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Biomedical subjects

O Gandolfi

Publications and source records attributed to O Gandolfi.

67 records · Page 4Linked to original sources
PubMed1981

[Diphasic action of apomorphine on motility in the rat. II. Time aspects of the effect of a single dose].

The locomotor activity of rats subcutaneously treated with apomorphine HCl (300 microgram/kg, 30 sec before emmission into actometers) was evaluated every 60 sec for 1 hour. An inhibitory phase appeared in the first 6 min of recording in comparison to the more elevated values of the control group. From 18th to 44th min a more sustained activity was easily recognizable in treated rats in comparison to the decline of control values. The results were discussed by supposing that the first amounts of drug entering CNS stimulated pre-synaptic dopamine receptors and the full dose activated post-synaptic dopamine neurons. The study of time-course of a single dose of apomorphine could be a useful model for evaluating pre- and post-synaptic effects of antidopaminergic drugs.

Animals↗
PubMed1981

Reduction of ECS-induced retrograde amnesia of passive avoidance conditioning after 5,7-dihydroxytryptamine median raphe nucleus lesion in the rat.

5,7-Dihydroxytryptamine (5,7-DHT), median raphe nucleus (MRN)-lesioned and sham-lesioned rats were submitted to one-trial passive avoidance conditioning followed by electroconvulsive shock (ECS) or sham-ECS. On test session (24 h later) MRN-lesioned rats presented a longer conditioned response and, chiefly, a remarkable reduction of ECS-induced retrograde amnesia in comparison to sham-lesioned animals. This effect appeared unrelated to major changes in spontaneous behavior: on training session MRN-lesioned rats exhibited a faster stepping-down from the platform; their exploratory activity into a novel cage was characterized by a slightly higher initial response; moreover MRN lesion did not significantly effect pain threshold. A reduced brain 5-HT functional activity following MRN lesion was suggested by the study of the hyperactivity syndrome induced by tranylcypromine plus L-tryptophan. Lastly, MRN-lesioned rats showed a significantly lower brain 5-HT steady level without differing from the sham-lesioned ones with respect to turnover rate. The reduction of ECS-induced retrograde amnesia observed in 5,7-DHT, MRN-lesioned rats was considered as due to a lower synaptic availability of 5-HT at the time of ECS administration.

5,7-Dihydroxytryptamine↗
PubMed1979

Bromolysergide and methysergide protection against ECS-induced retrograde amnesia.

Bromolysergide (BOL 148) and methysergide (UML 491), 2 mg/kg intraperitoneally, and saline were administered to rats 45 min before one-trial passive-avoidance conditioning followed by electroconvulsive shock (ECS) or sham-ECS (ECS). On test session (24 h later), the groups treated with both BOL 148 and UML 491 exhibited a clear-cut retention in comparison to saline-ECS rats. On the other hand, all drugged groups, regardless of their submission to ECS, showed a little less pronounced consolidation than saline-ECS rats. The antiamnestic effect brought about by the two drugs was discussed in terms of receptor antagonism against ECS-released brain serotonin, whereas the lower passive-avoidance level observed in treated animals was considered in relation to a possible antipunishment effect of antiserotoninergic treatment.

Amnesia↗
PubMed1977

Recovery of amnestic effect of alpha-amanitin by post-training administration of d-amphetamine in the rat.

alpha-Amanitin, an inhibitor of RNA polymerase II, given intraventricularly 6 or 24 h before training, impaired consolidation of both passive and active avoidance responses in rats. Administration of d-amphetamine sulfate (0.5 mg/kg intraperitoneally) immediately after training produced a clear-cut antiamnestic effect in alpha-amanitin-injected rats without modifying consolidation in control animals. Examination of several parameters of conditioning enabled the authors to rule out an impairment in locomotor performance of alpha-amanitin-treated rats both in training and in test sessions. The amnestic effect of alpha-amanitin and recovery by means of d-amphetamine were discussed in relation to RNA synthesis inhibition and a possible restoring effect of d-amphetamine upon alpha-amanitin-induced decrease of brain RNA content.

Amanitins↗
PubMed1976

Effect of single and repeated administration of sulpiride on the restraint ulcer in the rat.

Preventive activity of N-ethyl-2(2-methoxy-5-sulfamido-benzamidomethyl)-pyrrolidine (sulpiride, Dobren) upon restraint ulcer has been studied using two strains of rats (Wistar and Sprague-Dawley) treated with single or repeated administration of 5, 10, 20, 40 mg/kg i.p. of the drug. Wistar strain was shown to be less sensitive to the ulcerogenic procedure and a significant preventive effect of sulpiride occurred only at the dose of 10 mg/kg i.p. In the Sprague-Dawley strain a preventive effect was present not only at this dose but also at the dose of 20 mg/kg i.p. and 5 mg/kg i.p., the latter dose giving the greatest effect. Animals receiving the dose of 40 mg/kg i.p. did not differ significantly from the control in both strains. Results are discussed in relation to possible changes of the cerebral mono-amine turnover during the establishment of stress ulcer, particularly in terms of restoration of the balance between dopamine (DA) and norepinephrine (NE) neuronal activity.

Animals↗
PubMed1975

Thin-layer chromatography of sulphonamides on silica gel G and polyamide layers by means of a polar mobile phase.

A thin-layer chromatographic system based on polyamide or silica gel G layers and an aqueous mobile phase was used for the separation of a series of sulphonamides. A linear relationship between RM values on polyamide layers and the acetone concentration in the mobile phase allowed the calculation of extrapolated RM values. The influence of the nature of the stationary phase on the migration of compounds is discussed.

Acetone↗
PubMed1975

Rm values of phenols. Their relationship with log P values and activity.

The experimental Rm values for a series of phenols were obtained by a reversed-phase TLC system. The extrapolation from a range of linear relationship between experimental Rm values and acetone concentration provided a set of extrapolated Rm values. This were used for studying the relationship between structure and activity in vitro and in vivo. The possibility to obtain by means of the extrapolation technique the Rm values in a standard system for serveral series of chemotherapeutic agents is pointed out.

Animals↗
PubMed1975

Rm values of steroids as an expression of their lipophilic character in structure-activity studies.

The chromatographic Rm values of three series of steroids were determined by means of a reversed-phase system. The Rm values at 45% acetone in the mobile phase were shown to be correlated with the partition coefficients in an ether-water system. However, an almost equally good correlation was found when using extrapolated Rm values. The extrapolation technique could provide a standard system. The relationship between biological data and Rm values pointed out the important role of the lipophilic character in regulating the activity of steroids. In particular, the dependence of protein binding absorption and biotransformation on lipophilic character might strongly influence the availability of steroids at the site of action.

Animals↗