Gap junction uncoupling of neonatal rat astroglial cultures does not affect their expression of fibroblast growth factor 2

Fibroblast growth factor (FGF)-2 is expressed by astroglial cells and regul ates astroglial proliferation, differentiation, and gap junction communicat ion. We show now that uncoupling of astroglial cells cultured from neonatal rat cortex, striatum and mesencephalon by 18 alpha-glycirrhetinic acid (AG A) or arachidonic acid (AA) (demonstrated by intracellular injections of Lu cifer Yellow) does affect neither levels of FGF-2 mRNA (investigated by a c ompetitive RT-PCR method), nor protein (as revealed by Western blot analysi s). This suggests that expression of FGF-2, which reduces gap junction comm unication of cortical and striatal astroglial cells [15], is not affected w hen astroglial cells are uncoupled. Regulation of FGF-2 expression and coup ling in astroglial cells are thus not reciprocal suggesting more complex in terrelationships between these two important parameters of astroglial cell differentiation. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved .