Systemic injection of a nitric oxide synthase inhibitor suppresses sleep responses to sleep deprivation in rats.
We hypothesized that nitric oxide (NO) may play a role in homeostatic sleep regulation. To test this hypothesis, we studied the sleep deprivation (SD)-induced homeostatic sleep responses after intraperitoneal administration of an NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME, a cumulative dose of 100 mg/kg). Amounts and intensity of sleep were increased in response to 8 h of SD in control rats (n = 8). Sleep amounts remained above baseline for 16 h after SD followed by a negative rebound. Rapid eye movement sleep (REMS) and non-REMS (NREMS) intensities were elevated for 16 and 4 h, respectively. L-NAME treatment (n = 8) suppressed the rebound increases in NREMS amount and intensity. REMS rebound was attenuated by L-NAME in the first dark period after SD; however, a second rebound appeared in the subsequent dark period. REMS intensity did not increase after SD in L-NAME-injected rats. The finding that the NO synthase inhibitor suppressed rebound increases in NREMS suggests that NO may play a role as a signaling molecule in homeostatic regulation of NREMS.
Ribeiro
A C
AC
Department of Biological Sciences, Fordham University, Bronx, New York 10458, USA.
Gilligan
J G
JG
Kapás
L
L
D000818:Animals; D004569:Electroencephalography; D004576:Electromyography; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005583:Fourier Analysis; D006706:Homeostasis / Q000502:physiology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000187:drug effects / Q000502:physiology; D012892:Sleep Deprivation / Q000201:enzymology*; D012895:Sleep, REM / Q000187:drug effects / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology
D004791:Enzyme Inhibitors; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester