Friedrich Hoffmeister

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Heroin, codeine, dextropropoxyphene, and pentazocine were compared using a drug-maintained progressive-ratio procedure in the rhesus monkey. Infusions of the drugs were contingent on completion of increasing fixed ratio (FR) response requirements with variable time-out periods following each infusion. Prior to drug experiments, stabile self-infusion(More)
The stimulus effects of codeine were assessed in three monkeys trained to perform first under the contingencies of a cross self-administration paradigm and then under a two lever discrimination task. Codeine-trained monkeys generalized to pentazocine, buprenorphine, and codeine under both procedures in doses different from the training dose. Codeine-trained(More)
Rhesus monkeys were conditioned to press a key to selfadminister intravenous injections of either cocaine (8 monkeys) or codeine (7 monkeys). Every tenth lever press resulted in an injection of 50 mcg/kg/inj. cocaine or codeine during daily 3 h sessions. Equal doses of cocaine and codeine generated regular comparable rates of self-administration responding.(More)
Neuro- and psychopharmacological effects of isopropyl-(2-methoxy-ethyl)-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (Bay e 9736, nimodipine) are described using a variety of methods measuring behavior under normal conditions, under the influence of psychotropic drugs, as well as under the influence of ischemia or hypoxia. It has(More)
The calcium antagonist dihydropyridine derivative nimodipine and its enantiomers BAY N 5247, BAY N 5248, as well as BAY R 4407 (calcium antagonist (+)-enantiomer of the calcium agonist dihydropyridine BAY K 8644) do not exert antinociceptive effects in the rat as measured by the vocalization test in doses up to 100 μg/kg IV, and in the mouse as measured by(More)