1,056 research outputs found
Effects of )eticlopride and 7-OH-DPAT on the tail-suspension test in mice
No full textThe dopamine (DA) D-2/D-3 antagonist (-)eticlopride (0.02, 0.05 and 0.1 mg/kg), dose-dependently increased immobility in the mouse tail-suspension test. Chronic treatment with the same compound (0.05, 0.1 mg/kg, x 14 days) produced a different effect, decreasing immobility when animals were tested 24 h after the last injection. The DA D-3 agonist, 7-OH-DPAT, acutely administered before the same test, behaved biphasically, increasing and decreasing mice immobility at low (0.05 and 0.1mg/kg) and high (1 and 2 mg/kg) doses, respectively. Chronically administered 7-OH-DPAT reduced the immobility time at 2 mg/kg but not at 0.1mg/kg. These effects, coupled with measurements of locomotor activity and evaluation of mice behaviour in different conditions, are discussed in the light of putative DA involvement in depressive states and are considered as predicting antidepressant potential
Hyperphagic effects of the α2 adrenoceptor antagonists idazoxan and yohimbine in the x-maze feeding test
No full textBEHAVIOURAL ASSESSMENT IN RATS OF THE ANTIPSYCHOTIC POTENTIAL OF THE POTENT DOPAMINE D2 RECEPTOR ANTAGONIST, (-) ETICLOPRIDE
No full textThe effects of the selective D-2 DA receptor antagonist, (-)eticlopride, a drug belonging to the benzamide class, were investigated on the D-2 DA agonist SND 919- and CQP 201-403-induced stereotyped behaviour and on CQP 201-403-induced shaking, in rats, and on isolation-induced aggression, in mice. (-)Eticlopride was also tested over a wide dose range (5-1200 mu g kg(-1), s.c.) for sedative and cataleptic activity, in rats, For comparison, some experiments were performed with (-)sulpiride (10 and 40 mg kg(-1), s.c.) The data obtained show that (-)eticlopride differs from (-)sulpiride and potentially modifies animal behaviour, whether spontaneous or induced; moreover, they suggest a potential clinical use for this neuroleptic in the management of psychotic states
THE SELECTIVE D-2-DOPAMINE-RECEPTOR ANTAGONIST ETICLOPRIDE COUNTERACTS THE EJACULATIO-PRAECOX INDUCED BY THE SELECTIVE D-2-DOPAMINE AGONIST SND-919 IN THE RAT
No full textThe selective D-2 antagonist eticlopride, at a dose (0.01 mg/kg, s.c.) that fails to modify the normal behavior of rats, significantly reversed all the behavioral effects exerted by the selective D-2 agonist SND 919 (0.1 mg/kg, i.p.), namely, the stimulation of stretching-yawning, penile erection and sedation and the inhibition of grooming. In the copulatory test, eticlopride at the same dose did not affect animal sexual behavior but potently counteracted the reduction in mount and intromission frequency and latency to ejaculation induced by SND 919 at 0.1 mg/kg, a behavioral pattern which might possibly be proposed as an animal model for human ejaculatio praecox
INABILITY OF )DEPRENYL TO MODIFY COPULATORY PERFORMANCE IN THE MALE-RAT, WHETHER OR NOT STIMULATED BY THE SELECTIVE D-2 DOPAMINE AGONIST SND-919
No full textINABILITY OF )DEPRENYL TO MODIFY COPULATORY PERFORMANCE IN THE MALE-RAT, WHETHER OR NOT STIMULATED BY THE SELECTIVE D-2 DOPAMINE AGONIST SND-91
BEHAVIOURAL EFFECTS OF THE DOPAMINE D3 RECEPTOR AGONIST, 7-OH-DPAT IN RATS.
