J. Muhling et al., Effects of etomidate on free intracellular amino acid concentrations in polymorphonuclear leucocytes in vitro, ACT ANAE SC, 44(4), 2000, pp. 429-435
Citations number
36
Categorie Soggetti
Aneshtesia & Intensive Care","Medical Research Diagnosis & Treatment
Background: Previous studies have shown the inhibitory effects of etomidate
on polymorphonuclear leucocyte (PMN) function. No reports exist, however,
regarding free intracellular amino acid metabolism, although physiological
cell metabolism and basic cell functions rely upon a balanced intracellular
amino acid content and the cell membrane-mediated separation of cellular a
mino acids from the extracellular plasma amino acid pool. Thus, in the curr
ent study, we evaluated the effects of etomidate on free intracellular amin
o acid metabolism in PMN.
Methods: With ethics committee approval, blood was withdrawn from 35 health
y volunteers and incubated (1 h) either with 0 mu g/ml, 0.0156 mu g/ml, 0.0
625 mu g/ml or 0.5 mu g/ml of etomidate as well as with its additives (prop
ylene glycol and Lipofundin MCT(R) 10%). The PMN were separated using stand
ardized Percoll(R)-gradient and centrifugation procedure before deep-freezi
ng and lyophilization techniques were employed. All PMN samples were dissol
ved in methanol/H2O, and the concentrations of free intracellular amino aci
ds were monitored using both novel advanced PMN-separation and high-perform
ance liquid chromatography techniques.
Results: Etomidate influenced important free amino acid profiles in PMN in
a dose-dependent manner, indicating complex changes of cellular amino acid
turnover. Neither propylene glycol nor Lipofundin MCT(R) 10% changed free a
mino acid concentrations in PMN.
Conclusions: For the first time, the effects of etomidate on free intracell
ular amino acid metabolism in PMN have been investigated. Our results draw
attention to the biochemical pathways which may be involved in etomidate-in
duced alterations in PMN function and cellular immunocompetence.
(C) Acta Anaesthesiologica Scandinavica 44 (2000).