Anders Neil

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The actions of d-propoxyphene and morphine on opioid receptor mechanisms were compared. In assay measuring receptor binding selectivity in vitro, with dihydromorphine, naloxone and an enkephalin analogue as radioactive ligands, d-propoxyphene differed from morphine in having a higher relative affinity for sites occupied by the peptide. Naloxone was more(More)
Binding sites for [3H]LTC4 were observed in crude membrane preparations of rat central nervous system tissue. Equilibrium binding studies indicated one high affinity [3H]LTC4 binding site with a KD of 31.4 +/- 3.4 nM for whole brain preparations. The binding was highly specific for [3H]LTC4 and could be inhibited by the SRS-A antagonist FPL 55172. Specific(More)
  • Anders Neil
  • 1982
Mice were rendered tolerant to morphine or l-methadone by subcutaneous injections for 4 days. The antinociceptive activities of morphine, codeine, l-methadone and d-propoxyphene were determined in tolerant and control mice using the hot-plate test, and the respective ED50's were calculated by the up-and-down procedure of Dixon. An asymmetry in(More)
The regional brain kinetics of the opioid receptor agonist, hydromorphone, labelled with 11C, were studied with positron emission tomography in two Macaque species. Rhesus and Cynomolgus monkeys. The plasma kinetics of 11C-hydromorphone was simultaneously determined. Rapid plasma elimination was obvious in both monkey species. Brain radioactivity was(More)
We have compared the effectiveness of morphine and methadone as agonists in untreated guinea-pig longitudinal muscle preparations and after their treatment with the specific opioid receptor alkylating agent beta-chloronaltrexamine. In untreated ilea, the naloxone pA2 was 8.5 to both morphine and methadone, and their dose-response curves were parallel. After(More)
A foot-shock titration method for the measurement of antinociceptive activity in the rat has been developed. A new grid design is described which makes the use of scrambled shocks unnecessary. Thresholds for responses elicited at different levels of integration within the central nervous system are measured: Detection threshold, flexor reflex, coordinated(More)
A series of five fluorescent opioid receptor probes was synthesized by coupling naloxone, oxymorphone or naltrexone with fluorescein or tetramethylrhodamine B. The series was characterized for capacity to displace 3H-dihydromorphine from rat brain opioid receptors. All compounds showed receptor binding, and 1-(N)-fluoresceinyl naltrexone thiosemicarbazone(More)
  • A. Neil
  • 1984
The selectivities of morphine, codeine, l-methadone and d-propoxyphene, towards the binding sites in mouse brain membranes labelled by 3H-dihydromorphine (DHM), 3H-ethylketocyclazocine (EKC) and 3H-D-Ala2-Leu5-enkephalin (DALE), were investigated. Of the four binding sites identified, three correspond to mu-, kappaand delta-opioid binding sites or(More)
Of two related Macaca species, the rhesus (M. mulatta), acquires opiate tolerance and dependence more readily than the cynomolgus (M. fascicularis). In the cynomolgus, mu-opiate receptors were significantly fewer in the caudate nucleus and globus pallidus; delta-sites were fewer in the thalamus. kappa-Sites showed no species difference. The levels of(More)
A method that enables the discrimination between binding models and the estimation of binding parameters, based solely on kinetic data, is described. Experimental data from association and dissociation experiments were fitted simultaneously to models with mono- or biphasic kinetics with the aid of a non-linear maximum likelihood computer program.(More)