No full textThe putative selective dopamine (DA) D3 receptor agonist, 7-OH-DPAT (25-4000 micrograms kg-1), enhanced stretching-yawning and penile erection in male rats, besides respectively increasing and decreasing sedation at low (25-200 micrograms kg-1) and high (1600 and 4000 micrograms kg-1) doses and inducing stereotypy from 800 micrograms kg-1 upwards. The DA D2 antagonist, (-) eticlopride (10 and 20 micrograms kg-1), antagonized stretching-yawning and penile erection induced by a low dose of 7-OH-DPAT (50 micrograms kg-1) but not those produced by high doses (1600 and 4000 micrograms kg-1), when stereotyped behaviour, on the other hand, was potently inhibited. Comparative experiments performed with the DA agonist SND 919 gave similar results
Influence of eticlopride on cocaine- and DA D-2 agonist-induced behavioral effects in rats
No full textThe influence of the DA D-2 antagonist (-) eticlopride on cocaine- and DA D-2 agonist-induced behavioral effects was investigated by means of two series of experiments, in rats. In the first 10-day series, coadministration of (-) eticlopride (10 and 50 mu g/kg, SC) always potently inhibited cocaine (15 mg/kg, IP)-induced hypermotility but did not modify the penile erection (PE)-enhancement produced by the drug at the first injection; it actually counteracted the inhibitory effect of subchronic cocaine on PE. In the second series, (-) eticlopride, at the same doses, antagonized PE elicited by various DA D-2 agonists at nonstereotyping doses; when, along with PE, stereotyped behavior was induced, only the latter was inhibited by (-) eticlopride, which even increased PE
INVOLVEMENT OF DOPAMINE D2 RECEPTORS IN THE EFFECT OF COCAINE ON SEXUAL BEHAVIOUR AND STRETCHING-YAWNING OF MALE RATS.
No full textThe effect of cocaine (7.5, 15 and 30 mg/kg) administered in acute or subchronic mode, on the mating behaviour of sexually active male rats varied in a dose- and mode-dependent manner. Regardless of mode of treatment, 30 mg/kg markedly impaired the rats ́ copulatory ability and impairment continued for a week after suspension of subchronic treatment. An acute dose of 15 mg/kg reduced intromission frequency, while in subchronic mode it also reduced ejaculation latency. Mount frequency was increased by 7.5 and 15 mg/kg, but only on first injection. In the case of sexually-naive male rats, acute administration of cocaine (3-30 mg/kg) stimulated penile erections at 7.5 mg/kg and motor hyperactivity at all doses. (-) Eticlopride (0.025 and 0.05 mg/kg), a DA D-2 antagonist, counteracted cocaine-induced motor hyperactivity but not penile erection, which it enhanced. (-)Eticlopride at the same doses also antagonized cocaine potentiation of lisuride (0.2 mg/kg)-induced behavioural effects. When male rats treated with subchronic cocaine (15 mg/kg) were injected with the DA D-2 agonist SND 919 (0.1 mg/kg), they displayed a more marked stretching-yawning behaviour than control animals receiving SND 919 at the same dose. The involvement of DA D-2 receptors in cocaine-induced effects is suggested
Differential behavioral response to dopamine D-2 agonists by sexually naive, sexually active, and sexually inactive male rats
No full textThis study was performed with male rats categorized as sexually naive (SN), sexually active (SA), or sexually inactive (SI). In a first experiment the effects of the dopamine (DA) D-2 agonist SND 919 (0.05, 1, and 10 mg/kg) on the copulatory behavior of SN, SA, and SI rats were assessed. In a second experiment the DA D-2 agonist B-HT 920 (0.2 mg/kg) was used, and examination was limited to SN and SA rats. The effects exerted on stretching-yawning, penile erection, and sedation by the same compounds at the same doses in these three rat categories were also investigated. The main findings were that SND 919 and B-HT 920 facilitated ejaculation in SA rats, and that the rats that were different as regards level of sexual activity Exhibited different behavioral responses to the two DA agonists
HU 210: A potent tool for investigations of the cannabinoid system
No full textThe synthetic compound HU 210 displays a multiplicity of biochemical, pharmacological, and behavioral effects, most of which have been demonstrated to be dependent on a selective agonistic activity at CB1 and CB2 cannabinoid receptors and to involve the main neurotransmitter systems. Results obtained in various studies suggest a potential clinical application of this highly potent drug (e.g., as antipyretic, antiinflammatory, analgesic, antiemetic, and antipsychotic agent) as well as its usefulness in research aimed to develop a better understanding of the involvement of the endogenous cannabinoid system in a number of physiopathological functions
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