Fig. 6.
The effect of anesthetic combinations on open probabilities of TASK-1 expressed in HEK293 cells. Compare with figure 2. Halothane 2.5% (single red symbol) activates TASK-1 channels to just under 120% (see also fig. 5B). At this constant background level of 2.5% halothane (red symbol), progressively increasing concentrations of isofurane were added to the mix in concentrations of 1.5%, 2.5%, 4%, and 5% in separate experiments (green symbols). Also for clarity (purple), the plotted line is shown from Equation 1 for ligand binding copied from figure 5B for isoflurane, to show that as isoflurane is added to the mix, the result tends toward that for isoflurane alone, and not away from it. The green line is the line plotted from Equation 2, using the estimated values of Bmax and Kd for halothane and isoflurane. Each symbol is mean ± SD, n = 30 paired recordings in separate cells for the mix line. See Supplementary Digital Content, figure S5 (https://links.lww.com/ALN/C467), for the data plotted against aqueous concentrations. nPopen, product of the number of channels in the patch and the probability of a channel being open.