Figure 1

Summary of ion channel modulation as a function of calculated anesthetic molar solubility in unbuffered water at 25°C (values from SciFinder Scholar). Drugs that modulate 4-transmembrane receptors (TM4) or neither receptor type are shown as open circles (○, A-F) below the dotted horizontal solubility line. Drugs that modulate both 3-transmembrane (TM3) and TM4 receptors are shown as small black circles (●, G-U) above the dotted horizontal solubility line. A = nonane (unpublished data), B = midazolam [9], C = diazepam [10], D = undecanol [11], E = etomidate [12], F = 1,2-dichlorohexafluorocyclobutane [13], G = sevoflurane [14–17], H = propofol [18, 19], I = ketamine [12, 16, 20], J = isoflurane [14–16, 21, 22], K = enflurane [15, 23], L = dizocilpine [20, 24], M = desflurane [16, 17], N = halothane [14, 22, 23], O = cyclopropane [22, 25], P = chloroform [22], Q = 2,6-dimethylphenol [26], R = methoxyflurane [14, 15, 23], S = diethyl ether [15, 23], T = nitrous oxide [21, 22], U = ethanol [21].