Biomedical subjects

J Maj

Publications and source records attributed to J Maj.

At least 37 records · Page 2Linked to original sources

PubMed1996

Antidepressant drugs given repeatedly change the binding of the dopamine D2 receptor agonist, [3H]N-0437, to dopamine D2 receptors in the rat brain.

The effects of antidepressants given in a single dose or repeatedly (10 mg/kg p.o., twice daily, 14 days) on binding to dopamine D2 receptors in the striatum and limbic forebrain of Wistar male rats were studied. [3H]N-0437, (2-(N[2,3(n)-3H]propyl-N-(2-thiofuranyl)-2'-ethylamino) -5-hydroxy-1,2,3,4-tetrahydronaphthalene), a dopamine D2 receptor agonist, was used as a ligand. Already a single dose of imipramine and fluoxetine caused a statistically significant decrease in the affinity of the ligand for dopamine D2 receptors in the striatum, but only at 72 h after drug administration. Also at 72 h after the single dose of mianserin a significant increase in the density of dopamine D2 receptors was observed. Repeated imipramine, amitriptyline and mianserin increased the affinity for dopamine D2 receptors in the striatum and in the limbic forebrain. Repeated fluoxetine increased that affinity in the striatum, but decreased it in the limbic forebrain. The density of dopamine D2 receptors was increased by the repeated administration of the antidepressants studied in the limbic forebrain, but was not changed in the striatum. The results obtained in the present study are in good agreement with the previously reported enhancement of behavioural responsiveness to dopamine and dopamine stimulants (dopamine D2 up-regulation) evoked by repeated treatment with antidepressants.

Amitriptyline↗

PubMed1996

Roxindole, a potential antidepressant. I. Effect on the dopamine system.

Roxindole (EMD 49980, 5-hydroxy-3-[4-(4-phenyl-1,2,3,6-tetrahydropyridyl(1))-butyl(1)]-indole mesylate), a selective dopamine autoreceptor agonist and a potential antipsychotic drug, shows a clinical antidepressant efficacy. The present paper examined the neuropharmacological profile of roxindole in rats (male Wistar) and mice (male Albino Swiss) in respect of its influence on dopamine system. Used in low doses, roxindole decreased the locomotor activity, but in higher ones it did not induce a locomotor hyperactivity or stereotypy. It antagonized the amphetamine-induced hyperlocomotion, the amphetamine- or apomorphine-induced stereotypy, apomorphine climbing behaviour and reserpine-induced akinesia. The quinpirole-induced hyperlocomotion was inhibited by roxindole. When given alone, the drug in question, did not induce the catalepsy, but antagonized the catalepsy induced by haloperidol, spiperone and fluphenazine. The immobility time in the forced swimming test was reduced. Like typical antidepressants, roxindole given repeatedly (twice daily, 14 days) increased the hyperlocomotion induced by D-amphetamine. The results described above indicate that roxindole may have an antidepressant and antiparkinsonian activity and should be devoid of extrapyramidal side-effects.

Amphetamine↗

PubMed1996

The synergistic effect of fluoxetine on the locomotor hyperactivity induced by MK-801, a non-competitive NMDA receptor antagonist.

It was found previously that the MK-801 (an uncompetitive NMDA receptor antagonist)-induced locomotor hyperactivity in rats was potently increased by antidepressant drugs. The present paper analysed the locomotor hyperactivity induced by combined treatment with fluoxetine + MK-801 in male Wistar rats. The MK-801 hyperactivity was increased by citalopram (the latter effect was prevented by zacopride and ketanserin), sertraline, p-chloramphetamine, 8-OH-DPAT and TFMPP. The hyperlocomotion caused by fluoxetine + MK-801 was antagonized by tropisetron and zacopride and, to a lesser extent, by ketanserin, ritanserin and NAN-190, but not by WAY 100135, pindolol, metergoline or mianserin. Sulpiride and clozapine were able to inhibit the fluoxetine + MK-801 hyperlocomotion. The hyperlocomotion induced by D-amphetamine or apomorphine was not modified by fluoxetine or citalopram. Fluoxetine increased the release of dopamine (measured by a microdialysis method) in the striatum, induced by MK-801. The obtained results indicate that fluoxetine increases the MK-801-induced locomotor hyperactivity via activation of 5-HT3 receptors and, to a lesser degree, 5-HT2 ones.

