Endogenous morphine

Abstract

It is now well accepted that endogenous morphine is present in animals, both in invertebrates and vertebrates. It is a key signaling molecule that plays an important role in downregulating physiological responses, such as those in the immune system, including immune elements in the CNS. It has been demonstrated that a specific mu-opiate-receptor subtype, mu3, mediates these downregulatory effects through release of NO. This article examines morphine as an endogenous signaling molecule, in terms of its role in neural and immune regulation.

Topography of social touching depends on emotional bonds between humans

“…Primate studies suggest that the rewarding effects of pleasurable touching and the consequent modulation of anxiety-related behaviors are governed by the endogenous μ-opioid system (27), well known for its role in governing analgesic responses (28) and pleasurable sensations (29). In primates, opioid-receptor antagonists increase the frequency of grooming (27,30) and grooming solicitations (31) irrespective of the dyadic relationship (32).…”

Oral Administration of Lactoferrin Inhibits Inflammation and Nociception in Rat Adjuvant-Induced Arthritis

“…However, the anti-nociceptive activity of LF in the periphery is still unclear. As exogenous and endogenous opioids produced both central and peripheral anti-nociception [18,19], BLF and endogenous LF may cause analgesia not only in the CNS [11] but also in the periphery via the opioidergic system. Further investigation is required to clarify this point.…”

Opioid Induced Constipation

“…In the gastrointestinal tract, μ-receptors are widely distributed in the submucosa (10), as well as in the ileal mucosa. They influence ion transport changes (11). While μ -and κ -opiate receptors are more representative in stomach and proximal colon (12).…”