The mechanism of action of these substances is mediated by binding and activation of their eponymous G-protein receptors,
The mechanism of action of these substances is mediated by binding and activation of their eponymous G-protein receptors, of which three classses have been identified: mu, delta, and kappa. Capable of constriction of the pupils and suppression of the cough reflex, endogenous forms of these substances are produced from cleavage of peptides such as POMC, and include the dynophins, enkephalins, and endorphins. Antagonized by naloxone, the mu receptors in the dorsal horn of spinal cord mediates its major effects, which is to hyperpolarize and inactivate postsynaptic neurons that transmit pain. FTP, name this class of substances, examples of which include methadone, codeine, heroin, and its prototype, morphine.
The mechanism of action of these substances is mediated by binding and activation of their eponymous G-protein receptors,
opiates or opioids (grudingly accept narcotics)