Lithium Potentiates the FeCl₂ Induced Free Radical Injury in Primary Mouse Cortical Cell Culture

Abstract

Objectives : For the past half century, lithium has been used for the acute and prophylactic treatment of bipolar disorder and recurrent depression. Recently, new pharmacological effects of Li+ have appeared, showing that Li+ can influence neuronal injury. We tested the effects of Li+ on free radical induced neuronal injury in primary murine cortical cell cultures.

Methods : Cortical cells were prepared from fetal mice (embryonic day 15) and exposed to 30 μM Fe²+ alone or with 5 mM Li+ or 5 mM Li+ alone for 24 hrs at Days in vitro (DIV) 14. Neuronal death was analyzed by measuring lactate dehydrogenase (LDH) release into media. The fluorescence of 2’,7’-dichlorofluorescin (DCF) was measured in as a mean of estimating the formation of reactive oxygen species (ROS).

Results : Li+ alone does not produce neuronal injury itself but it potentiates Fe²+-induced neuronal injury through increasing the production of free radical. Conclusion : This study suggests that the effects of Li+ on neuronal survivorship may be injury type dependent and Li+ potentiate the free radical injury. Therefore in practice clinician should be cautious in using the lithium in the treatment of brain injured patients.