suppressed and latencies to sleep increased after zimeldine. (-)-Alprenolol had no effects on the different sleep and waking stages or latencies to sleep. The 5-HT1A antagonist also failed to modify the effects of zimeldine administration. The behavioral syndrome induced by a selective 5-HT1A agonist [8-hydroxy-2-(di-n-propyl-amino)-tetralin (8-OH-DPAT)] was clearly antagonized by administration of (-)-alprenolol, indicating that (-)-alprenolol was an efficient 5-HT1A blocker. The data indicate that the sleep-waking effects of zimeldine cannot easily be explained by stimulation of 5-HT1A receptors.
Bjorvatn
B
B
Department of Physiology, University of Bergen, Norway.
Neckelmann
D
D
Ursin
R
R
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000526:Alprenolol / Q000494:pharmacology*; D000818:Animals; D004569:Electroencephalography / Q000187:drug effects; D004576:Electromyography / Q000187:drug effects; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012702:Serotonin Antagonists / Q000494:pharmacology*; D012890:Sleep / Q000187:drug effects*; D012894:Sleep Stages / Q000187:drug effects; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D014851:Wakefulness / Q000187:drug effects*; D015031:Zimeldine / Q000494:pharmacology*
D012702:Serotonin Antagonists; D013764:Tetrahydronaphthalenes; D015031:Zimeldine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000526:Alprenolol