One of the method of treatment hyperplasia and cancer of prostate is hormone therapy, which reduce effects of androgens on the tumor cells . However, due to the lack of modulating effects of testosterone, other organs and systems suffer, in particular, the nervous system. From the point of view of electrophysiology, practically not found works describing changes of bioelectrical activity in all parts of the somatic reflex arc under the conditions of hypoandrogenemia. Thus, the study changes of bioelectrical activity a somatic reflex arc, as the functional unit of the motor system seems to be relevant.
Under the conditions of hypoandrogenemia there is a pronounced decrease excitability of the neuromuscular apparatus, due to the nerve structures. In favor of it increases threshold of a calf muscle response in 4 times with its indirect stimulation, while the threshold of excitation of a calf muscle increased only on
41 %. In addition, there was an increase duration of the latent period on 31.93% and total duration of AP on 101.99%. At the same time bioelectric activity of a muscle increased that is testified by increasing amplitude of AP on 65%. Androgen deficiency is also caused decrease in the limiting frequency of excitation transmission through a neuromuscular synapse, which may indicate an increase in the phenomenon of homosynaptic depression.
Regarding the central link of the reflex arch, under the conditions of experimental hypoandrogenemia, there is a relative increase in excitability of medium- and high-threshold motoneurons on the background of general decrease excitability of a motor apparatus SC, as evidenced by increase a threshold of motoneurons response on 35.29 %. Androgen deficiency is also led to a slight increase in the duration of the latency period at 4.59% and decreased lability, which may be manifestations of homosynaptic depression and deepening of presynaptic spinal inhibition from a side of the interneuron pool.
Chronaxia is decreased to 71.9 %. Androgen deficiency is also contributes to a significant increase of lability, despite the increase of duration a latency period on 72.73 %, and general duration of the response on 25.53 %. The amplitude of the total AP is significantly increased on 76.42%.
Androgen deficiency in the structures of posterior horn of SC caused multidirectional processes. Thus, in animals of the experimental group, despite the increase a threshold of potential in the dorsal surface of SC on 130%, the period of latency and total duration of response is decreased to 47.27 % and 78.40 %, respectively. Chronaxia is decreased on 18.28 %. The activity of interneuron pool is increased, primarily due to the inhibition of segmental and non-segmental interneurons. It is shown by increased amplitude of the afferent peak on 98.3 %, N1 - component on 51.08 %, N2 on 49.64 %, N3 on 207.41 % . Neurons of gelatinous substance are also showed a tendency to increase activity (119.61% relatively to the control group).
Regarding to a nerve transmission in the structures of posterior horn of the SC, under the conditions of hypoandrogenemia was observed inhibition of signals in a frequency more than 20 Hz.
A comprehensive assessment of the activity of the children of the segmental reflex arch of the spinal cord was carried out for the minds of experimental hypoandrogenism. It was found that under these conditions, the excitability of the neuromuscular apparatus is significantly reduced against the background of increased latency and lability, as well as increased homosynaptic depression at the interneuronal and neuromuscular synapses.
In-depth knowledge of the nature of long-term hypoandrogenemia on the condition of afferent and efferent fibers, in particular the relative increase in excitability of low- and medium-threshold fibers against the background of a general increase in the excitation threshold and a significant increase in lability and bioelectrical activity.
This paper reveals the existing or hidden links in the mechanisms of sensory and motor disorders under the conditions of a prolonged hypoandrogenemia, which occur on the level of a segmental reflex arc of SC. Identifying the location of such disorders, their functional relationships will allow to develop or supplement the targeted pathogenetic steps within therapeutic approaches and to find out possible measures for diagnose and prevention of development the neuropathic complications of androgen deficiency.
