This review discusses the criteria for determining whether a binding site or functional
response is directly mediated by either the mu, delta, or kappa opioid receptors. In 1988 …

Opioids are a group of analgesic agents commonly used in clinical practice. The three
classical opioid receptors are MOP, DOP and KOP. The NOP (N/OFQ) receptor is …

In inflammation, leucocytes containing opioid peptides migrate into the tissue. Opioid
peptides can be released and bind to opioid receptors on peripheral nerve terminals, which …

Opioids have long been thought to act exclusively within the central nervous system. An
increasing number of studies recently reported the existence of opioid receptors outside the …

Opioid alkaloids and peptides, such as morphine and the endogenous opioid peptides,
including β-endorphin and the dynorphin peptides, modulate the function of lymphocytes …

Highlights•Macrophages induce pain via pro-inflammatory cytokines that activate
nociceptors.•Nociceptor neurons activate local macrophages via TLR signaling and CCL2 …

Opioid receptors regulate neuronal activity by both pre-and postsynaptic mechanisms. We
recently reported that the cloned delta-opioid receptor (DOR1) is primarily targeted to axons …

One area that has emerged as a promising therapeutic target for the treatment and
prevention of chronic pain and opioid tolerance/hyperalgesia is the modulation of the central …

The nociceptin/orphanin FQ (N/OFQ) receptor (eg the human ortholog ORL1) has been
shown to be pharmacologically distinct from classic opioid receptors. Recently, we have …

Opioid receptors are expressed on peripheral sensory nerve endings, cutaneous cells, and
immune cells; and local application of opioids is used for the treatment of inflammatory pain …