Effects of prior exposure to morphine on the opioid inhibition of the stimulated release of [3H]norepinephrine from guinea pig cortex slices.
The potassium stimulated release of [3H]norepinephrine ([3H]NE) from terminal fields of locus coeruleus projections can be inhibited in a dose-dependent manner by mu and kappa selective opioids. Chronic exposure to morphine for six days decreases the maximum achievable depression by the mu selective agonist Tyr-D-Ala2-Gly-Me(Phe)-Gly-ol (DAGO), but has no effect on the degree of inhibition produced by the kappa selective opioid U50,488H.
Werling
L L
LL
Department of Pharmacology, Uniformed Services University, Bethesda, Maryland 20814.
Brown
S R
SR
Cox
B M
BM
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence / Q000503:physiopathology; D009638:Norepinephrine / Q000378:metabolism*; D011759:Pyrrolidines / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000502:physiology
D000700:Analgesics; D004745:Enkephalins; D011759:Pyrrolidines; D011957:Receptors, Opioid; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D009020:Morphine; D009638:Norepinephrine