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Biomedical subjects

J Maj

Publications and source records attributed to J Maj.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Locomotor hyperactivity induced by MK-801 in rats.

The MK-801-induced hyperactivity in rats was antagonized by haloperidol and, to a lesser degree, by SCH 23390, a dopamine D-1 antagonist, and sulpiride, a dopamine D-2 antagonist. Combined treatment with MK-801 + D-amphetamine, or MK-801 + apomorphine caused a stronger locomotor hyperactivity than each of those drugs given alone. The stereotypy evoked by D-amphetamine or apomorphine was not changed by MK-801. Atropine potentiated the effect of MK-801. Prazosin, idazoxan or ritanserin did not affect the MK-801-induced hyperactivity. It was reduced by pretreatment with alpha-methyl-p-tyrosine (alpha-MT) and completely abolished by pretreatment with reserpine, or with reserpine+alpha-MT. Also combined administration of MK-801 + clonidine increased the activity of rats pretreated with reserpine+alpha-MT. Our results indicate that the dopamine system is mainly involved in the locomotor hyperactivity induced by MK-801.

Amphetamine↗
PubMedDate not supplied

Antidepressants given repeatedly increase the alpha 1-adrenoceptor agonist affinity in the rat brain.

Several different antidepressant drugs (AD): imipramine, amitriptyline, citalopram and mianserin were administered to rats at a dose of 10 mg/kg po, twice daily for 14 days. The competition studies showed that AD used enhanced the ability of alpha 1-agonist phenylephrine to inhibit the binding of [3H]-prazosin to its receptors (Ki values being decreased) in the cerebral cortex, thalamus and hippocampus. The present results show that the increase in the affinity of alpha 1-adrenoceptors for their agonist is responsible for the functional alpha 1-adrenergic hypersensitivity found after repeated treatment with different AD.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

Central action of nomifensine.

Nomifensine, a new antidepressant drug, affects the central noradrenergic neurons in the rat. Nomifensine does not affect the noradrenaline level in the brain, but retards the depletion of noradrenaline after inhibition of its synthesis. Apomorphine and dimethylaminoadamantane accelerate the depletion of noradrenaline and amphetamine does not affect it. Nomifensine potentiates the flexor reflex of the hind paw of a spinal rat and depresses the body temperature.

Animals↗
PubMedDate not supplied

[Werner's Syndrome].

A typical case of Werner's syndrome was described. All characteristic features were present i.e.: atrophy of muscle and subcutaneous tissue, especially in distal parts of limbs, reduced and gray hairs, numerous atrophic ulcers and hyperkeratotic lesions in points under the pressure (elbow, feet), diffused osteoporosis in all bones, the most intensive in hands and feet, activity dental caries, bilateral cataract, high pitched, horse voice, caused by atrophy of voice cords, endocrinologic disturbances especially concerning testosterone, follicle stimulating hormone, and prolactin, hypoplasia of external genitals, the abnormal blood glucose curve. Far reaching resemblance of the Werner's syndrome to the physiological senility was emphasized. Good reaction to anabolic drugs was described.

Anabolic Agents↗
PubMedDate not supplied

Pharmacological effects of oxaprotiline enantiomers on the central serotonin system.

The study examined the effect of both oxaprotiline (OXA) enantiomers on the serotonin system in rats and mice. (+)-OXA and (-)-OXA partly inhibit the behavioral syndrome induced by 8-OH-DPAT and 5-methoxy-dimethyltryptamine (5-MeODMT) in normal and reserpinized rats. Imipramine and desipramine produced a similar but less potent effect. (+)-OXA and, to a lesser extent, (-)-OXA antagonized the m-chlorophenylpiperazine (m-CPP)-induced hypothermia in mice. Imipramine and desipramine produced no such effect. (+)-OXA attenuated the head-twitch response to L-5-HTP in mice, but (-)-OXA has no such action. Neither enantiomer inhibited the fenfluramine-induced hyperthermia in rats nor antagonized m-CPP-induced stimulation of hind limb flexor reflex of spinal rat. The obtained results indicate that both enantiomers may have a 5-HT1B-antagonistic action and a less potent 5-HT1A-antagonistic one; on the other hand, they shown no 5-HT2-antagonistic activity.

