The pressure reversal of a variety of anesthetic agents in mice.
The aim of this work was to study in mammals the ability of high pressures to reverse the anesthesia produced by a wide range of general anesthetics. Dose-response curves were obtained using mice at pressures ranging from 1 to 125 atm for five agents, namely alpha-chloralose, ethylcarbamate, phenobarbital and, for comparison, nitrogen and argon. The increase of ED50 was found to be a linear function of pressure in each case, but the proportionate increases in ED50 with pressure were greater for the three non-inhalation agents than for the two gases. Thus, the ratio of ED50 at 100 atm to that at 1 atm was 1.74 for alpha-chloralose, 1.68 for ethylcarbamate, and 1.54 for phenobarbital. On the other hand, the corresponding ratios for argon and nitrogen were only 1.36 and 1.34. The potencies of three short-acting agents (trichloroethanol, ketamine, and alphadione) were shown to increase with decreasing pressure, although ED50 values could not be obtained. It is concluded that pressure reverses the actions of a wide variety of anesthetics in mice. The results of this study are not inconsistent with either the fluidized lipid membrane or the critical volume hypotheses of anesthetic action.
D000530:Alfaxalone Alfadolone Mixture; D000768:Anesthesia, General; D000777:Anesthetics; D000818:Animals; D001274:Atmospheric Pressure; D002698:Chloralose; D002728:Chlorohydrins; D004305:Dose-Response Relationship, Drug; D005023:Ethylene Chlorohydrin / Q000031:analogs & derivatives; D007649:Ketamine; D008297:Male; D051379:Mice; D010634:Phenobarbital; D014520:Urethane
D000777:Anesthetics; D002728:Chlorohydrins; D002698:Chloralose; D014520:Urethane; D007649:Ketamine; D005023:Ethylene Chlorohydrin; D000530:Alfaxalone Alfadolone Mixture; C005849:2,2,2-trichloroethanol; D010634:Phenobarbital