Evaluation of histamine-releasing property of propofol in whole blood in vitro.

We examined the property of emulsion form of propofol (ICI 35 868) to release histamine in whole blood in vitro. Heparinized whole blood from 10 healthy volunteers were incubated with medium and propofol at the final concentration of 0, 1, 10 and 100 microg.ml(-1). The concentration of histamine in supernatant fluid after incubation was measured by radioimmunoassay. Histamine release was expressed as the percentage of the concentration of histamine released into supernatant fluid relative to the total cellular histamine content, which was yielded by destroying cell components in the whole blood. Histamine release in the presence of propofol at the concentrations of 1, 10 and 100 microg.ml(-1) were almost the same as histamine release in the absence of propofol. We conclude that emulsion form of propofol has no property to release histamine in whole blood in vitro.