Fig. 5. Displacement analysis of [3H]QNB binding to cell membranes of myocytes by propofol. [3H]QNB (0.1 nM), cell membranes of myocytes, and competing unlabeled drugs (atropine, propofol, and Intralipos) were incubated together for 45 min at room temperature. The values of IC50and dissociation constants (Ki) for atropine and propofol displacement of [3H]QNB binding were 8.5 ± 0.6 nM and 3.4 ± 0.2 nM, and 320 ± 10 μM and 130 ± 10 μM, respectively. Intralipos did not displace [3H]QNB binding.