Subcellular localization of leucocytic fever-suppressing factors

Abstract

Subcellular fractions of neutrophilic leucocytes collected from rabbit peritoneal exudates were separated by differential centrifugation. The effects of each fractions on pyrogenicity of bacterial lipopoly saccharide were examined. The fever-suppressing activity was found in two fractions, 7, 000g 10m pellet (neutrophilic B granules fraction) and 14, 000g 10m pellet (neutrophilic A glanules fraction). The fever-suppressing factor in 7, 000g pellet was inactivated by the 60°C 30m heat treatment or freezing-and-thawing. The fever-suppressing factor in 14, 000g pellet was inactivated by the 60°C 30m heat treatment, but they were activated with freezing-and-thawing or sonication. Then A granules were sonicated and centrifuged 78, 000g 120m. The fever-suppressing activity was found in 78, 000g pellet of A glanules. Supernatant was fractionated with ammonium sulfate. The activity was appeared in 80% saturated supernatant. Paper-electrophoretical data showed that active substance might be cationic or basic polypeptide. The physiological significancy of this fever-suppressing factors are discussed.