ELECTROPHYSIOLOGICAL AND BIOCHEMICAL-EVIDENCE FOR BRADYKININ RECEPTORS ON CULTURED RAT CORTICAL OLIGODENDROCYTES

The effects of the neuropeptide bradykinin (Bk) were examined on antigenically-identified rat cortical oligodendrocytes. Bk significantly increased the incorporation of [H-3]myo-inositol into phospholipids, indicating the turnover of phosphatidyl inositol (PI). Ca2+ flux analysis experiments confirmed that this effect was accompanied by an increase in intracellular Ca2+. Using the whole-cell patch clamp technique, Bk was shown to induce an inward current associated with a decrease in membrane conductance, indicating a closure of ion channels. The reversal potential of the current was close to the potassium equilibrium potential, consistent with an effect on a K+ conductance in these cells. These results show that oligodendrocytes possess Bk receptors that may be of functional relevance.