Effect of tandospirone on sleep latency in rats placed on a grid suspended over water.
The present study was performed to examine the effect of tandospirone on sleep latency in a new insomnia animal model by placing rats on a grid suspended over water. For investigating the mechanism of tandospirone, the effect of tandospirone on sleep latency was also studied using rats that were depleted with neuronal serotonin (5-HT) after p-chlorophenylalanine administration. Tandospirone caused a shortening of sleep latency dose-dependently, and a significant effect was observed at 20 mg/kg, p.o. or more. A shortening of sleep latency was observed by administration of p-chlorophenylalanine (300 mg/kg, i.p.) for 2 days. On the other hand, tandospirone exerted no potentiating effect on the shortening of sleep latency induced by p-chlorophenylalanine. From these findings, a shortening of sleep latency induced by tandospirone may occur through the pre-synaptic 5-HT(1A) receptors in rats.
Utsu
Yoshiaki
Y
Department of Medicinal Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka 1-1-1, Okayama 700-8530, Japan.
Shinomiya
Kazuaki
K
Tokunaga
Shin
S
Ohmori
Asae
A
Kamei
Chiaki
C
D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D004576:Electromyography; D010134:Fenclonine / Q000008:administration & dosage / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D054833:Isoindoles / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D011743:Pyrimidines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D012890:Sleep / Q000187:drug effects* / Q000502:physiology; D012892:Sleep Deprivation / Q000209:etiology / Q000503:physiopathology*; D012893:Sleep Wake Disorders / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects* / Q000502:physiology; D014867:Water / Q000009:adverse effects