Animals↗

PubMed1996

The effects of paroxetine given repeatedly on the 5-HT receptor subpopulations in the rat brain.

Effects of paroxetine (10 mg/kg PO, twice daily, 14 days) on 5-HT receptor subpopulations in the brain were evaluated pharmacologically, electrophysiologically and biochemically in male Wistar rats. Imipramine was used for comparison. Repeated paroxetine antagonized the 8-OH-DPAT-induced behavioural syndrome (a 5-HT1A effect); imipramine showed similar, yet weaker, activity. The 5-HT-or 8-OH-DPAT-induced inhibition of population spikes in hippocampal slices was increased by both those repeated antidepressants. Repeated (or acute) paroxetine decreased the density of and increased the affinity for 5-HT1A receptors ([3H]-8-OH-DPAT used as ligand) in the hippocampus, while imipramine induced opposite effects. m-Chlorophenyl piperazine (m-CPP)-evoked exploratory hypoactivity, a 5-HT2C effect, was reduced by repeated paroxetine, but not by imipramine. Either of the antidepressants given repeatedly antagonized TFMPP-induced hyperthermia (another putative 5-HT2C effect). 5-HTP-induced head twitches (a 5-HT2A effect) were inhibited by repeated paroxetine or imipramine. Either antidepressant given repeatedly decreased the density of 5-HT2A receptors ([3H]-ketanserin as a ligand) in the brain cortex, but did not change their affinity. The present results indicate that paroxetine given repeatedly induces secondary changes in 5-HT2 receptors, which lead to reduction of the 5-HT2 neurotransmission (reduced responsiveness of 5-HT2 postsynaptic receptors). The consequences of the secondary changes in 5-HT1A receptors, found here still await clarification.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1996

[The reason for the removal of springing foreign bodies in the esophagus].

The author described a group of 28 prisoners with the springing foreign bodies. In this group were follow foreign bodies diagnosed: so called anchors, crabs and crossbreeds. Three prisoners no consent to esophagoscopy and two, with symptoms of thoracic esophageal perforation, were treated in Thorax Surgery Department. 21 foreign bodies were removal esophagoscopical and 2 remaining were extracted by the lateral pharyngotomy. Own observations have confirmed the effectiveness of esophagoscopy in removal of the springing foreign bodies in the esophagus.

Endoscopy↗

PubMed1994

Pharmacological action of zotepine and other antipsychotics on central 5-hydroxytryptamine receptor subtypes.

The effect of the atypical neuroleptic zotepine (CAS 26615-21-4), in comparison with clozapine, risperidone and haloperidol, on the responsiveness of different 5-hydroxytryptamine (5-HT1) receptor subtypes to their agonists was examined in rats and mice. The above antipsychotics were investigated in the following behavioural tests: 8-OH-DPAT (8-hydroxy-dipropylaminotetralin)-induced behavioural syndrome in rats, mCPP (mchlorophenylpiperazine)-induced hypothermia in mice and mCPP-induced hypoactivity measured in the open field in rats. Zotepine, clozapine and haloperidol did not affect the behavioural syndrome induced by 8-OH-DPAT (the selective agonist of 5-HT1A, receptor), only risperidone (used in higher doses) attenuated the effect of 8-OH-DPAT. The mCPP-induced hypothermia in mice (a 5-HT1B effect) was affected by neither zotepine nor clozapine, risperidone and haloperidol, all of them used in low doses which did not influence per se the body temperature of mice. All the tested antipsychotics given at high doses induced hypothermia in control mice; at the same time, zotepine, clozapine and risperidone attenuated the hypothermic effect of mCPP. mCPP decreases the exploratory activity of rats, this effect being considered to be mediated by 5-HT1C receptors. The tested antipsychotics, used in low doses, influenced neither the exploratory activity nor the hypoactivity induced by mCPP. When used at higher doses, they induced hypoactivity in control rats; the hypoactivity after joint administration of zotepine, risperidone or haloperidol and mCPP was significantly greater than after mCPP alone, whereas clozapine slightly attenuated the effect of mCPP.(ABSTRACT TRUNCATED AT 250 WORDS)

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1994

[Multifocal status and malignant transformation of pleomorphic adenoma].

