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Biomedical subjects

J Maj

Publications and source records attributed to J Maj.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Antagonistic effect of cyproheptadine on neuroleptic-induced catalepsy.

The influence of cyproheptadine on the neuroleptic-catalepsy in rats was studied. Cyproheptadine antagonized dose-dependently the catalepsy induced by spiroperidol, pimozide, fluphenazine and reserpine. The anticataleptic effect of two antiparkinsonian drugs, L-DOPA or amantadine was potentiated by cyproheptadine.

Amantadine↗
PubMedDate not supplied

Antidepressant activity of S-adenosyl-L-methionine in mice and rats.

S-Adenosyl-L-methionine (SAM), main methyl donor, was tested in mice and rats in several models which are predictive of possible antidepressant activity. In the forced swimming test in rats the effect of SAM was compared with that of the tricyclic antidepressant amitriptyline. SAM decreased dose-dependently immobility time in the forced swimming test in mice and rats, these effects being antagonized by haloperidol and prazosin (the latter only in rats). Locomotor or exploratory activity in mice and rats was not increased by SAM. D-Amphetamine-induced locomotor hyper-activity in rats was increased by repeated (14 days, twice daily) treatment with SAM. Behavioural stimulation induced by D-amphetamine or L-dopa (given with benserazide) in mice was not changed by a single dose of SAM. The drug reduced hypothermia induced by apomorphine in mice. Hypothermia induced by reserpine or clonidine in mice was not antagonized. SAM increased the amplitude of the acoustic startle reflex. The above results indicate that the psychopharmacological profile of SAM resembles that of antidepressants in only some tests. The mechanism by which SAM produces its antidepressant effect needs further investigation.

Amphetamine↗
PubMedDate not supplied

Pharmacological profile of milnacipran, a new antidepressant, given acutely.

Pharmacological effects of acute treatment with milnacipran (MIL), a clinically active antidepressant (a noradrenaline [NA] and 5-hydroxytryptamine [5-HT] reuptake inhibitor without any affinity for neurotransmitter receptors) were studied in mice and rats. MIL inhibited the reserpine- or apomorphine-induced hypothermia in mice and enhanced the L-5-hydroxytryptophan-induced head twitches in rats. It reduced the immobility time in Porsolt's test in mice and rats, but either did not change the locomotor activity (mice) or decreased it (rats). MIL changed neither the clonidine-induced aggressiveness in mice nor the behavioral syndrome induced by oxotremorine in rats. The obtained results indicate that MIL, given acutely, shows a pharmacological profile similar to that of tricyclic NA and 5-HT reuptake inhibitors. In contrast to the antidepressants mentioned above, MIL does not exhibit an alpha1-adrenolytic or cholinolytic activity (in vivo tests).

5-Hydroxytryptophan↗
PubMedDate not supplied

Synergistic effect of pramipexole and sertraline in the forced swimming test.

The authors studied the effect of sertraline, one of selective serotonin reuptake inhibitors (SSRIs), and pramipexole, administered jointly, to male Wistar rats in the forced swimming test. Both those drugs were injected three times (24, 5 and 1 h before the test): sertraline at doses of 5 and 10 mg/kg ip, pramipexole at doses of 0.05, 0.1 and 0.3 mg/kg sc. Sertraline given separately was inactive in the test used. Pramipexole reduced the immobility time only at a dose of 0.3 mg/kg. Joint administation of both those drugs distinctly shorted the immobility time, that effect.being particularly strong at pramipexole, 0.3 mg/kg, and sertraline, 5 or 10 mg/kg. The obtained results indicate that sertraline--like the previously tested citalopram and fluoxetine--shows a synergistic effect when given with pramipexole in the forced swimming test.

Animals↗
PubMedDate not supplied

Pharmacological profile of reboxetine, a representative of new class of antidepressant drugs, selective noradrenaline reuptake inhibitor (NARI), given acutely.

Pharmacological effects of acute treatment with reboxetine (REB), a clinically active antidepressant (a noradrenaline reuptake inhibitor without any affinity for neurotransmitter receptors), were studied in mice and rats. REB inhibited the reserpine- or apomorphine-induced hypothermia in mice. It reduced the immobility time in Porsolt's test in mice and rats, but it did not change the locomotor activity in mice and rats. REB changed neither the clonidine-induced aggressiveness in mice nor the behavioral syndrome induced by oxotremorine in rats. The obtained results indicate that REB, given acutely, shows a pharmacological profile similar to that of tricyclic or tetracyclic noradrenaline reuptake inhibitors. In contrast to the antidepressants mentioned above, REB does not exhibit an alpha1-adrenolytic or cholinolytic activity (in vivo tests).

Adrenergic Uptake Inhibitors↗
PubMedDate not supplied

Effect of repeated treatment with milnacipran on the central dopaminergic system.