5-Hydroxytryptophan↗
PubMedDate not supplied

The effect of repeated administration of imipramine, citalopram and mianserin on responsiveness of central serotonergic, alpha 2-adrenergic and cholinergic system in mice.

The effect of antidepressant drugs: imipramine, citalopram and mianserin given either in a single dose or twice a day for 14 days in a dose of 10 mg/kg was investigated in mice in tests for the responsiveness of central serotonergic (L-5 hydroxytryptophan-induced head twitches), alpha 2-adrenergic (donidine hypoactivity) and cholinergic (oxotremorine syndrome) systems. The effect of L-5 hydroxytryptophan was inhibited by repeated administration of citalopram and mianserin but unchanged by administration of imipramine. After a single administration only mianserin inhibited the L-5 hydroxytryptophan effect. Given repeatedly, the investigated antidepressant drugs did not affect the effect of clonidine; only mianserin potentiated the hypoactivity when given in a single dose. Repeatedly administered antidepressant drugs did not affect the action of oxotremorine, although imipramine (but not citalopram or mianserin) antagonized it after a single administration. The results indicate that under the present conditions repeatedly given mianserin and citalopram, but not imipramine, antagonize behavioral effects of L-5 hydroxytryptophan. No one of the investigated antidepressant drugs given repeatedly changed the responsiveness of alpha 2 -adrenergic and cholinergic systems to their agonists. It might be concluded that the changes in alpha 1-adrenergic and dopaminergic systems, observed previously after repeated administration of antidepressant drugs, are selective.

5-Hydroxytryptophan↗
PubMedDate not supplied

Antidepressant activities of WEB 1881, a new nootropic agent.

The central action, particularly potential antidepressant activity of WEB 1881, a new nootropic drug related to piracetam, was investigated in rats and mice. WEB 1881 antagonizes the reserpine- and apomorphine-induced hypothermia, potentiates the behavioral effect of DOPA and dihydroxyphenylserine, as well as the TRH-induced hyperthermia. Piracetam was only effective in the reserpine and DOPA tests. WEB 1881 is inactive in immobility test of Porsolt et al. It enhances the hind limb flexor reflex of the spinal rat, this effect being antagonized by prazosin and cyproheptadine. It exerts no effect on head twitches induced by L-5-hydroxytryptophan. The studied compound increases the noradrenaline and dopamine and turnover in the forebrain and brain stem. WEB 1881 given repeatedly potentiates the clonidine-induced aggressiveness and has no effect on the locomotor hyperactivity induced by D-amphetamine. The results indicate that in a number of tests WEB 1881 acts like other antidepressant drugs (but in others not), moreover, they suggest that this action is--at least partly--mediated by the central noradrenaline system.

Aggression↗
PubMedDate not supplied

Some central effects of repeated treatment with fluvoxamine.

We investigated the effect of repeated treatment with fluvoxamine, a selective serotonin uptake inhibitor, on behavioral effects of dopaminomimetics and methoxamine and on the animal behavior in the "behavioral despair" test. A repeated treatment with fluvoxamine (twice daily for 14 days) potentiated in mice and in rats (weaker) the amphetamine-induced hyperactivity. The hyperactivity induced by nomifensine in mice remained unaffected by fluvoxamine. The stimulation of locomotor activity by intracerebroventricularly administered methoxamine was not affected by repeated treatment with fluvoxamine. Given three times fluvoxamine had no effect on the immobilization time in the "behavioral despair" test in rats. The results indicate that fluvoxamine given repeatedly acts differently than citalopram, another selective serotonin uptake inhibitor, and differs also from other antidepressant drugs.

Animals↗
PubMedDate not supplied

The central action of 1-(2-pyrimidinyl)-piperazine, an ipsapirone metabolite.