A rare case of multifocal and malignant pleomorphic adenoma in 60-years--old male is presented. Its diagnosis was made on the basis of the case--history, clinical picture and biopsy. The clinical course and therapeutic tactics are briefly described. The conclusion of prognosis in this pleomorphic adenoma form is difficult.

Adenoma, Pleomorphic↗

PubMed1994

[A case of Dieffenbachia poisoning].

A case is presented of poisoning with, even more frequently cultivated in flats, Dieffenbachia. The mechanism of toxic effect of the juice of this plant is discussed. Prophylactic and therapeutic guidelines are presented.

Humans↗

PubMed1993

Some central effects of CGP 37849 and CGP 39551, the competitive NMDA receptor antagonists: potential antiparkinsonian activity.

Two new competitive NMDA receptor antagonists with oral activity CGP 37849 (D,L-E-amino-methyl-phosphono-3-pentenoic acid) and its ethyl ester CGP 39551 were studied in rats. CGP 37849 did not change the locomotor activity or increased it. The hyperactivity induced by CGP 37849 was antagonized by haloperidol but not idazoxan or prazosin. CGP 39551 decreased the locomotor activity. The studied compounds did not increase the locomotion in monoamine-depleted (pretreated with reserpine and alpha-methyl-p-tyrosine) rats. Clonidine induced antiakinetic effect in monoamine-depleted rats. This effect was more pronounced after joint administration of clonidine and CGP 37849 or CGP 39551. The locomotor hyperactivity induced by joint administration of CGP 37849 and clonidine was inhibited by haloperidol but not prazosin or idazoxan. CGP 37849 but not CGP 39551 also enhanced antiakinetic effect of L-DOPA (given together with benserazide) in monoamine-depleted rats. CGP 37849 antagonized the spiperone- and fluphenazine-induced catalepsy; CGP 39551 had considerably weaker antagonistic effect. The reserpine-induced catalepsy was attenuated by CGP 37849. MK-801, a non-competitive NMDA antagonist inhibited spiperone- but not reserpine-induced catalepsy. The obtained results indicate that CGP 37849 administered alone or in combination with L-DOPA or clonidine may be a potential antiparkinsonian drug.

2-Amino-5-phosphonovalerate↗

PubMed1993

Effects of fluoxetine given chronically on the responsiveness of 5-HT receptor subpopulations to their agonists.

The effect of chronic treatment (5 and 10 mg/kg i.p., twice daily, 14 days) with fluoxetine (FLU), an antidepressant drug which selectively inhibits the reuptake of 5-hydroxytryptamine (5-HT), on the responsiveness of 5-HT receptor subpopulations to their agonists in rats and mice was examined. FLU had no effect on the hypothermia (in mice) and the behavioural syndrome (in rats) induced by 8-OH-DPAT (a 5-HT1A agonist). The m-CPP-induced hypothermia in mice (a 5-HT1B effect) was increased by FLU given chronically. FLU in a single dose decreased that effect. FLU given chronically attenuated the m-CPP-induced hypoactivity in rats (a 5-HT1C effect). The effects mediated by 5-HT2 receptors (L-5-HTP-induced head twitches in mice; fenfluramine-, m-CPP- and TFMPP-induced hyperthermias in rats) were reduced by chronic FLU. The above results indicate that FLU given chronically has no effect on the responsiveness of 5-HT1A receptors, increases the responsiveness of 5-HT1B receptors and decreases those of 5-HT1C and 5-HT2 receptors.