Milnacipran (MIL) is a representative of a new class of antidepressants (SNRIs) which inhibit the reuptake of serotonin and noradrenaline, but, in contrast to tricyclics, show no affinity for neurotransmitters receptors. The present study was aimed at determining whether repeated MIL administration (given at doses of 10 or 30 mg/kg, twice daily for 14 days) induced the adaptive changes in the dopaminergic system similar to those reported by us earlier for tricyclic antidepressants. The obtained results showed that MIL administered repeatedly did not change the responsiveness of dopamine D1 receptors since it did not change the SKF 38393-induced grooming. Repeated MIL treatment increased the hyperlocomotion induced by D-amphetamine and 7-OH-DPAT, but did not affect the D-amphetamine and apomorphine stereotypies. The binding parameters (Bmax and Kd) to dopamine D1 and D2 receptors in the limbic forebrain were not affected by repeated MIL treatment when [3H]SCH 23390 and [3H]spiperone, respectively, were used as ligands. On the other hand, the increased density of dopamine D2 receptors (Bmax) was observed in the striatum after repeated treatment with MIL. MIL administered acutely or repeatedly did not change the binding of [3H]7-OH-DPAT to dopamine D3 receptors in the islands of Calleja and the shell region of the nucleus accumbens septi. The above results indicate that repeated MIL administration induces the adaptive changes in the dopaminergic system, especially it enhances the functional responsiveness of dopamine D2 and D3 receptors. However, the question whether this increased functional responsiveness is important for the clinical antidepressant efficacy, remains open.

Amphetamine↗
PubMedDate not supplied

Three new derivatives of 3-amino-1,2-propanediol; their spectral properties and biological evaluation.

Three new derivatives of 3-amino-1,2-propanediol have been synthesized. Full assignments of signals in their 1H- and 13C-NMR spectra are given. The influence of these compounds on the cardiovascular system in the anaesthetized rat was examined. In contrast to CGP 12177 which induced a strong increase in heart rate and a slight increase in blood pressure, compounds 1, 2 and 3 x HCl at doses up to 1 micromol/kg and compound 3 at doses of 0.01 and 0.1 micromol/kg did not change the cardiovascular parameters. The highest dose of compound 3-1 micromol/kg caused a very short-lasting decrease in heart rate (by 14%) and in blood pressure (by 25%).

Animals↗
PubMedDate not supplied

Locomotor hypoactivity and motor disturbances--behavioral effects induced by intracerebellar microinjections of dopaminergic DA-D2/D3 receptor agonists.

In the light of recent findings, DA-D3 dopamine receptors with an unclear physiological function are present in the cerebellar cortex. Our preliminary results seem to indicate that bilateral injection of 7-OH-DPAT, a DA-D2/D3 receptor agonist (1 and 10 microg/0.5 microl), to lobule 9/10 of rat cerebellar cortex reduces spontaneous locomotor activity (hypolocomotor effects) and induces balance and motor coordination disturbances, respectively. Similar effects can be observed in the case of analogous microinjection of the DA-D3/D2 agonist pramipexole. In earlier studies, peripheral (ip) injection of nafadotride (0.6 mg/kg), a D3 receptor antagonist, neither affected per se spontaneous motor activity, nor modified the above described effects of 7-OH-DPAT. Participation of cerebellar DA-D3 and DA-D2 receptors in hypolocomotor effects, as well as putative participation of other receptors in the generation of motor disturbances, has been discussed.

Animals↗
PubMedDate not supplied

The effect of CGP 37849 and CGP 39551, competitive NMDA receptor antagonists, in the forced swimming test.

The present study examined the effects of CGP 37849 and CGP 39551, competitive NMDA receptor antagonists, in the forced swimming test in rats and mice. Administered in a single dose or three times both examined compounds reduced the immobility time in rats. Active doses used in that test either did not change the locomotor activity or decreased it. A similar effect in both tests was shown by active (R)-enantiomers CGP 40116 and CGP 43487. Reduction of the immobility time induced by CGP 37849 and CGP 39551 in the forced swimming test in rats was antagonized by haloperidol and (+/-)-sulpiride, but not by SCH 23390 or prazosin. CGP 37849, but not CGP 39551, also reduced the immobility time in the forced swimming test in mice. The results obtained indicate that CGP 37849 and CGP 39551 induce an antidepressant-like effect in the forced swimming test, probably via an indirect dopamine activation resulting from blockade of NMDA receptors.

2-Amino-5-phosphonovalerate↗
PubMedDate not supplied

The effects of combined treatment with MK-801 and antidepressant drugs in the forced swimming test in rats.

We found previously that combined administration of imipramine, citalopram and, to a lesser extent, mianserin with MK-801, a non-competitive NMDA receptor antagonist, reduced the immobility time in the forced swimming test in rats more potently than administration of the antidepressant or MK-801 alone. In present paper we examined the effect of other antidepressants in this model. (+)-Oxaprotiline and (-)-oxaprotiline which, when given alone, showed a weak positive effect, increased the action of MK-801. Fluoxetine, inactive when given alone, markedly increased the effect of MK-801. Moreover, the positive effect after combined treatment was found in the experiments in which antidepressants and MK-801 given separately were inactive. A reduction in the immobility time was also observed in those experimental paradigms in which the locomotor activity was not increased. The effects of combined treatment with the antidepressants studied + MK-801 were antagonized by haloperidol, but not by prazosin. The obtained results indicate that mainly a dopamine mechanism seems to be involved in the synergistic action of MK-801 and the antidepressants in the forced swimming test.

Animals↗