Pyrogenicity of yeast mannans in rabbits.

A few yeast mannans free from protein and phosphorus showed pyrogenic activity in rabbits although the extent of this activity was considerably lower than that of the bacterial lipopolysaccharides (LPS). The pyrogenic activity was not abolished by treatment with sodium deoxycholate. This result showed that the mannans themselves participated in the pyrogenicity, excluding any possibility of LPS contamination in the mannans. Concerning the relationship between chemical structure and pyrogenicity of these mannans, it was demonstrated that a mannan possessing a highly branched structure exhibited stronger pyrogenicity than that of a less branched one.