5-Hydroxytryptophan↗

PubMed1993

Pharmacological effects of zotepine and other antipsychotics on the central 5-HT2 receptors.

The effects of the atypical neuroleptic zotepine in comparison with clozapine, risperidone and haloperidol were examined in tests related to the central 5-HT2 activity. Zotepine, as well as clozapine and risperidone, were very potent inhibitors of the 5-HTP-induced head twitches (the behavior mediated by 5-HT2 receptors) in mice, with rank order of potency risperidone > zotepine > clozapine; haloperidol used in high doses only slightly reduced the effect of 5-HTP. Zotepine, clozapine, risperidone and haloperidol antagonized the stimulatory effects of mCPP on the hind limb flexor reflex in spinal rats. As the mCPP-induced stimulation is considered to be mediated by 5-HT2 receptors, the above results provide further evidence for the 5-HT2 antagonistic activity of the drugs studied. Te rank order of potency in that test was the same as in the 5-HTP-induced head twitches (risperidone > zotepine > clozapine). The effect of haloperidol was somewhat unspecific, since its active doses were very high. In the model of hind limb flexor reflex of spinal rats, the anti-alpha 2-adrenergic effect was also tested. Clonidine-induced stimulation of the hind limb flexor reflex (an alpha 2-adrenergic effect) was antagonized by zotepine, clozapine, risperidone and haloperidol. It may be concluded that zotepine, clozapine and risperidone show an alpha 2-adrenergic antagonistic activity (order of potency: zotepine = risperidone > clozapine). The effect of haloperidol may be considered unspecific, since it is observed at high (cataleptic) doses only. In conclusion, it appears that zotepine, as well as clozapine and risperidone, are strong 5-HT2 antagonists, while haloperidol is not.

Animals↗

PubMed1993

[On early diagnosis of nasopharyngeal cavity neoplasms].

A group of 58 patients with nasopharyngeal malignancies are described and subjected to statistical analysis. The programme of diagnostic management and results of its realization are presented. The following was subjected to analysis: age and sex of the patients, complaints reported by them, and the clinical progression of the disease determined by physical and X-ray examinations. Taking into account the U.I.C.C. directives, the histological structure of the tumours was assessed as well as the incidence and character of metastases in regional lymph nodes. In the discussion attention is paid to the causes of delayed diagnosis of these tumours, while in the conclusions the factors are presented whose observation exerts a beneficial effect on further fates of patients.

Adolescent↗

PubMed1993

[Calcifying epithelial odontogenic tumor].

A rare case of calcifying epithelial odontogenic tumor (Pindborg's tumor) is presented. This tumor was situated in the left nasal cavity. The mucosa overlying the tumor was intact. Its presenting clinical symptoms were hemilateral gradually increased bulging floor of the nase and magnifying nasal stenosis. The tumor was generally radiolucent but contained fully developed embedded tooth. With the patient under local anesthesia the tumor was total enucleated without difficulty. Histologically the lesion presented the typical features of a calcifying epithelial odontogenic tumor. Two years after the operation the patient was without recurrence.

Adult↗

PubMed1993

[The exceptional way of spreading of the parapharyngeal space abscess].

The authors described the exceptional way of spreading of the parapharyngeal space abscess. Succession of this process were hypostatic abscesses of the lumbo-sacral region. Incision and drainage parapharyngeal abscess and as well hypostatic abscesses pointed out the usefulness in treatment.

Abscess↗

PubMed1992

Effects of sertraline and citalopram given repeatedly on the responsiveness of 5-HT receptor subpopulations.

