Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2000 Apr;267(8):2354-61.
doi: 10.1046/j.1432-1327.2000.01239.x.

Morphine-like Substance in Leech Ganglia. Evidence and Immune Modulation

Affiliations
Free article

Morphine-like Substance in Leech Ganglia. Evidence and Immune Modulation

V Laurent et al. Eur J Biochem. .
Free article

Abstract

Binding experiments followed by measurement of nitric oxide release revealed an opiate alkaloid high affinity receptor with no affinity to opioids, representing a new mu-subtype receptor in the brain of the leech Theromyzon tessulatum. In addition, evidence of morphine-like substances was found in immunocytochemical studies and HPLC coupled to electrochemical detection (500 mV and 0.02 Hz). Based on previous evidence of the involvement of morphine as an immune response inhibitor, we demonstrate that in leech ganglia injection of lipopolysaccharide (LPS; a potent immunostimulatory agent derived from bacteria) provoked an increase in the level of ganglionic morphine-like substances after a prolonged latency period of 24 h (from 2.4 +/- 1.1 pmol per ganglion to 78 +/- 12.3 pmol per ganglion; P < 0.005; LPS injected 1 microg x mL-1); this effect is both concentration- and time-dependent. Finally, we have demonstrated that morphine, after binding to its own receptor, inhibits leech immunocyte activation through adenylate cyclase inhibition and nitric oxide release. This report confirms that morphine is an evolutionarily stable potent immunomodulator.

Similar articles

See all similar articles

Cited by 1 article

Publication types

LinkOut - more resources

Feedback