Opioid Receptor (Paperback)

High Quality Content by WIKIPEDIA articles High Quality Content by WIKIPEDIA articles Opioid receptors are a group of G protein-coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins and nociceptin. The opioid receptors are 40% identical to somatostatin receptors (SSTRs).By the mid-1960s, it had become apparent from pharmacologic studies that opiate drugs were likely to exert their actions at specific receptor sites, and that there were likely to be multiple such sites. The receptors were first identified as specific molecules through the use of binding studies, in which opiates that had been labeled with radioisotopes were found to bind to brain membrane homogenates. The first such study was published in 1971, using 3H-levorphanol. In 1973, Candace Pert and Solomon H. Snyder published the first detailed binding study of what would turn out to be the opioid receptor, using 3H-naloxone. That study has been widely credited as the first definitive finding of an opioid receptor, although two other studies followed shortly after.