Dose-response effect of in vivo administration of endotoxin on polymorphonuclear leukocytes oxidative burst.
In vitro, endotoxin primes polymorphonuclear leukocytes (PMNs) to respond with a greater oxidative burst. The purpose of the present study was to investigate the in vivo effect of a wide range of single endotoxin bolus doses using a rat model. PMNs were subsequently challenged in vitro with phorbol ester to produce reactive oxygen intermediates (ROI). Flow cytometric determination of ROI production by large doses induced a decrease in ROI production by the few PMNs that remained in the circulation. By 6 h after injection, ROI production had returned to basal levels after a high dose, and was still increasing after a low dose. Neutropenia occurred immediately after endotoxin injection. After 6 h, PMN counts returned to almost normal levels with a high dose, but rebound neutrophilia occurred with a small dose. In contrast to in vitro studies, in vivo injection showed a response pattern that varied widely with dose and time of observation.
Kajdacsy-Balla
A
A
Department of Pathology, University of Oklahoma Health Science Center, Oklahoma City 73190, USA.
Doi
E M
EM
Lerner
M R
MR
Bales
W D
WD
Archer
L T
LT
Wunder
P R
PR
Wilson
M F
MF
Brackett
D J
DJ
D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000008:administration & dosage*; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects*
D004731:Endotoxins; D017382:Reactive Oxygen Species