Some aspects of physiology and pharmacology of endogenous opioid peptides

The review, based largely on our own results describes the present state of knowledge of some aspects of opioid peptides and their physiological role. Studies on the effect of opioid peptides and opiates on brain function and the changes of brain level of endogenous opioids under various conditions have demonstrated, among others, the role of opioids in stress and stress-induced analgesia, the involvement of various opioid receptors in spinal mechanisms of analgesia, the inhibitory role of dynorphin in seizures in contrast to proconvulsant action of beta-endorphin system and mu receptor, and led to postulation of the role of beta-endorphin interaction with serotonin for ingestive behavior and a possible involvement of beta-endorphin system in the mechanism of action of antidepressant treatments.