Sándor Hosztafi

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The present study examined the pharmacology of dihydromorphine, 6-acetyldihydromorphine and dihydroheroin (3,6-diacetyldihydromorphine). Like morphine, dihydromorphine and its acetylated derivatives all were highly selective mu-opioids in receptor binding assays. All the compounds were potent mu-selective analgesics, as shown by their sensitivity towards(More)
This study compared the peripheral analgesic effects of a novel opioid agonist 14-O-methylmorphine-6-O-sulfate (14-O-MeM6SU), to that of non-peptide (morphine, fentanyl) and peptide opioid agonists (Met-enkephalin; met-ENK and β-endorphin; β-END) in a model of localized inflammatory pain evoked by intraplantar (i.pl.) Freund's complete adjuvant (FCA).(More)
The therapeutic use of opioids is limited by the development of tolerance to the analgesic effect and the cellular and molecular mechanisms underlying this phenomenon are still not completely understood. For this reason the search for new analgesic derivatives, endowed with lower tolerance, is always an active field. The newly synthesized(More)
The aims of this study were to synthesize 14-O-Methylmorphine-6-O-sulfate (14-O-MeM6SU) and examine its opioid properties (potency, affinity, efficacy) in receptor ligand binding and isolated tissues (mouse vas deferens, MVD and rat vas deferens, RVD bioassays). The results were then compared to the parent compounds morphine-6-O-sulfate (M6SU) and morphine,(More)
Highly selective heterocyclic opioid ligands with potent delta-antagonist activity have been developed on the basis of the "message-address" concept. Using this strategy, benzofuran derivatives corresponding to the non-selective opioid antagonist, naloxone, and to the mu-opioid receptor selective agonists, oxymorphone and oxycodone, were synthesized. In(More)
Previous work from our lab identified two subtypes of the opioid kappa receptor. Whereas the kappa1 receptor can be labeled by [3H]U69,593 (5 alpha,7 alpha,8 beta-(-)- N-methyl-N-[7-(1-pyrrolidinyl)-1-oxaspiro(4,5)dec-8-yl]-phenyl- benzeneacetamide), the kappa2 receptor can be labeled by [125I]OXY (6 beta-125iodo-3,14-dihydroxy-17-cyclopropylmethyl-4,5(More)
(-)[N-(propyl)-14-OH-dihydromorphinan-6-one] = (N-propyl)-noroxymorphone and its multiple tritiated form (molar activity: 126 Ci/mmol; 1 Ci = 37 GBq) was synthesized. According to our knowledge this specific radioactivity exceeds all of the commercially available [3H]opioid ligands. The ligand was found to be a pure opioid antagonist in receptor binding(More)
Oxymorphazone (at doses of 50-200 mg/kg) was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone (200 mg/kg) administration. The ligand increased the latency of wiping reflex in spinal frogs too. These effects were(More)
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