Acute effects of vitamin A on the kinetics of endotoxin in conscious rabbits.
BACKGROUND
Vitamin A reduces the pathophysiological effects of endotoxin in animals, but the mechanism and the lowest effective dose are not clear.


METHODS
An intravenous bolus of endotoxin 20 microg. kg(-1) was given to 30 rabbits. In 10 of them, 1000 IE. kg(-1) retinyl palmitate was injected intravenously 1 h before the endotoxin and in another 10 rabbits 1 h after the endotoxin. A one-compartment open model was fitted to the time-concentration profile of endotoxin in plasma.


RESULTS
The half-life of endotoxin was half as long when vitamin A was given for prophylaxis (median 35 min) and for treatment (33 min) than in the controls (67 min; p < 0.004). The plasma concentrations of immunoglobulin G and M endotoxin-core antibodies, the leucocyte count and the acid-base balance did not differ between the groups during the experiment, but the pyrogenic reaction was more pronounced in the controls.


CONCLUSIONS
A fairly low dose of vitamin A reduced the half-life of endotoxin.
Iversen
M H
MH
Department of Anaesthesia, Stockholm Söder Hospital, S-11 883 Stockholm, Sweden.
Hahn
R G
RG
D000704:Analysis of Variance; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016470:Bacteremia / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D004195:Disease Models, Animal; D004224:Diterpenes; D004353:Drug Evaluation, Preclinical; D004731:Endotoxins / Q000008:administration & dosage / Q000276:immunology / Q000493:pharmacokinetics*; D004926:Escherichia coli / Q000276:immunology; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007275:Injections, Intravenous; D007958:Leukocyte Count; D008657:Metabolic Clearance Rate; D017711:Nonlinear Dynamics; D011817:Rabbits; D011897:Random Allocation; D012044:Regression Analysis; D000084562:Retinyl Esters; D013997:Time Factors; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000907:Antibodies, Bacterial; D004224:Diterpenes; D004731:Endotoxins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate