[An endogenous inhibitor of monoamine oxidase A (tribulin A) from brain: purification and structure identification].

The endogenous monoamine oxidase inhibitor, tribulin, contains several components which selectively (or nonselectively) inhibit monoamine oxidases A and B. The pig brain tribulin component selectively inhibiting monoamine oxidase A was purified and identified as 4-hydroxyphenylethanol using gas chromatography-mass spectrometry. This compound was also found in the rabbit brain tribulin fraction which selectively inhibits monoamine oxidase A but has no influence on monoamine oxidase B.

[Medico-biological aspects of biochemistry of amines and other nitrogen bases].

The art-of-the-state and possible perspectives for studies of the properties of amine oxidases which are medically significant are briefly outlined. Due to the studies conducted at the Research Institute of Biomedical Chemistry of the Russian Academy of Medical Sciences, the authors discuss the results of studies of the following three problems: 1) modified catalytic properties of amine oxidases in experimental intoxications and abnormalities; 2) natural modulators of amine oxidases; 3) synthetic modulators of amine oxidases.

[Natural modulators of the function of the amine oxidase system in the body].

In cerebrospinal fluid (CSF) obtained from patients with chronic alcoholism natural modulators of monoamine oxidase (MAO) activity, containing in human mitochondrial and microsomal fractions or in rat brain mitochondria, have been found. These modulators, which were previously unknown, did not affect the activity of partially purified diamine oxidase from human placenta with 14C-putrescine as a substrate. The MAO modulators from CSF were thermostable (during 3 min at 100 degrees), penetrated through dialysing membrane thus differing from high molecular modulators of MAO previously described.

[The action of befol and its derivatives on monoamine oxidase of different origins].

The effect on deamination of serotonine, dopamine, tiramine and 2-phenylamine of benzamide derivatives befol, moclobemide and LIS-641 was studied. Befol and moclobemide are inhibitors of serotonine deaminating activity of MAO. The different sensitivity of this activity to the effect of the benzamide derivatives in beef or rat brain and human placenta was noted.

[Multiple forms of monoaminoxidase in the rat brain during experimental catatonia].

Catalytic properties of multiple forms (separated by affinity chromatography) of rats brain mitochondrial monoamine oxidase (MAO, MAO-I, MAO-11 alpha, MAO-11 beta, MAO-111) have been studied in the animals selected for propensity to development of catatonic syndrome considered as an experimental model of the catatonic syndrome occurring in schizophrenia. It was shown that in experimental catatonia (as compared with rats of the corresponding control group) there was a dramatic increase in the brain stem of the rate of oxidative deamination of beta-phenylethylamine catalyzed by MAO-III; there was also a statistically significant (albeit less expressed than in the experiments with beta-phenylethylamine) increase in the rate of deamination of tyramine and a decrease in the rate of deamination of serotonin. In the systems with MAO-II beta we detected statistically significant increase in the rates of deamination of tyramine and beta-phenylethylamine in experimental catatonia as compared with corresponding control.