Little sleep-promoting effect of three sleep substances diurnally infused in unrestrained rats.
Delta-sleep-inducing peptide (2.5 nmol), prostaglandin D2 (0.36 nmol) and uridine (10 pmol) were intraventricularly infused for 10 h at daytime in otherwise saline-infused freely moving male rats. In contrast to a nocturnal infusion which may result in marked sleep-promoting effects, such a diurnal infusion brought about almost no change in sleep parameters. It is postulated that the requirement of sleep in rats might be fully achieved at the environmental light period to cancel the effect of the exogenously administered sleep substances. It is proposed that an endogenous sleep substance should be characterized by a property not to cause excessive sleep at the time when sleep is physiologically saturated.
D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D003701:Delta Sleep-Inducing Peptide; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D009842:Oligopeptides / Q000494:pharmacology; D015230:Prostaglandin D2; D011457:Prostaglandins D / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012890:Sleep / Q000187:drug effects*; D014529:Uridine / Q000494:pharmacology
D006993:Hypnotics and Sedatives; D009842:Oligopeptides; D011457:Prostaglandins D; D003701:Delta Sleep-Inducing Peptide; D015230:Prostaglandin D2; D014529:Uridine