Biomedical subjects

V Matto

Publications and source records attributed to V Matto.

24 records · Page 2Linked to original sources

PubMed1997

The effect of drugs acting on CCK receptors and rat free exploration in the exploration box.

The effects of cholecystokinin (CCK) CCKA receptor antagonist devazepide (10 micrograms/kg and 1.0 mg/kg), CCKB receptor antagonist L 365260 (1.0 mg/kg), and CCKB receptor agonist CCK tetrapeptide (CCK-4, 75 micrograms/kg), and their concomitant administration with antidepressants desipramine (10 mg/kg) and citalopram (10 mg/kg) on rat exploratory behaviour were studied in the recently developed exploration box test. In addition, the effects of repeated administration of despiramine (10 mg/kg) and citalopram (10 mg/kg) were studied. After acute administration, CCK-4 decreased significantly the number of line crossings, rears, investigative approaches, and the time spent exploring. The time of latency and the number of entries into large arena were unchanged. Desipramine reduced all observed criterions of rat behaviour, but citalopram was ineffective. Devazepide (1.0 mg/kg) and L 365260 (1.0 mg/kg) had no effect on rat behaviour after acute or repeated administration. L 365260 (1.0 mg/kg) blocked the antiexploratory effect of CCK-4, whereas devazepide (10 micrograms/kg) did not. No interaction of CCK-4, devazepide, or L 365260 treatment with antidepressant treatment was found. Our results suggest that the administration of a CCKB agonist diminishes rat exploratory behaviour, but neither CCKA nor CCKB receptor blockade induces changes on rat exploratory behaviour in the free exploration paradigm.

Adrenergic Uptake Inhibitors↗

PubMed1997

Characterization of rat exploratory behavior using the exploration box test.

A method to measure various aspects of exploratory behavior was further characterized using standard pharmacological treatments known to induce anxiety, or anxiolysis, or locomotor activation. FG 7142, an anxiogenic beta-carboline, induced a dose-dependent reduction in the rat exploratory behavior. A single FG 7142 (20 mg/kg) treatment before behavioral testing had a carry-over effect on rats' behavioral performance on the two subsequent days. When FG 7142 (20 mg/kg) was administered during five consecutive days before behavioral testing, its anxiogenic-like effect first deepened, but waned off by the fifth session. Diazepam at the dose of 0.5 mg/kg had no effect of its own, but blocked the anxiogenic-like effect of FG 7142 (10 mg/kg) treatment. At a higher dose (1 mg/kg), diazepam treatment reduced exploratory behavior, but this effect was not carried over to the drug-free sessions on the subsequent day. Buspirone and gepirone (both 1 mg/kg), the 5-HT1A receptor agonists, had no effect. D-Amphetamine, a locomotion-enhancing drug which has anxiogenic-like properties in several tests of exploratory behavior, increased the activity of rats at the dose of 0.5 mg/kg, but at the dose of 1 mg/kg the only effect was a reduction in the number of rearings: this effect was not carried over to the subsequent retest. On the basis of the results described in this article and elsewhere, we suggest that this technique can be useful for separating a true anxiogenic drug from other compounds which influence exploratory activity.

Amphetamine↗

PubMed1996

The effects of cholecystokinin A and B receptor antagonists, devazepide and L 365260, on citalopram-induced decrease of exploratory behaviour in rat.

The present study has been divided into two sets. In the first set, the aim of the experiments was to investigate the dose-response effect of selective serotonin re-uptake inhibitor (SSRI) citalopram on rat exploratory behaviour in the elevated plus-maze. In the second set of experiments, the effect of cholecystokinin (CCK) CCKA and CCKB receptor antagonists, devazepide and L 365260, on citalopram-induced decrease of exploratory behaviour in the elevated plus-maze was studied. Citalopram (5 and 10 mg/kg) decreased the number of open and total arm entries, line crossings on open arms, and percentage of time spent exploring in open arm. Dose 15 mg/kg was without any effect on rat exploratory behaviour. Devazepide (0.01 and 1.0 mg/kg) failed to modify any of the citalopram-induced changes observed. L 365260 (1.0 mg/kg) reversed most of the effects of citalopram: the numbers of open and total arm entries, the number of line crossings, and the percentage of time spent exploring in open arms. L 365260 at dose level 0.01 mg/kg was ineffective. These results support the involvement of the CCKB receptor subtype in SSRI-induced anxiogenic-like effects in rodents.

Animals↗

PubMedDate not supplied

Additive effect of clonidine and fluoxetine on apomorphine-induced aggressive behavior in adult male Wistar rats.

BACKGROUND: Fluoxetine, a selective serotonin reuptake inhibitor, has been reported to be superior in its antiaggressive properties as compared with other antidepressants. The objective of the study was to investigate whether the effect of a minimal effective dose of fluoxetine could be potentiated by the alpha2-adrenergic agonist clonidine. METHODS: Vehicle (1.0 mL/kg), clonidine (0.1 mg/kg), fluoxetine (10 mg/kg), and their combination [clonidine (0.1 mg/kg) plus fluoxetine (10 mg/kg)] were injected into apomorphine-pretreated (1.0 mg/kg, once daily during 12 days) aggressive adult male Wistar rats. RESULTS: Repeated apomorphine treatment induced a gradual development of aggressive behavior. Combined clonidine and fluoxetine treatment attenuated the intensity of aggressive behavior, while these drugs alone had only a weak tendency toward reduction of aggression. Latency before the first attack was unchanged. CONCLUSIONS: Our experiments confirm that combined clonidine and fluoxetine treatment elicits an additive antiaggressive effect on apomorphine-induced aggressive behavior in rats.

Adrenergic alpha-Agonists↗

PubMedDate not supplied

Development of apomorphine-induced aggressive behavior: comparison of adult male and female Wistar rats.

The development of apomorphine-induced (1.0 mg/kg s.c. once daily) aggressive behavior of adult male and female Wistar rats obtained from the same breeder was studied in two consecutive sets. In male animals, repeated apomorphine treatment induced a gradual development of aggressive behavior as evidenced by the increased intensity of aggressiveness and shortened latency before the first attack toward the opponent. In female rats, only a weak tendency toward aggressiveness was found. In conclusion, the present study demonstrates gender differences in the development of the apomorphine-induced aggressive behavior and indicates that the female rats do not fill the validation criteria for use in this method.

Aggression↗

PubMedDate not supplied

Changes in [3H]citalopram binding in cerebral cortex after antidepressant treatment in monoamine-impaired rats.

The [3H]citalopram binding after three weeks vehicle, desipramine 10 mg/kg or citalopram 5 mg/kg treatment was studied in the cerebral cortex of normal, DSP-4-, and p-CPA-impaired rats. The DSP-4 50 mg/kg treatment decreased the affinity (Kd), but increased the maximal number of the apparent binding sites (Bmax) of the 5-hydroxytryptamine transporter (5-HTT). This effect was reversed by desipramine 10 mg/kg treatment. The p-CPA 350 mg/kg treatment decreased the Bmax value while the antidepressant treatment did not influence this parameter. In conclusion, our experiments demonstrate that the monoaminergic impairment induced by DSP-4 and p-CPA treatment evokes opposite changes in the 5-HTT binding characteristics and these changes are partially reversed by the chronic antidepressant treatment.

Animals↗