Cellular dopamine is increased following exposure to a factor derived fromimmortalized striatal neurons in humans

A factor obtained from an immortalized hybrid monoclonal cell line (X61) of striatal origin is capable of increasing the dopamine content of hybrid, m onoclonal cells expressing a dopaminergic phenotype (MN9D) and of aggregate cultures containing primary dopaminergic neurons. The factor is a protein smaller than 100 kDa and appears to be different th an a number of other tr ophic agents with effects on the dopaminergic neuron. The effect on dopamin e content appears to be specific to centrally-derived neuronal elements; th e protein having no effect on the dopamine content of PC12 cells. Given tha t parkinsonian symptoms are only apparent following degeneration of a subst antial portion of the mesencephalic dopaminergic cell population, activity capable of increasing dopamine content of the surviving cells may represent an interesting candidate therapeutic agent. (C) 2000 Elsevier Science Irel and Ltd. All rights reserved.