Morphine and related µ-opioid receptor (MOR) agonists remain among the most effective
drugs known for acute relief of severe pain. A major problem in treating painful conditions is …

The ability of morphine to alleviate pain is mediated through a heterotrimeric guanine
nucleotide binding protein (G protein)–coupled heptahelical receptor (GPCR), the μ opioid …

▪ Abstract Opioid receptors belong to the large superfamily of seven transmembrane-
spanning (7TM) G protein-coupled receptors (GPCRs). As a class, GPCRs are of …

The opioid system modulates several physiological processes, including analgesia, the
stress response, the immune response and neuroendocrine function. Pharmacological and …

Although opioids are highly effective for the treatment of pain, they are also known to be
intensely addictive. There has been a massive research investment in the development of …

▪ Abstract G protein–coupled receptors (GPRs) play a key role in controlling hormonal
regulation of numerous second-messenger pathways. However, following agonist activation …

Seven-transmembrane receptors (7TMRs), the most common molecular targets of modern
drug therapy, are critically regulated by β-arrestins, which both inhibit classic G-protein …

Cloning of multiple opioid receptors has presented opportunities to investigate the
mechanisms of multiple opioid receptor signaling and the regulation of these signals. The …

A large range of neuroadaptations develop in response to chronic opioid exposure and
these are thought to be more or less critical for expression of the major features of opioid …