Young GA, Hong O, Khazan N. Differential tolerance to repeated daily injections of N-allylnormetazocine and its enantiomers in the rat.
Neuropharmacology 1987;
26:463-7. [PMID:
3037416 DOI:
10.1016/0028-3908(87)90028-1]
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Abstract
This study was designed to compare the development of tolerance to the effects of N-allylnormetazocine (SKF-10,047) and its enantiomers on the EEG and on behavior. Adult female Sprague-Dawley rats were implanted with chronic cortical electroencephalogram (EEG) and electromyogram (EMG) recording electrodes in the temporalis muscle and with permanent cannulae in the external jugular vein. In non-tolerant rats, 10 mg/kg (i.v.) injections of SKF-10,047 racemate produced primarily aroused wakefulness for about 120 min, that was associated with alternation between desynchronized EEG and theta waves in the EEG. After these rats received a series of automatic, intravenous injections of SKF-10,047 racemate, the aroused wakefulness state induced by SKF-10,047 racemate lasted for about 40 min. In non-tolerant rats, 2.5 mg/kg (i.v.) injections of (+)-SKF-10,047 induced a psychotomimetric EEG and behavioral state for about 30 min, which included continuous theta wave activity in the EEG. After chronic treatment with (+)-SKF-10,047, the psychotomimetic state induced by (+)-SKF-10,047 persisted for about 20 min. In non-tolerant rats, 2.5 mg/kg (i.v.) injections of (-)-SKF-10,047 produced an aroused EEG and behavioral wakefulness for about 30 min, which was then followed by slow-wave bursts in the EEG and associated behavioral stupor for about 90 min. After chronic treatment with (-)-SKF-10,047, injection of (-)-SKF-10,047 produced predominantly aroused wakefulness for about 45 min. The data suggest that (+)-SKF-10,047 exerts psychotogenic properties, but not opioid properties. On the other hand, the data suggest that (-)-SKF-10,047 possesses opioid properties.
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