CHOLINERGIC DIFFERENTIATION FACTOR LEUKEMIA INHIBITORY FACTOR (CDF LIF) INCREASES CHOLINERGIC BUT NOT ENKEPHALIN-IMMUNOREACTIVE CELLS IN ADRENAL-MEDULLA GRAFTED TO THE RAT HIPPOCAMPUS/

The effects of Cholinergic Differentiation Factor/Leukemia Inhibitory Factor (CDF/LIF) on the transmitter phenotype was investigated in the chromaffin cells of adrenal medulla grafts implanted in the hippocampu s of adult rats. In the grafted rats treated once or twice with CDF/LI F, the evolution of the chromaffin cells from a catecholaminergic to a cholinergic phenotypes was facilitated. The number of chromaffin cell s immunoreactive to choline acetyltransferase (ChAT) was significantly higher in CDF/LIF-treated than control rat grafts, a parallel signifi cant decrease occurred in the number of chromaffin cells immunoreactiv e to phenylethanolamine-N methyltransferase (PNMT). However, the numbe r of chromaffin cells immunoreactive to the octapeptide M(5)-Arg-Phe-G ly (MetEnk 8) was not significantly different in grafts from LIF-treat ed and control rats, suggesting that LIF had no effects on the synthes is of this octapeptide. The fact that LIF facilitates the acquisition of cholinergic phenotypes by chromaffin cells in adrenal medulla graft s implanted in an adult brain, may have important therapeutic applicat ion.