Lack of effect of flurothyl, a non-anesthetic fluorinated ether, on rat brain synaptic plasma membrane calcium-ATPase

Plasma membrane Ca2+-ATPase (PMCA), a regulator of intracellular calcium, i s inhibited by volatile anesthetics and by xenon and nitrous oxide. Respons e of a cellular system to anesthetics, particularly to volatile agents, rai ses the question of non-specific, even toxic, side effects unrelated to ane sthetic action. Compounds with chemical and physical properties similar tb halogenated anesthetics, but which lack anesthetic effect, have been used t o address this question. We have compared the effects of halothane and flur othyl, a non-anesthetic fluorinated ether, on PMCA Ca2+ transport across is olated brain synaptic plasma membranes (SPM). Flurothyl, at concentrations predicted by the Meyer-Overton curve to range from 0.4 to 2.6 MAC (minimum alveolar concentration), had no significant on PMCA activity. In contrast h alothane, 1.3 MAC, reduced Ca2+ transport 30 to 40%. These findings provide further evidence for a specific effect of inhalation anesthetics on neuron al plasma membrane Ca2+-ATPase. (C) 1999 Elsevier Science Inc.