Erythrocyte membrane expansion due to the volatile anesthetics, the 1-alkanols, and benzyl alcohol

The extent to which semiturgid red cells could enter the tip of a glass micropipette of approximately 1-μm internal diameter was used to measure the area expansion of freshly drawn erythrocytes. The pipette was mounted in a gas-tight glass observation chamber so that one single cell at a time could be observed while it was being perfused, either with buffer alone or with buffer containing an anesthetic at physiologic concentration. The effect of the drugs was studied at room temperature at doses of 1, 2, and 4 times ED₅₀ for tadpoles. The drugs studied were: halothane, methoxyflurane, diethyl ether, fluroxene, isoflurane, hexanol, heptanol, octanol, decanol, dodecanol, tridecanol, tetradecanol, hexadecanol, and benzyl alcohol. The measured area expansion ranged between 0.13% and 0.62%. The measured expansion closely approximated the expansion expected by incorporation of the molecules. Tetradecanol and hexadecanol are not anesthetic to tadpoles, but they did expand the membrane. Therefore, expansion may not be related to anesthesia.