Evidence for a role of dopaminergic mechanisms in the immunostimulating effect of mu-opioid receptor agonist DAGO.
The present study demonstrates that: (1) activation of micro -opioid receptors by systemic administration of a highly selective agonist DAGO (100 microg/kg) results in a significant increase in the number of plaque- and rosette-forming cells in the spleen of CBA mice as well as Wistar rats on the 5th day following sheep red blood cells (5 x 10(8)) immunization, (2) the immunostimulatory effect of DAGO is mediated by central mechanisms including the hypothalamus-hypophysis complex; (3) the postsynaptic dopamine (DA) receptors of D2 type are involved in the DAGO-induced immunostimulation since the combined treatment of animals with haloperidol (2 mg/kg), a blocker of DA D2 receptors, and DAGO abolished this effect; (4) the nuclei caudatus and accumbens of the nigrostriatal and mesolimbic DAergic systems, respectively, are implicated in the immune response stimulation caused by DAGO.
Devoino
Lidia
L
State Research Institute of Physiology of the Russian Academy of Medical Science, Siberian Branch, Novosibirsk, Timakova, Russian Federation.
Cheido
Margarita
M
Alperina
Elizaveta
E
Idova
Galina
G
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002529:Cerebellar Nuclei / Q000276:immunology / Q000293:injuries; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000494:pharmacology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology*; D004912:Erythrocytes / Q000276:immunology; D006220:Haloperidol / Q000494:pharmacology; D006462:Hemolytic Plaque Technique; D007031:Hypothalamus / Q000276:immunology / Q000293:injuries; D007114:Immunization; D007075:Immunoglobulin M / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D015213:Neuroimmunomodulation; D009714:Nucleus Accumbens / Q000276:immunology / Q000293:injuries; D010902:Pituitary Gland / Q000276:immunology / Q000293:injuries; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000819:agonists*; D012397:Rosette Formation; D012756:Sheep; D013045:Species Specificity; D013154:Spleen / Q000187:drug effects
D000701:Analgesics, Opioid; D018492:Dopamine Antagonists; D007075:Immunoglobulin M; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D006220:Haloperidol; D004298:Dopamine