The role of intrinsic fluctuations of the membrane electric potential
(barrier height) in the active transport of ions through cell membrane
s is examined. Experimental data [D.-S. Liu et al., J. Biol. Chem. 265
, 7260 (1990)] on active transport of Na+ in human erythrocytes under
the influence of ac electric fields can be interpreted as the evidence
of stochastic resonance between the external field and the fluctuatio
ns of the membrane potential. The calculations show that in the consid
ered system one can expect also the appearance of aperiodic stochastic
resonance.