The central action of 1-(2-pyrimidinyl)-piperazine (1-PP), a metabolite of ipsapirone, was studied in mice and rats. 1-PP decreased the locomotor activity and slightly increased the body temperature at an ambient temperature of 21 degrees C, not changing it at an ambient temperature of 28 degrees C. The examined substance antagonized clonidine effects (hypothermia, locomotor hypoactivity, stimulation of the hind limb flexor reflex of the spinal rat). Stimulation of the flexor reflex by St 587, an alpha 1-adrenoceptor agonist was not blocked by 1-PP. 1-PP-induced stimulation of the flexor reflex was blocked by cyproheptadine, ketanserin and pirenperone, but not by prazosin or yohimbine. Given in high doses, 1-PP evoked a flat body posture syndrome, but not forepaw treading or head twitches. The obtained results indicate that 1-PP has mainly an alpha 2-adrenolytic action and differs from ipsapirone in its profile.

Animals↗
PubMedDate not supplied

[Usefulness of photochemotherapy in allergic diseases of the skin].

PUVA treatment was applied in 16 patients with chronic urticaria (7 with solar urticaria, 2 with cold urticaria and 7 with urticaria of unknown etiology), 26 with chronic disseminated eczema and 41 with atopic dermatitis. In all 9 patients with physical urticaria, a clear-cut improvement was observed. The results from the treatment of chronic urticaria of unknown etiology were considerably poorer (improvement in 2 out of 7 cases). In patients with chronic disseminated eczema, a full remission was present in 5 and considerable improvement in 20 cases. In group of 41 patients with atopic dermatitis, 52 cures were carried out; in 8 patients the cure was repeated 2-3 times at 1,0-0,5-year intervals. Complete recovery was achieved in 34 and significant improvement in 16 out of them. The results presented seem to indicate the effectiveness of PUVA treatment to some allergic skin diseases, the more so that the number of exposures required to obtain a considerable improvement, or even full remission, is comparatively low (3-21 occasions), which reduces the risk of complications.

Adolescent↗
PubMedDate not supplied

Some central effects of tiflucarbine, a new potential antidepressant drug.

Tiflucarbine (TVX P 4495), a new putative antidepressant drug (AD) with a chemical novel among AD's [9-ethyl-4-fluoro-1-methyl-7,8,9,10-tetrahydrothieno (3,2-e)-pyrido(4,3-b)indole lactate], a potent inhibitor of the 5-hydroxytryptamine (5-HT) uptake, was studied in rats and mice, mostly with regard to its possible effect on the noradrenaline (NA) uptake and 5-HT postsynaptic receptors. Tiflucarbine exerted no effect on the reserpine hypothermia, attenuated the apomorphine hypothermia and enhanced the TRH-induced hyperthermia. It did not prevent tryptamine convulsions or the fenfluramine-induced hyperthermia, and inhibited the L-5-hydroxytryptophan-induced head twitches (at a high dose only). It stimulated the hind limb flexor reflex preparation of the spinal rat in cyproheptadine-reversible manner. In the behavioral despair test it shortened the immobility time. Tiflucarbine administered repeatedly enhanced the D-amphetamine-induced locomotor hyperactivity and inhibited the clonidine-induced aggressiveness. The results indicate that tiflucarbine exhibits characteristics of a poor inhibitor of the NA uptake (irrespective of its strong inhibitory effect on the 5-HT uptake), and has no effect on 5-HT2 postsynaptic receptors. When used repeatedly, it enhances--like other AD--responsiveness of the central dopamine system.

Aggression↗
PubMedDate not supplied

Central antiserotonin action of fluperlapine.

