[COMPARATIVE ANALYSIS OF SEROTONIN LEVELS IN RAT PLATELETS, SERUM AND BRAIN ON THE AGING].

Serotonin functions as neurotransmitter in central nervous system and is involved in the regulation of vascular tone, gastro-intestinal motility and blood coagulation in the periphery. The appearance of new data on the significant correlation between serotonin levels in platelets and cerebrospinal fluid (Audhya et al., 2012) renewed interest in the hypothesis in which the platelet is seen as a model of cerotoninergic neuron.

Myopathy-causing Q147P TPM2 mutation shifts tropomyosin strands further towards the open position and increases the proportion of strong-binding cross-bridges during the ATPase cycle.

The molecular mechanisms of skeletal muscle dysfunction in congenital myopathies remain unclear. The present study examines the effect of a myopathy-causing mutation Q147P in β-tropomyosin on the position of tropomyosin on troponin-free filaments and on the actin–myosin interaction at different stages of the ATP hydrolysis cycle using the technique of polarized fluorimetry. Wild-type and Q147P recombinant tropomyosins, actin, and myosin subfragment-1 were modified by 5-IAF, 1,5-IAEDANS or FITC-phalloidin, and 1,5-IAEDANS, respectively, and incorporated into single ghost muscle fibers, containing predominantly actin filaments which were free of troponin and tropomyosin.

[THE ROLE OF HEME-CONTAINING GLOBINS IN HYPOXIC NO-SIGNALING OF VERTEBRATE CELLS].

Nitric oxide is one of the most important signaling molecule of living organisms. It may be produced by two ways: from arginine by means of NO-syntases and from nitrite by means of nitrite reductases. The last way is realized mostly at hypoxic state of organisms and heme-containing globins of vertebrates (hemoglobin, myoglobin, cytoglobin, neuroglobin) mediate the transformation of NO2 into NO by means of their nitrite reductase activities.

[The influence of small doses of exogenic nitrite on oxidative modifications of water-soluble proteins of rat cardiac and skeletal muscle].

The influence of small doses of exogenic nitrite on reversible and irreversible oxidative modifications of water-soluble proteins of rat cardiac and skeletal muscle was studied with the aid of redox 2D-electrophoresis and colorimetric determination of protein carbonyl group, correspondingly. To explain the absence of significant changes under hypoxia induced by nitrite the known hypothesis about nitrite inhibition of some sites of mitochondrial electron transporting chain decreasing free radical quantity was discussed.

Quantitative evaluation of tryptophan oxidation in actin and troponin I from skeletal muscles using a rat model of acute oxidative stress.

Increased levels of "ROS" cause oxidative stress and are believed to play a key role in the development of age-related diseases and mammalian aging, e.g. through the oxidation of residues, at or close to, the protein surface.