Selective Post-Translational Processing of Opioid Peptides in Cardioregulatory Mechanisms of the Dorsal Medulla

Abstract : The hypotensive properties of morphine and other opiate drugs have been well documented for over a century, yet only in the past two decades have we begun to understand the neuronal mechanisms responsible for these ofttimes deleterious effects. The history of these discoveries has been widely disseminated; stereoselective opioid receptors were first identified in the early 1970s followed soon thereafter by isolation of their endogeneous ligands, the opioid peptides beta-endorphin, met-and leu-en-kephalin, and dynorphin. All three opioid peptide families are expressed by neurons in the nucleus tractus solitrarius (NTS) and other cardioregulatory brain sites, providing an anatomical basis for the cardiovascular side effects of opiate drugs.