Effects of L-arginine and SIN-1 on sleep and waking in the rat during both phases of the light-dark cycle.
The effects L-arginine (0.15-0.60 micromol), a nitric oxide precursor, and SIN-1 (3-morpholino-sydnonimine; linsidomine) (0.05-0.2 micromol), a nitric oxide donor, on spontaneous sleep were studied in adult rats implanted for chronic sleep recordings. L-arginine or SIN-1 given intracerebroventricularly during the light phase of the light-dark cycle induced no significant changes in sleep variables. On the other hand, administration of L-arginine or SIN-1 during the dark phase significantly increased slow wave sleep and reduced waking during the first 4 h of the recording period. The time spent in rapid-eye-movement sleep (REMS) was not significantly modified. The increase of slow wave sleep and/or reduction of waking was already evident during the first 2 h of recording. On the other hand, values of these variables were not different from control values during post-injection hours 5 and 6. Our findings confirm the role of nitric oxide, generated from L-arginine or released from SIN-1, in the regulation of sleep variables in the rat.
Department of Pharmacology and Therapeutics, Clinics Hospital, 2833/602 Zudañez Street, Montevideo 11300, Uruguay. jmonti@mednet.org.uy
Jaime M
JM
Monti
Héctor
H
Jantos
D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002490:Central Nervous System / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D004576:Electromyography; D008297:Male; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D017440:Photoperiod; D051381:Rats; D012890:Sleep / Q000187:drug effects*; D013997:Time Factors
D009569:Nitric Oxide; C002385:linsidomine; D001120:Arginine; D008981:Molsidomine