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Biomedical subjects

G Hebenstreit

Publications and source records attributed to G Hebenstreit.

8 recordsLinked to original sources
PubMed1989

Neurochemical perspectives to the function of monoamine oxidase.

Dopamine (DA) is degraded in part by MAO, an intraneuronal and glial enzyme localized at the outer mitochondrial membrane. DA is a good substrate for MAO-B and selegiline enhances DA-transmission and improves akinesia of Parkinson's disease (PD) by selective MAO-B blockade. Immunocytochemistry (ICC) and histochemistry (HC) demonstrate that neurons of substantia nigra (SN) lack MAO near totally (but see Moll et al 1988). Consequently, inhibition of MAO-B in this brain area occurs mainly in glial cells. Therefore an increase of DA in glia seems to be of long-lasting therapeutic benefit in PD. In addition, synthesis of hydrogen peroxide generated via MAO-B is blocked by selegiline. By this toxicity by endogenous free radicals is diminished. Furthermore, exogenous neurotoxicity by MAO-B substrates can be prevented by inhibition of MAO-B, while such MAO-A substrates are metabolized at the level of the MAO-A containing endothelium of capillaries. As conclusion, selegiline is a safe inhibitor of MAO-B that reduces neurotoxicity possibly triggering PD. (Table: see text).

Brain↗
PubMed1989

[Neurochemical perspectives of the function of monoamine oxidases].

Monoamine oxidase (MAO) and its subtypes MAO-A and MAO-B show different distribution in post mortem human brain areas. While MAO-B is the predominant type in glial tissue, intraneuronal MAO is either of type A (locus coeruleus, only 10% of substantia nigra neurons stain MAO-A), while raphe neurons contain entirely MAO-B. Inhibition of MAO-subtypes leads to accumulation of biogenic amines in glial tissue while there is a selective intraneuronal influence differing between various brain areas. Generation of toxic end-products (eg. aldehydes, hydrogen peroxide, ammonia) may contribute to trigger or at least to progress Parkinson's disease.

Animals↗
PubMed1989

Efficacy and tolerability of moclobemide compared with imipramine in depressive disorder (DSM-III): an Austrian double-blind, multicentre study.

The antidepressant efficacy, tolerability, and safety of moclobemide, a reversible, monoamine oxidase-A inhibitor, were compared with those of imipramine in parallel groups of patients with a major depressive episode, in a 4-week, multicentre (17 centres), randomised study. A total of 381 patients were randomly allocated to either treatment; they were not required to avoid tyramine-rich foods. Drop-out rates were comparable in both groups at about 17%. Judged primarily on the HRSD, no significant differences in efficacy were observed between the groups, but the number of patients presenting with adverse events, as well as the total number of adverse events, was greater with imipramine. Cardiovascular tolerability was satisfactory and physical examination, body weight, and laboratory values were essentially unaffected in both groups.

Adjustment Disorders↗
PubMed1979

[Indoor treatment of involutional depressions in cerebro-vascular insufficiency (author's transl)].

In this study we are reporting about our results concerning a combined therapy of short-time hospitalized patients, who suffered from an involutional depression and a cerebro-vascular-insufficiency. All patients had been treated outdoor without sufficient results before this. We could see, that all patients who had suffered their acute state within the last 18 months had good or very good improvements. Patients suffering already for several years showed no improvement in spite of all our efforts to promote the cerebral blood flow, the metabolic situation and the environment situation. These results proved, that one should start with a proper therapy of infusions and workshop rehabilitation immediately after the first sign of an involutional depression and cerebro-vascular-insufficiency.

Adult↗