Effects of repeated administration of a kappa-opioid agonist on phorbol ester binding to membrane-bound protein kinase C in rat brain.
The dissociation constant (KD) of [3H]phorbol 12,13-dibutyrate (PDBu) binding to protein kinase C (PKC) in membranes of rat cortex and midbrain was significantly decreased with no change in the receptor density (Bmax) following 7-d treatment with a kappa-opioid agonist, U-50,488 (20 mg/kg/d, i.p.). Neither the Bmax nor KD values in pons/medulla were altered by repeated U-50,488 treatment. These results suggest that repeated administration of a kappa-opioid agonist increases the affinity for PDBu binding to the membrane-bound PKC in rat cortex and midbrain, but not in pons/medulla.
Feng
Y
Y
Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson 39216, USA.
Narita
M
M
Makimura
M
M
Hoskins
B
B
Ho
I K
IK
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000818:Animals; D001921:Brain / Q000201:enzymology*; D008297:Male; D015240:Phorbol 12,13-Dibutyrate / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017473:Receptors, Opioid, kappa / Q000819:agonists*
D011759:Pyrrolidines; D017473:Receptors, Opioid, kappa; D015240:Phorbol 12,13-Dibutyrate; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D011493:Protein Kinase C