[The analgesic activity of coordination compounds of methionine enkephalin with divalent metals].

Coordination compounds of methenkephalin with transition metals: copper, cobalt, nickel and zinc were shown to be superior to morphine by the analgesic activity and to morphine and methenkephalin by the duration of the analgesic effect. A more stable relationship between opiate receptors and copper-containing methenkephalin was shown in the experiments on the isolated neuronal membrane.