The effects of DSIP on pain threshold during light and dark periods in rats are not naloxone-sensitive.
The effects of Delta-Sleep-Induced Peptide (DSIP) were examined in rats kept at 12:12 light:dark schedule. The peak of the circadian pain threshold of saline-treated rats occurred at 10:00. Rats treated with 0.1 mg/kg, i.p. DSIP exhibited a significantly higher pain threshold level (as measured by hot plate) both in the light and dark periods. Prior to the treatment the peak was at 10:00. With treatment the peak shifted to 18:00. A dose of 1.0 mg/kg DSIP increased the pain threshold level only during the dark period. The analgesia induced by DSIP is insensitive to naloxone pretreatment.
Yehuda
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S
Department of Psychology, Bar-Ilan University, Ramat-Gan, Israel.
Carasso
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RL
D000818:Animals; D002940:Circadian Rhythm; D003701:Delta Sleep-Inducing Peptide / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012684:Sensory Thresholds / Q000187:drug effects
D009270:Naloxone; D003701:Delta Sleep-Inducing Peptide