Experiments were performed on 33 white .male rabbits anaesthetized with chloralose and urethane under artificial venti1ation. The resu1ts were as follows: (1) depressor response could be evoked by electric stimulation of caudal ventrolateral medu1la (cVLM). The inputs of deep peroneal nerve (DPN)could inhibit partly the depressor response evoked by electric stimulation of cVLM (P<0.001 ). The regulation effects of DPN disappeared in 25～30 min. (2) after iv naIoxone (1. 5mg/kg) or microinjection of naioxone into rostral ventro1ateral medulla (rVLM) (2μg/1μl NS)

the inhibitory effect of DPN inputs was abolished partly(P<0. 01

P<0. 001 ).These results suggest that: (1 ) the depressor response elicited by cVLM excitation in rabbits can be regulated by inputs of DPN; (2) opiate peptide in rVLM may take part in the inhibitory effect of DPN inputs on depressor response excited by cVLM