Modulation of peripheral opioid receptors affects the concentration of mu-opioid receptors in rat brain.
Radioligand binding assay was used to evaluate characteristics of central mu-opioid receptors after peripheral administration of mu-opioid receptor agonist loperamide and antagonist methylnaloxone. These substances do not cross the blood-brain barrier. Loperamide and methylnaloxone produced opposite effects on the density of mu-opioid receptors in the frontal cortex of rat brain. These data confirm our hypothesis on reciprocal interactions between central and peripheral compartments of the endogenous opioid system.
Proskuryakova
T V
TV
P K Anokhin Institute of Normal Physiology, Russian Academy of Medical Sciences, Moscow, Russia.
Shokhonova
V A
VA
Chumakova
Yu A
YA
Bashkatova
V G
VG
Sudakov
S K
SK
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D008139:Loperamide / Q000494:pharmacology; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000378:metabolism; D009270:Naloxone / Q000031:analogs & derivatives / Q000494:pharmacology; D009292:Narcotic Antagonists; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011957:Receptors, Opioid / Q000819:agonists / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*
D009292:Narcotic Antagonists; D000644:Quaternary Ammonium Compounds; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; D009270:Naloxone; D008139:Loperamide; C041269:N-methylnaloxone