This study was undertaken to examine some of the properties of staphylococcal
toxic shock syndrome toxin 1 (TSST-1) with regard to the clearance of
endotoxin from blood. The concentration of
endotoxin in blood was measured by using a chromogenic limulus test and modified
perchloric acid method. When
TSST-1, which produces
fever in rabbits, was injected (100 ng/ml or 100 micrograms/ml per kg) intravenously (i.v.) into the animals, no measurable level of
endotoxin was detected in the blood. In control animals, which were given 5 micrograms of
endotoxin per ml per kg i.v.,
endotoxin could be detected in the blood at rapidly declining levels. These results suggested that
TSST-1 might not lead bacterial
endotoxin from other body sites into the blood. When the animals were given
TSST-1 (1 to 100 ng/ml per kg) i.v. and then
endotoxin (5 micrograms/ml per kg) i.v. 4 h later,
endotoxin was detected in the blood at a high level, depending on the dose of
TSST-1 injected. These results showed that
TSST-1 inhibited the clearance of
endotoxin in the blood; this clearance is thought to be mainly done by the reticuloendothelial system. In the animals given
TSST-1 (100 ng/ml per kg) and
endotoxin (5 micrograms/ml per kg) simultaneously, the
endotoxin level in the blood was found to be higher than that in control animals given
endotoxin only but lower than that in the animals given
TSST-1 and then
endotoxin at the same doses.