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A Randrup

Publications and source records attributed to A Randrup.

12 recordsLinked to original sources
PubMed1991

[On spatio-temporality. A psychiatric and interdisciplinary study].

There is no scientific knowledge without a method, no method without a minimum of theory and no theory without a general frame of reference. The concepts of space and time constitute undoubtedly the most comprehensive frame of reference; it is relevant both to the interior, experienced world of man and to the universe in which he lives. The concepts of space and time, which have emerged from various disciplines such as philosophy, cosmology, physics, biology, neurophysiology, ethology and psychiatry show a certain number of mutual relations and even connections. Characteristically, these concepts fit in with the levels, integrations, communications and self-regulations, all the structural properties, which are emphasized by the model of mental disturbances, created by application of a special systems approach, the "systemal method", to the psychiatric clinic. This structural isomorphism between the mental disturbances and the cognitive concepts of space-time reinforce by feed-back the validity of the systemal method. It also indicates the relevance of the basic sciences to the further development of psychiatry.

Humans↗
PubMed1988

Stereotyped behaviour in animals induced by stimulant drugs or by a restricted cage environment: relation to disintegrated behaviour, brain dopamine and psychiatric disease.

Stereotyped behaviour can be produced in animals both by stimulant drugs (amphetamine, methamphetamine, cocaine, etc.) and by a restricted cage environment. Strong evidence indicates that the effect of stimulant drugs is mediated through a primary effect on brain dopamine, and further knowledge is now being acquired through studies on dopamine receptors, tolerance and reverse tolerance to amphetamines and the neural connections of dopaminergic sub-systems with other sub-systems in the brain. The forms of stereotypy induced by a restricted cage environment have been compared with other effects of this type of environment on behaviour and general health. This has led to a hypothesis that stereotyped behaviour may function as a survival (or defence) strategy in an unfavourable milieu. Some evidence indicates that brain dopamine is also involved in the mediation of stereotyped behaviour induced by the environment. The relevance of these results in clinical psychiatry is discussed. Stereotypy (and related disintegrated behaviour) is a well known feature of several mental diseases.

Amphetamines↗
PubMed1977

Uptake inhibition of biogenic amines by newer antidepressant drugs: relevance to the dopamine hypothesis of depression.

The dopamine theory of depression was studied by assessing the effect of antidepressant drugs on uptake of dopamine, noradrenaline, and serotonin in synaptosomes from rat brain. Five newer drugs--butriptyline, maprotiline, trimipramine, iprindole, and mianserine--exhibited rather potent inhibition of 3H-dopamine uptake in corpus striatum, as their IC50 values, which were in the order of 10(-6)-10(-5) M, were only about 50 times higher than for nomifensine (IC50 = 10(-7) M). The five drugs were weak, compared to chlorimipramine, on 14C-serotonin uptake in the whole forebrain, as their IC50 were about 10(-5) M. Butriptyline, trimipramine, and iprindole were very weak uptake inhibitors of 3H-noradrenaline in the occipital cortex. Their IC50 values were about 10(-6) M, which is almost 1000 times higher than for desmethylimipramine. These results are discussed in relation to comprehensive recent literature as further indicating a link between dopamine and depression.

Animals↗
PubMed1976

Effects of thymoleptics on behavior associated with changes in brain dopamine. II. Modification and potentiation of apomorphine-induced stimulation of mice.

The thymoleptics potentiate and modify the behavioral effects of apomorphine (probably the most specific dopaminergic agonist) as well as those of Dopa. The effect of the thymoleptics is not abolished by emptying of amine stores, and this together with other evidence suggests that these drugs facilitate the access of apomorphine to the dopamine receptors. The effects of thymoleptics on elements of animal behavior that can be associated with brain dopamine appear interesting on the background of a considerable body of evidence indicating an association of brain dopamine with depression and mania (references).

Animals↗
PubMed1976

Effects of thymoleptics on behaviour associated with changes in brain dopamine. I. Potentiation of dopa-induced gnawing of mice.

