Astrocyte opioid receptors: activation modifies the noradrenaline-evoked increase in 2-[14C]deoxyglucose incorporation into glycogen.

Astrocyte-enriched cultures of the newborn rat cortex accumulated 2-[14C]deoxyglucose (2-DG), a proportion portion of which was incorporated into glycogen. Exposure to exogenous noradrenaline resulted in an increase (30%) in the incorporation of 2-[14C]DG into glycogen in these cultures. The extent to which noradrenaline evoked an increase in 2-[14C]DG labelling of glycogen was modified by both morphine and methionine-enkephalin. Whereas morphine augmented the noradrenaline-induced increase in 2-[14C]DG incorporation into glycogen in these cultures, methionine-enkephalin attenuated this response.