The composition of sleep-promoting factor isolated from human urine

Area of Science:

• Neuroscience
• Biochemistry
• Sleep Science

Background:

• A naturally occurring sleep-promoting substance, termed Factor S, has been previously identified.
• The precise chemical nature and origin of Factor S have remained largely undetermined.

Purpose of the Study:

• To extract and purify the sleep-promoting substance Factor S from human urine.
• To characterize the chemical composition of purified Factor S.
• To evaluate the sleep-inducing effects of Factor S in a mammalian model.

Main Methods:

• Large volumes of human urine were processed to isolate and purify Factor S.
• Amino acid and amino sugar analyses were performed on the purified glycopeptide.
• Purified Factor S was infused into the lateral ventricle of rabbit brains.

Main Results:

• Factor S was successfully extracted and purified as a small glycopeptide.
• Analysis revealed a composition of glutamic acid, alanine, diaminopimelic acid, and muramic acid.
• Infusion of approximately 5 pmol/kg of Factor S increased slow wave sleep by 50% in rabbits.
• The induced sleep was characterized as normal deep sleep.

Conclusions:

• Urinary Factor S is a glycopeptide with a unique composition, suggesting a non-adventitious origin.
• Factor S possesses potent sleep-promoting properties, significantly enhancing slow wave sleep.
• Further research is warranted to elucidate the precise biological role and origin of Factor S.