The effect of prozac on whole cell ionic currents in lens and
corneal epithelia.
Rae, James L., Adam Rich, Aldo C. Zamudio, Oscar A. Candia.
Departments of Physiology and Biophysics and Ophthalmology, Mayo
Foundation, Rochester, MN 55905, Department of Ophthalmology, Mount
Sinai School of Medicine, New York, NY 10029-6574
APStracts 2:0082C, 1995.
Prozac (fluoxetine), a compound used therapeutically in humans to
combat depression, has substantial effects on ionic conductances in
rabbit corneal epithelial cells and in cultured human lens
epithelium. In corneal epithelium, it reduces the current due to the
large conductance potassium channels which dominate this preparation.
It's effects seem largely to decrease the open probability while
leaving the single channel current amplitude unaltered. In cultured
human epithelium, currents from calcium-activated potassium (BK)
channels and inward rectifiers are unaffected by Prozac. Delayed
rectifier potassium currents are reduced by Prozac in a complicated
way which involves both gating and single channel current amplitude.
Fast TTX blockable sodium currents are also decreased by Prozac in
this preparation. For all of these ion conductance effects, Prozac
concentrations of 10-5 to 10-4 M are required. While these levels are
10-100 fold higher than the plasma levels achieved in therapeutic use
in humans, they are comparable to or less than levels needed for many
other blockers of the ionic conductances studied here.
Received 31 May 1994; accepted in final form 12 January 1995.
APS Manuscript Number C293-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 28 February 1995.