[Demonstration of a bacterial structure in two human mediators: a sleep facilitating factor and a monokine].

A monoclonal anti-MDP antibody was found to bind to "Slow Wave Sleep" factor. This result confirms that this factor is a muramyl peptide and furthermore shows that it contains a structure characteristic of the synthetic adjuvant and of the bacterial cell wall, i.e. an acetylated muramic acid bound to L-alanine. This antibody was also shown to specifically inhibit a biological activity of a purified human monokine which induces fever. Because of these results and other recent observations we propose that a bacterial structure is present in certain mammalian mediators.