Methscopolamine bromide - CAS 155-41-9

The effects of physostigmine and scopolamine were evaluated on working memory of rats in object recognition and radial-maze tests. Three doses of physostigmine hemi-sulfate (Phys: 0.05, 0.10 and 0.20 mg/kg), five doses of scopolamine hydrobromide (Scop: 0.125, 0.25, 0.5, 1.0 and 2.0 mg/kg), and one dose of scopolamine methylbromide (Mscop: 2.0 mg/kg) were used. In object recognition test, rats were submitted to three or four intertrial delay conditions (1-min, 15-min and either 60-min or 24-h). The higher doses of Scop (1.0 and 2.0 mg/kg) in 1-min and 15-min delay and of Phys (0.20 mg/kg) in 1-min delay impaired discrimination between new and familiar objects. Mscop impaired discrimination between objects in 60-min but not in 1-min and 15-min delay. This effect may be state dependent. Radial-maze learning was impaired by the lower doses of scopolamine (0.25 and 0.50 mg/kg) which had no effect in object recognition test. These results show that in our conditions, object recognition is less sensitive than radial-maze test to cholinergic drugs.

BACKGROUND AND OBJECTIVE: ;Evidence shows that acetylcholinergic transmission in the ventral tegmental area (VTA) or nucleus accumbens (NAc) plays an important role in heroin-seeking induced by cues. Cholinergic modulation of VTA neurons arises from the lateral dorsal tegmental nucleus (LDT). The present studies investigated the effect of systemic or intra- LDT administration of galantamine, an inhibitor of acetylcholinesterase, on heroin-seeking induced by cues.;METHODS: ;Rats were trained to self-administer heroin for 12 days, underwent extinction training for 12 days followed by two weeks in their home cages. Then the conditioned cues were introduced for the reinstatement of heroin-seeking.;RESULTS: ;The reinstatement of heroin-seeking induced by cues was attenuated by the administration of galantamine (0, 0.3, 1 or 3mg/kg, i.p.) in a dose-dependent manner. In contrast, galantamine only at the dose of 3mg/kg could inhibit the reinstatement of sucrose-seeking. Galantamine at those doses failed to alter the locomotor activity in heroin-withdrawn rats. The inhibition of drug-seeking by galantamine was reversed by pretreatment with scopolamine (0.5mg/kg) but not with mecamylamine (3mg/kg) or scopolamine methobromide (1mg/kg).

The effects of atropine on ventricular tachyarrhythmias induced by ligature of the anterior descending coronary artery were studied in conscious dogs. On the first day after surgery, animals received a mixture of quinidine and phenytoin orally in order to partially correct rhythm disturbances on the second day. The same animals were used on the third and fourth days after occlusion, when spontaneous regression of arrhythmias was occurring. Atropine (0.2 mg/kg i.v.) or methscopolamine (0.2 mg/kg i.v.) almost completely suppressed the ventricular arrhythmias which persisted in some animals on day 2. In animals with partially corrected tachyarrhythmias, atropine protected against aggravation of rhythm disturbances by norepinephrine and even more so against those induced by isoproterenol. The favorable effect of atropine seems to be mainly related to overdrive suppression. Atrial electrostimulation at a frequency slightly above that of the ventricular arrhythmias also normalized cardiac rhythm.