OLEIC-ACID INHIBITS GAP JUNCTION PERMEABILITY AND INCREASES GLUCOSE-UPTAKE IN CULTURED RAT ASTROCYTES

The role of oleic acid in the modulation of gap junction permeability was studied in cultured rat astrocytes by the scrape-loading/Lucifer y ellow transfer technique. Incubation with oleic acid caused a dose-dep endent inhibition of gap junction permeability by 79.5% at 50 mu M, an d no further inhibition was observed by increasing the oleic acid conc entration to 100 mu M. The oleic acid-mediated inhibition of gap junct ion permeability was reversible and was prevented by bovine serum albu min. The potency of oleic acid-related compounds in inhibiting gap jun ction permeability was arachidonic acid > oleic acid > oleyl alcohol > palmitoleic acid > stearic acid > octanol > caprylic acid > palmitic acid > methyloleyl eater. Oleic acid and arachidonic acid, but not met hyloleyl ester, increased glucose uptake by astrocytes. Neither-oleic acid nor arachidonic acid increased glucose uptake in the poorly coupl ed glioma C6 cells. These results support that the inhibition of gap j unction permeability is associated with the increase in glucose uptake . We suggest that oleic acid may be a physiological mediator of the tr ansduction pathway leading to the inhibition of intercellular communic ation.