Effect of helium on membrane resistance.

Resistance measurements were made of bimolecular lipid membranes (BLM) according to Mueller and Rudin (10). With the addition of excitability inducing material (EIM), a bacterial protein, the electrical resistance of the BLM was reduced to within biological limits. Frog pericardium was used in the same system as a natural membrane comparison. Exposure of these membranes to air, oxygen and nitrogen resulted in no significant change in the resistance of the bilayers or the pericardium. Exposure to helium and helium 79%-oxygen 21% mixutre resulted in a significant increase in the membrane resistance.