Binding of propofol to human serum albumin.
The binding properties of the short-acting hypnotic agent propofol (CAS 2078-54-8) to human serum albumin were studied in vitro. Using centrifugation through ultrafiltration membranes the ratio of free and bound propofol as a function of the human serum albumin concentration was determined. In addition, a biomathematical approach was tested that allowed the determination of the number of binding sites from the measured binding profile. At a total propofol concentration of 8.81 +/- 0.25 microg/mL the concentration of the free fraction of propofol ranged from 338 +/- 11 ng/mL (mean +/- SE) at an albumin concentration of 0.5% to 15 +/- 2 ng/ mL at an albumin concentration of 8.0%. The corresponding percentage of propofol binding ranged from 96.07 +/- 0.14% to 99.83 +/- 0.02%. From this binding profile the binding site was estimated to be n(0) = 2. The measured influence of the albumin concentration on propofol binding might be of relevance in states of hypo- or hyperalbuminaemia which could result in an altered demand of propofol.
Schywalsky
Michael
M
Klinik für Anaesthesiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany. Michael.Schywalsky@kfa.imed.uni-erlangen.de
Ihmsen
Harald
H
Knoll
Rainer
R
Schwilden
Helmut
H
D000465:Algorithms; D018686:Anesthetics, Intravenous / Q000097:blood*; D001665:Binding Sites / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D015742:Propofol / Q000097:blood*; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D014462:Ultrafiltration
D018686:Anesthetics, Intravenous; D012709:Serum Albumin; D015742:Propofol