Fedor Medzihradsky

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The binding parameters of radiolabeled DAMGO (mu), DPDPE and pCl-DPDPE (delta) and 5 alpha, 7 alpha, 8 beta-N-methyl-N-[7-(1- pyrrolidinyl)-1-oxaspiro(4,5)dec-8-yl]benzeneacetamide (also known as U69593, kappa) and the affinity and selectivity profiles of various opioid agonists and antagonists at the three opioid receptor types were determined in membranes(More)
Rhesus monkeys were trained to respond under a fixed-ratio 30 schedule of food reinforcement. The mu opioid agonists alfentanil and fentanyl, the kappa opioid agonists ethylketocyclazocine (EKC) and U69,593, the delta opioid agonist BW373U86 [(+-)-4-((R*)-a-((2S*5R*)-4-allyl-2,5-dimethyl-1-piperazinal)-3-h ydroxy- benzyl)-N,N-diethylbenzamide(More)
In C6 glioma cells stably expressing a homogeneous population of the cloned rat mu opioid receptor, the binding affinities of opioid agonists and subsequent activation of G protein were examined. Opioid receptor number in membranes of these cells was high (10-30 pmol/mg protein [3H]diprenorphine binding sites). Opioids were found to bind to the receptor(More)
Bremazocine, [5R-(5,7,8 beta)]-N-methyl-N-[7-(1-pyrrolidinyl)1-oxaspiro [4,5]dec-8-yl]-4-benzofuranacetamide (Cl-977), (+-)-trans-3,4-dichloro-N- methyl-(2-(pyrrolidin-1-yl)-5-methoxy-1,2,3,4-tetrahydronapth++ +-1-yl benzeneacetamide methanesulfonate (DUP 747), ethylketocyclazocine (EKC), nalorphine, (+/-)-trans-N-methyl-N-[2-(1-(More)
In C6 glial cells stably expressing rat mu-opioid receptor, opioid agonist activation is negatively coupled to adenylyl cyclase through pertussis toxin-sensitive G proteins. In membranes, [D-Ala2, N-MePhe4,Gly-ol5]enkephalin (DAMGO) increases guanosine-5'-O-(3-[35S]thio)triphosphate (GTP[gamma-35S]) binding by 367% with an EC50 value of 28 nM. Prolonged(More)
The effects of the systemically active irreversible opioid receptor antagonist clocinnamox (C-CAM; 14 beta-(p-chlorocinnamoylamino)-7,8-dihydro-N- cyclopropylmethyl normorphinone mesylate) on mu receptor binding to cerebral membranes and on mu opioid analgesia were assessed using mice. After systemic administration, C-CAM produced a dose-dependent decrease(More)
A C6 glioma cell line stably transfected with the rat delta opioid receptor (C6delta) was used to characterize receptor binding and G protein activation by both peptide and nonpeptide delta opioid ligands. The ligand binding affinities for [3H]naltrindole and [3H]pCl-[D-Pen2,D-Pen5]enkephalin (DPDPE) were similar to those observed in monkey brain membranes.(More)
A C6 glioma cell line stably transfected with the human kappa opioid receptor (kappaOR) was used to characterize receptor binding and G protein activation via the kappaOR by a comprehensive series of opioid ligands. The ligand-binding affinity for [3H]5alpha,7alpha, 8beta(-)-N-methyl-N-(7-Cl-pyrrolidinyl)-1-oxaspiro(4, 5)dec-8-yl)benzene acetamide (U69593)(More)
A number of opiate antagonists and the dextro isomers of some of these drugs were studied for antagonism of acute opiate effects on ilea isolated from opiate-naive guinea pigs, precipitation of a withdrawal contraction of ilea isolated from morphine-dependent guinea pigs, precipitation of withdrawal in morphine-dependent rhesus monkeys and stereospecific(More)
In membranes from SH-SY5Y human neuroblastoma cells differentiated with retinoic acid, the mu-selective agonist Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol (DAMGO) inhibited cAMP formation with an IC50 of 26 nM. Two separate antibodies raised against distinct regions of the Go alpha sequence attenuated the effect of DAMGO by 50-60%, whereas antibodies to Gi alpha 1,2 or(More)