The thymoleptics imipramine, desipramine, protriptyline, nortriiptyline, chlorimipramine and amitriptyline all potentiate gnawing of mice induced by Dopa following decarboxylase inhibitior Ro 4-4602. The gnawing behavior is probably associated with the increase in brain dopamine resulting from this treatment. Thymoleptics also affect other types of behaviour associated with brain dopamine. The relevance of these effects to clinical antidepressive effect and their possible utilization for preclinical screening tests is discussed.

Animals↗
PubMed1975

Behavioral effects of thymoleptics in vervet monkeys (Cercopithecus aethiops).

Desmethylimipramine (DMI) exerts diverse quantitative effects on the gross behaviour of monkeys. Excitatory as well as sedative effects were observed, which varied according to the general animal temperament. Results resembling those obtained with DMI were observed using chlorimipramine and iprindole, although the effects of iprindole were less marked. Chlorimipramine also produced immobilization and postural change. The results are discussed in relation to behavioral effects of thymoleptics in humans, and the use of monkeys in preclinical testing of thymoleptic drugs is suggested.

Animals↗
PubMed1975

The monoamine oxidase B inhibitor deprenyl potentiates phenylethylamine behaviour in rats without inhibition of catecholamine metabolite formation.

The drug l-deprenyl has been reported to have antidepressant properties, and in the present study three possible mechanisms of action were investigated in animal experiments. l-Deprenyl, which is a type B monoamine oxidase (MAO) inhibitor, was compared to clorgyline, an MAO A inhibitor with regard to its inhibitory effect on the formation of three major catecholamine metabolites, homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC) and 3-methoxy-4-hydroxyphenylglycol (MOPEG) in the rat brain in vivo. Apart from a difference in dose levels the two drugs showed no difference in the dose--response pattern of all three metabolites. Clorgyline inhibited the formation of HVA, DOPAC and MOPEG with an ED50 of about 0.2 mg/kg s.c. and l-deprenyldopamine and noradrenaline are formed by the same type of monoamine oxidase(s), probably type A, in the rat brain in vivo. Antidepressant properties of l-deprenyl therefore seem to be independent of catecholamine deamination. l-Deprenyl but not clorgyline (2 or 8 mg/kg s.c.) potentiated the stereotyped sniffing behaviour induced by beta-phenylethylamine, a specific substrate for type B monoamine oxidase. This result is discussed in relation to a new hypothesis of phenylethylamine and dopamine involvement in depression. l-Deprenyl was 10,000 times less potent than DMI as inhibitor of noradrenaline uptake in crude synaptosomes from the occipital cortex of rat brain. Inhibition of noradrenaline uptake was therefore excluded as a possible mechanism for the antidepressant action of l-deprenyl.

Animals↗
PubMed1975

Apomorphine-induced stereotyped biting in the tortoise in relation to dopaminergic mechanisms.

A biting behavior in the Moroccan pond tortoise (Clemmys caspica leprósa) after apomorphine administration is described. The biting behavior was antagonized by the specific anti-dopaminergic drug haloperidol (10 mg/kg) and trifluperazine (15 mg/kg). The behavior was compared to similar behaviors in birds and mammals. The dopamine metabolites, homovanillic acid and 3,4-dihydroxyphenylacetic acid, were measured by a gas chromatographic method in the tortoise brain. From the effects on behavior and the changes in the level of these metabolites upon drug administration it was concluded that the dopamine system in the tortoise is qualitatively similar to that in birds and mammals but less sensitive to blockade.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Spectrum of pharmacological actions on brain dopamine. Indications for development of new psychoactive drugs. Discussion of amantadines as examples of new drugs with special actions on dopamine systems.

Amantadine (D1) and 1,3-dimethyl-5-aminoadamantane (D145) as examples of new drugs with special actions on dopamine systems are discussed. D1 or D145 decreased significantly apomorphine or amphetamine-induced stereotypy in rats but in experiments with chronic pretreatment with amantadines -- potentiation of stereotypy was observed. D145 (20 mg/kg) abolished stereotypy in these conditions. In biochemical experiments D1 or D145 were neither like apomorphine nor like amphetamine. Its concluded that D1 and D145 in addition to their amine releasing properties have the ability partially to occupy the dopaminergic receptor.

Amantadine↗