[A study of the mechanism of L-NNA on sleep inhibition].
In the present study, the sleep-waking cycle and the immunoreactivity of 5-HT-containing neurons in rats receiving intraperitoneal injections of N-Nitro-L-arginine (L-NNA, 50 mg/kg) and L-arginine (L-arg, 110 mg/kg) were observed respectively. The results showed that injection of L-NNA suppressed both slow wave sleep (SWS) and rapid eye movement sleep (REMS) and increased mean arterial pressure (MAP). L-arg markedly attenuated MAP, whereas SWS and REMS were unchanged. The effects of L-NNA on sleep and MAP were reversed by preinjection of L-arg. In comparison with control group, the positive cells in dorsal raphe nucleus (DR) and raphe magus nucleus (MnR) increased 2 h after injection of L-NNA. The effect was attenuated by preadministration of L-arg. All these results suggest that L-arg: NO pathway is involved in the regulation of sleep-waking cycle and the increment of the positive immunoreactivity of the 5-HT-containing neurons in the DR may be related to the sleep-suppressive effects induced by L-NNA.
Zhang
Q
Q
Department of Physiology, Henan Medical University, Zhengzhou.
Wang
S C
SC
Qiao
P
P
Hu
Q Y
QY
Chen
L C
LC
Wang
Y R
YR
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D005260:Female; D007274:Injections, Intraperitoneal; D008297:Male; D009474:Neurons / Q000502:physiology; D019335:Nitroarginine / Q000494:pharmacology*; D011903:Raphe Nuclei / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000502:physiology; D012890:Sleep / Q000187:drug effects*
D019335:Nitroarginine; D012701:Serotonin; D001120:Arginine