title: Physical dependence of opiate-like peptides.
abstract: Methionine-enkephalin and beta-endorphin, endogenous peptides with activities similar to those of opiates, were infused for 70 hours into the periaqueductal gray-fourth ventricular space of the rat brain. When challenged with a naloxone, a specific opiate antagonist, these animals manifested a typical morphine-like withdrawal syndrome. These results show that such peptides can cause physical dependence.
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects; D005625:Frontal Lobe; D006801:Humans; D008024:Ligands; D008297:Male; D009020:Morphine; D009270:Naloxone / Q000494:pharmacology; D009419:Nerve Tissue Proteins; D009842:Oligopeptides / Q000008:administration & dosage; D010455:Peptides / Q000008:administration & dosage; D051381:Rats; D013375:Substance Withdrawal Syndrome / Q000139:chemically induced; D019966:Substance-Related Disorders; D013997:Time Factors
chemical_list: D008024:Ligands; D009419:Nerve Tissue Proteins; D009842:Oligopeptides; D010455:Peptides; D009270:Naloxone; D009020:Morphine