2-deoxy-D-(14C)-glucose study of the interaction of caerulein and apomorphine

The interaction of ceruletide (CER) and apomorphine (APO) was studied in mice. APO and CER were injected subcutaneously. In wheelcage experiments, lower doses (50 to 100 micrograms/kg) of APO depressed dose-dependently the locomotor activity in mice, but a higher dose (1 mg/kg) of APO produced a smaller effect than 100 micrograms/kg of APO. CER (20 micrograms/kg) slightly depressed the locomotor activity in mice. The coadministration of APO and CER caused stronger inhibition in the locomotor activity than the single administration of these drugs. The effects of APO and CER on the neuronal uptake of 2-deoxy-D-(14C)-glucose (2-DG) were also examined. APO (50 and 1000 micrograms/kg) inhibited the 2-DG uptake in most regions of the brain, although the inhibitory effect was larger at lower doses. CER inhibited the 2-DG uptake in some regions, but enhanced it in others. The combination of APO and CER markedly enhanced the 2-DG uptake. Thus, it was difficult to correlate the effects of the combination of APO and CER on locomotor activity with 2-DG uptake.