Am J Psychiatry 1978; 135:1070-1078
Copyright © 1978 by American Psychiatric Association
A heritable disorder of lithium transport in erythrocytes of a subpopulation of manic-depressive patients
DG Ostrow, GN Pandey, JM Davis, SW Hurt and DC Tosteson
The in vivo RBC/plasma Li+ ratio is determined by the equilibrium between
Li+ influx (ouabain-sensitive Na+-K+ pump and ouabain- insensitive leakage
pathways) and Li+ efflux (phloretin-sensitive Li+- Na+ counterflow). A
study of RBC Li+ transport via these pathways showed that a deficiency of
Li+-Na+ counterflow was responsible for the high in vivo ratio (1:1)
observed in a manic patient. This defect was related to an alteration in
the membrane Na+ exchange system and was under genetic control. The level
of counterflow before lithium therapy was an excellent predictor (r = .88)
of the in vivo Li+ ratio and was deficient in approximately one-fourth of
manic-depressive patients but not in controls, schizophrenics, or unipolar
depressed patients.
