Neurotoxic effects of chloroquine in vitro.

In order to investigate chloroquine retinopathy, the effect of chloroquine on the viability and differentiation of primary cell cultures of embryonic chick neuronal retina, retinal pigment epithelium (RPE), brain and meninges were investigated. The sensitivity of the cells, measured as reduction of viability, showed the following order: RPE greater than brain greater than meninges greater than neuronal retina. The human serum chloroquine concentration range which leads to ocular damage in vivo was identical to the concentration range in the culture medium which affected RPE viability. In addition, the differentiation of nerve cells in brain cell cultures was affected at much lower chloroquine concentrations than astroglia cells or nerve cells in neuronal retina cell cultures. Some possible mechanisms for chloroquine retinopathy were assessed.