The effect of repeated treatment (5 and 10 mg/kg, po, twice daily, 14 days) with sertraline and citalopram (antidepressants which selectively inhibit the reuptake of 5-hydroxytryptamine (5-HT)) on the responsiveness of different 5-HT receptors to their agonists, was examined in rats and mice. Sertraline and citalopram (both at a dose 5 and 10 mg/kg) antagonized (the first one more potently) the hypothermia induced in mice by 8-OH-DPAT (a 5-HT1A agonist), but not the behavioural syndrome induced in rats by this substance. The m-chlorophenylpiperazine-induced hypothermia in mice (a 5-HT1B effect) was increased by sertraline and citalopram (only in a dose of 10 mg/kg). Both antidepressants, given repeatedly (as well acutely) attenuated exploratory hypoactivity induced in rats by m-chlorophenylpiperazine (a 5-HT1C effect). L-5-HTP-induced head twitches in mice (5-HT2 effect) were antagonized dose-dependently by both repeated sertraline and citalopram. Both antidepressants (citalopram only in higher dose) reduced the fenfluramine-induced hyperthermia in rats (5-HT2 effect). The results indicate that sertraline and citalopram given repeatedly decrease the responsiveness of 5-HT1A (presynaptic) and 5-HT2 receptors but increase the responsiveness of 5-HT1B receptors to respective agonists.

1-Naphthylamine↗

PubMed1992

The effect of antidepressant drugs on the locomotor hyperactivity induced by MK-801, a non-competitive NMDA receptor antagonist.

It was found earlier that imipramine, amitriptyline and citalopram enhanced the locomotor hyperactivity induced by MK-801, a non-competitive NMDA receptor antagonist, in rats. Now, three other antidepressants: (+)-oxaprotiline, an inhibitor of the uptake of noradrenaline, (-)-oxaprotiline, an enantiomer devoid of any effect on the uptake of noradrenaline and fluoxetine, an inhibitor of the uptake of 5-hydroxytryptamine, have been examined in male Wistar rats. All those antidepressants, given in a single dose, increased the MK-801-induced locomotor hyperactivity. That increase was completely antagonized by haloperidol and partly by SCH 23390 and (+/-)-sulpiride; prazosin was inactive. Repeated administration of antidepressants produced a similar but more potent (than acute one) enhancement of the action of MK-801. Also, in that case haloperidol and SCH 23390 produced the strongest antagonistic effect; (+/-)-sulpiride and prazosin had a distinctly less potent action. Another effect of MK-801, anticonvulsant activity (electroshock-induced convulsions), was not increased by the antidepressants studied. These results indicate that antidepressants with a different pharmacological profile, increased the MK-801-induced locomotor hyperactivity, this effect being probably indirectly mediated, at least in part, by a dopamine mechanism.

Animals↗

PubMed1992

Effects of MK-801 and antidepressant drugs in the forced swimming test in rats.

The effects of MK-801, a non-competitive NMDA receptor antagonist, and of antidepressant drugs were studied in the forced swimming test in rats. MK-801 reduced immobility time. Combined treatment with MK-801 + imipramine induced a stronger effect in Porsolt's test than administration of either drug alone. Citalopram was inactive when given alone but it potentiated the antidepressant-like effect of MK-801. Haloperidol and prazosin antagonized the effect induced by MK-801 + IMI or CIT. Mianserin interacted with MK-801 in a similar way but to a lesser extent. Its effect was antagonized by haloperidol but not by prazosin. The reduction of the immobility time was also observed in those experimental paradigms in which the locomotor activity was not increased. The results indicate that synergism may exist between antidepressants and MK-801.

Animals↗

PubMed1991

Antidepressant drugs increase the locomotor hyperactivity induced by MK-801 in rats.

MK-801, a non-competitive NMDA receptor antagonist, induced the locomotor hyperactivity in rats. Imipramine (IMI), amitriptyline (AMI), citalopram (CIT) given acutely increased the MK-801-induced locomotor hyperactivity. Mianserin (MIA) showed a similar but weaker effect. Haloperidol completely blocked the hyperactivity induced by the antidepressant drug (AD) + MK-801. Prazosin had an only weak antagonistic effect. Repeated treatment with AD increased the MK-801 locomotor hyperactivity to a greater extent than acute treatment. This effect was completely blocked by haloperidol and only partly by prazosin. The obtained results indicate that the dopamine system may be involved, at least in part, in the potentiating effect of the combined treatment with AD + MK-801.

Amitriptyline↗