The cardiovascular effects of opioid peptides may be associated with activation of opioid receptors located on the sarcolemma of cardiomyocytes, on the cell membrane of ICA and endothelial cells, on sympathetic and parasympathetic nerve terminals in the heart and in the adrenals. The cardiovascular effects of opioids penetrating the blood-brain barrier may be the result of their impact on central opioid receptors.