Morphine is a powerful pain reliever, but also a potent inducer of tolerance and
dependence. The development of opiate tolerance occurs on continued use of the drug such …

A variety of second messenger systems have been implicated in the intracellular
mechanisms of tolerance development to the analgesic actions of morphine, a mu opioid …

Introduction 3. Opioid receptor signaling 3.1. Receptor phosphorylation by protein kinase C
3.2. Modulation of receptor internalization by protein kinase C 3.3. PKC hypothesis for …

Despite the existence of a large body of information on the subject, the mechanisms of
morphine tolerance and dependence are not yet fully understood. There is substantial …

Acute morphine administration produces analgesia and reward, but prolonged use may lead
to analgesic tolerance in patients chronically treated for pain and to compulsive intake in …

Each year, over 50 million Americans suffer from persistent pain, including debilitating
headaches, joint pain, and severe back pain. Although morphine is amongst the most …

δ-Opioid receptor (DOPr) activation fails to produce cellular physiological responses in
many brain regions, including the periaqueductal gray (PAG), despite neural expression of …

Despite the demonstration that chronic morphine increases phosphorylation of multiple
substrate proteins, their identity has, for the most part, remained elusive. Thus far, chronic …

The generation of potent opioid analgesics that lack the side effects of traditional opioids
may be possible by targeting truncated splice variants of the μ-opioid receptor. μ-Opioids act …

Chronic treatment with morphine results in a decrease in μ-opioid receptor sensitivity, an
increase in acute desensitization, and a reduction in the recovery from acute desensitization …