Sleep-promoting substances

The most recent attempt to purify sleep factor(s) from sleep-deprived animals started in the 1970s in Japan. A sleep-promoting substance (conveniently named SPS ) was purified from the brain stem of sleep-deprived rats (Nagasaki et al. 1974). The extract contained at least four somnogenic fractions. Subsequent analysis identified SPS-A as uridine (Iriki et al. 1983) and SPS-B as oxidized glutathione (Komoda et al. 1990). 

Borbely, A. A. Tobler, I. (1989). Endogenous sleep-promoting substances and sleep regulation. Physiol Rev. 69, 605-70. 

The concept of humoral, rather than neural, regulation of sleep dates back almost 100 years when Kuniomi Ishimori and Henri Pieron demonstrated the presence of endogenous sleep-promoting substance(s) that had accumulated in the CSF of sleep-deprived dogs. PGD2 is the most plausible candidate of their endogenous sleep-promoting substance, based on the data obtained in our own and other laboratories over the past 20 years, as summarized in this chapter. 

Another controversial but exciting area of research is the potential role of serotonin in sleep. 5-Hydroxytryptamine may trigger slow-wave sleep (non-REM sleep), whereas the muscarinic AChR and NE are involved in REM sleep (rapid-eye-movement sleep, paradoxical sleep, dream sleep). In addition to the aminergic regulation of sleep, recent research has identified several other presumed sleep factors delta-sleep-inducing peptide, sleep-promoting substance, interleukin-1, and muramyl peptides. 

HI. The Role of Sleep-promoting Substances in Sleep Regulation. 525... 

Komoda Y, Ishikawa M, Nagasaki, H et al. Uridine, a sleep-promoting substance from brainstem of sleep- deprived rats. Biomed Res 1983 4 223-227. 

Honda, K., Komoda, Y., Nishida, S., et al. (1984) Uridine as an active component of sleep-promoting substance its effects on nocturnal sleep in rats. Neurosci. Res., 1, 243-252. 

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