The effect of fluperlapine--a new nonclassical neuroleptic--on the central serotoninergic system was studied. Fluperlapine antagonizes the head-twitch response induced by 5-hydroxytryptophan in mice and rats (the ED50 values are 0.3 mg/kg ip and 0.89 mg/kg ip respectively), counteracts forepaw clonic convulsions and tremor induced by tryptamine in rats (ED50 = 9.0 mg/kg ip and 7.5 mg/kg ip respectively), and abolishes hyperthermia induced by fenfluramine. In the flexor reflex preparation in spinal rats fluperlapine depresses the reflex only when given in higher doses. The drug given in low doses abolishes the stimulation of the flexor reflex evoked by quipazine and LSD (serotonin agonists) but not by clonidine (noradrenaline agonist). Higher doses of fluperlapine antagonise also the stimulatory effect of clonidine. Our findings demonstrate that fluperlapine shows potent central antiserotonin activity.

Animals↗
PubMedDate not supplied

Central beta- and alpha-adrenolytic activities of adimolol.

The central adrenergic blocking activity of adimolol (ADL) was studied in rats and mice in the tests which can differentiate beta-, alpha 1-, and alpha 2-adrenolytic effects. Clenbuterol- and salbutamol-induced sedation in rats (open field test) and clenbuterol-induced hyperthermia (at high ambient temperature) were antagonized by low doses of ADL (0.1-1.0 mg/kg ip). ADL (10 mg/kg ip) attenuated the clonidine-induced aggression in mice, and its higher doses (20 and 40 mg/kg ip) depressed the hind limb flexor reflex of the spinal rat and counteracted the stimulatory action of clonidine. ADL at doses from 2.5 to 40 mg/kg ip affected neither the clonidine-induced sedation in rats and mice (locomotor activity, open field test), nor the hyperthermia (at high temperature). The hypothermia (at a room temperature of 21 degrees C) induced by clonidine was partially antagonized. The Ki values for ADL displacement of 3H-dihydroalprenolol and 3H-prazosin binding in the rat cerebral cortex were 1.2 nM and 951 nM respectively. These results indicate that ADL is a potent antagonist of central beta-adrenoceptors and has a weaker alpha 1-adrenolytic action. The central alpha 2-antagonistic effect is either very weak or absent.

Adrenergic alpha-Antagonists↗
PubMedDate not supplied

The anti-inflammatory and analgesic activity of N-3-pyridoyltryptamine (tryptamide).

In this study we compared the antiinflammatory and analgesic properties of N-3-pyridoyltryptamine (tryptamide, TRP) with those of standard non-steroid anti-inflammatory drugs (phenylbutazone, indometacin, piroxicam and ibuprofen). Antiinflammatory properties were investigated in the carrageenin-, serotonin-, kaolin-, formalin- and xylene-induced edema tests and in the cotton pellet granuloma test. The analgesic properties were studied in the writing, hot plate and electrical stimulation tests. In the majority of the applied tests TRP reveals the activity resembling this of phenylbutazone, and several times weaker than the effect of the remaining standard drugs. The ulcerogenic effect of TRP is very weak, and its effective doses are several times higher than these of the compared substances. Hence the therapeutic indices of TRP are several times higher than these of the other examined substances. The obtained results indicate that TRP is a putative anti-inflammatory and analgesic drug, much safer that other known substances with a similar pharmacological profile.

Animals↗
PubMedDate not supplied

The influence of neuroleptics on the behavioural effect of 5-hydroxytryptophan.

The antagonism of neuroleptics of various groups (chlorpromazine, chlorprothixene, clopenthixol, clozapine, flupenthixol, fluphenazine, haloperidol, levomepromazine, mepazine, perazine, perphenazine, pimozide, prochlorperazine, promazine, spiperone, thiopromazine, thioridazine, trifluperazine, trifluperidol, triflupromazine) towards L-5-hydroxytryptophan (5-HTP) was assessed on the basis of inhibition of characteristic head-twitches. ED50 was assayed in mice and rats. The results indicate that all investigated neuroleptics inhibit the action of 5-HTP and their ED50 values are, as a rule, lower than the values of ED50 for catalepsy. That action is for the majority of neuroleptics more pronounced in mice than in rats. The present paper disucsses possible serotonergic, dopaminergic and also noradrenergic mechanism of action of neuroleptics in the 5-HTP test.

5-Hydroxytryptophan↗