Rodinsky A. G., Tkachenko S. S., Marazha I. A., Romanenko L. A., Knyazheva E. V.

INFLUENCE OF ANDROGENS ON THE FUNCTIONING OF THE SOMATIC REFLEX ARC


About the author:

Rodinsky A. G., Tkachenko S. S., Marazha I. A., Romanenko L. A., Knyazheva E. V.

Heading:

LITERATURE REVIEWS

Type of article:

Scentific article

Annotation:

Many neurons and glial cells express androgen receptors. Research in a number of models in vitro and in vivo has shown that steroid hormones, in addition to the classical genomic model of action, can influence the course of cellular processes by non-genes. Androgens can interact with intracellular calcium regulators. A further effect of androgens is the rapid change [Ca2 +]i. Ca2 + functions as an omnipresent second messenger molecule and the modulation of intracellular Ca2 + levels affects a wide range of cellular processes, including cell proliferation, apoptosis, necrosis, mobility, and gene expression. The androgen receptor is predominantly cytoplasmic in the absence of a hormone and is rapidly transmitted to the nucleus after application of testosterone. Androgens acting through androgen receptors may be important neurotrophic factors for muscle development. There is evidence of a positive effect of testosterone substitution therapy with spinal cord injury on muscle size without traditional overload. Androgens reduce the contribution of neuromuscular transmission to the development of the fatigue of the diaphragm with repetitive stimulation, mainly due to high-speed neuromotor units, whereas in units containing fibers of type I or IIa, hormonal therapy has no effect. There is a laboratory confirmation that treatment with pharmacological testosterone increases the level of mRNA encoding the synthesis of choline acetyltransferase (HAT) in motor neurons of the spinal cord in adult male rats. An increase in the content of HAT mRNA in motor carriers can potentially lead to an increase in the activity of the HAT on the axon terminal, thereby increasing the presynaptic ability to synthesize acetylcholine. The use of androgens in castrated animals resulted in a significant and prolonged increase in BDNF expression in the facial motor neurons and reduced the amount of synaptic waste after facial nerve transplantation, as well as the acceleration of axon regeneration. The effect of testosterone is also associated with an increase in the size of the catheter neurons, the growth of neurites, ductility and synaptogenesis. The hormone reduces the degree of damage to the spinal cord in vitro. Neurotrophic factors and steroid hormones interact in the processes of regulation of various neuronal processes, such as the growth of neurites, differentiation and neuroprotection. The use of testosterone for therapeutic purposes protects motor neurons from atrophy caused by the death of adjacent motor neurons. There are studies that androgens greatly contribute to the reorganization of the neural chains of the spinal cord of adults, in particular, are crucial for maintaining the organization of synaptic inputs of spinal motor neurons. Androgens provide neuroprotection of CNS neurons due to the lack of growth factors in apoptosis. Androgens can affect the turnover of a cytoskeleton matrix responsible for the structure of the axon. Testosterone has a neuroprotective effect in nerve fibers and the testosterone deficiency can lead to various forms of degeneration of the nerves, which may ultimately result in even anatomical changes. Neuroprotective effects are manifested at the physiological concentration of the hormone and due to the interaction with the receptors of androgens. Some data suggest that neuroprotection of androgens may be mediated by the mitigation of oxidative stress. Thus, directly through membrane or nuclear receptors, or indirectly by metabolic effects, androgens affect all the links in the somatic reflex arc. However, very few studies show the peculiarities of their functioning, in vivo, and electrophysiological studies have almost not been conducted, which provides the basis for further searches for answers to questions about the influence of male sex hormones on the nervous system.

Tags:

testosterone, androgens, receptors, nervous system, neuron, axon

Bibliography:

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Publication of the article:

«Bulletin of problems biology and medicine» Issue 1 Part 1 (148), 2019 year, 61-65 pages, index UDK 612.83:612.662.9:618.173-073.7/-076-085:615.2.1-092.9

DOI: