Regulation of mu binding sites after chronic administration of antibodies directed against specific anti-opiate peptides.
There is some indication that anti-opiate peptides (AOP) modulate opioid receptor systems by altering mu-receptor density. To further characterize this phenomenon, we investigated the effects of continuous infusion of anti-AOP IgG on mu binding sites in the brains of rats. Specifically, male Sprague-Dawley rats received intracerebroventricular (i.c.v.) infusions for 13 days of either control (rabbit) IgG or test IgGs: anti-dynorphin A IgG, anti-dynorphin A1-8 IgG, anti-alpha-MSH IgG, or the monoclonal anti-NPFF IgG. Administration of anti-NPFF IgG or the anti-dynorphin1-8 IgG significantly increased mu labeling by 40-70% in several brain regions at the caudate level. Contrary to these findings, anti-alpha-MSH IgG decreased (19-32%) [125I]-DAMGO labeling in several thalamic nuclei. The results suggest that the density of mu-opioid receptors is regulated in part by anti-opiate peptides in the extracellular fluid of the brain.
Goodman
C B
CB
College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, USA. cgoodman@famu.edu
Heyliger
S
S
Emilien
B
B
Partilla
J S
JS
Yang
H Y
HY
Lee
C H
CH
Cadet
J L
JL
Rothman
R B
RB
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D001665:Binding Sites; D001923:Brain Chemistry; D004399:Dynorphins / Q000276:immunology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins; D000939:Epitopes / Q000187:drug effects / Q000276:immunology / Q000528:radiation effects; D007074:Immunoglobulin G / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology; D007276:Injections, Intraventricular; D007457:Iodine Radioisotopes; D008297:Male; D018847:Opioid Peptides / Q000276:immunology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000378:metabolism* / Q000502:physiology; D000521:alpha-MSH / Q000276:immunology
D000888:Antibodies, Anti-Idiotypic; D004745:Enkephalins; D000939:Epitopes; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes; D018847:Opioid Peptides; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D000521:alpha-MSH; D004399:Dynorphins