1. Introduction

The damages of the peripheral nervous system in patients with diabetes mellitus are recorded in 40–60% of cases and manifests itself in the form of diabetic polyneuropathy. The incidence of

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

diabetic polyneuropathy increases with age and duration of diabetes mellitus [1]. According to recent data, in the last 10 years, in young patients with type 1 diabetes, an increase in the incidence of diabetic polyneuropathy from 24.2% to 62.9% has been observed [2]. Diabetic neuropathy correlates with a high risk of cardiovascular complications [3, 4]. Patients with diabetic polyneuropathy are also at risk for the formation of trophic ulcers that do not heal for a long time and often lead to amputating a limb [5–7]. In the USA, 15% of all patients with diabetes will develop foot ulcers [8].

gold standard in clinical research, it is not useful in clinical practice because it is time-consuming, requires special devices and trained examiners, and has no general consensus regarding its criteria, even after multiple investigations [27]. That is why the experiments on the rats give us possibility to investigate the mechanisms of diabetic polyneuropathy development, to evaluate the quality of treatment, and to propose the new approaches to diagnostic and treatment of

Dynamic Properties of Skeletal Muscle Contraction in Rats with Diabetes

http://dx.doi.org/10.5772/intechopen.70600

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In isometric conditions, analysis of registered effort developed by the muscle due to frequencymodulated stimulation of its nerve is the qualitative indicator of the level of neuro and myopathy

Phenomenological approach in the analysis of pathological processes that influence the mechanical properties of the muscle makes it possible to establish important relationships between the real macroscopic parameters of the muscle state, such as the strength, length and level of efferent activity. Frequently, the analysis of pathological changes in muscle dynamics is sufficient for the analysis of central regulatory processes, both motor activity and pathological state

The dynamics of contractile component is determined by the delicate interaction of motor neuron pools that appeared in the muscle through the activated motor neuron and the activation of actin and myosin myofilaments interactions. Dependence of muscle force response on value, duration of applied stimulation (force-velocity for the initial site) and on time of achievement and retention of the stationary state of the contractile process makes possible to track the level of pathological processes development that affect the mechanisms of positioning in muscle dynamics. These processes play a huge role in the accurate positional movements of hands and fingers, even minor violations in the control system of these movements

The rapid excitement of contractile apparatus, in the process of prolonged activation of muscle fibers, usually undergoes a slow and stable modification, which can partly be due to the phosphorylation of the so-called light chains of myosin located in the neck of the bridge. A slower dephosphorylation process under conditions of prolonged uninterrupted activation of the muscle fiber causes stable phosphorylation of myosin, which, apparently, increases the mobility of the bridges or changes their orientation. Analysis of amplitude-velocity changes of activated muscle's force response makes it possible to assess the influence of developing pathology on these processes. One of the most effective and widely used methods to identify the dynamic systems' levels pathologies is to determine the reaction in responses to the

harmonic input effects of different velocity ranges of increase stimulating irritations.

2. Dynamic properties of skeletal muscle contraction in rats with diabetes

The study was conducted on 20 white nonlinear laboratory male rats, which were divided into two groups of 10 animals each. The rats in the first group were used as control. Rats in

diabetic polyneuropathy.

pathological processes.

of the organism as a whole.

lead to serious domestic and physiological problems.

2.1. Methods of experiment conduction

Mortality due to diabetes mellitus, complicated by diabetic polyneuropathy, remains high in all countries of the world, regardless of their socioeconomic status [3]. Patients with diabetic polyneuropathy often require outside help, which, of course, is reflected on the quality of their life [9, 10].

Metabolic, vascular and immune theories were proposed to explain the pathogenesis of diabetic polyneuropathy [11]. Independent causes of the risk of this serious complication of diabetes mellitus are age, male gender, unsatisfactory control of the level of glycaemia, elevated lipid levels in the blood, height, overweight and obesity, and insulin treatment [12–16]. Thus, the pathogenesis of diabetic polyneuropathy is multifactorial. It includes the increase of mitochondrial production of free radicals due to hyperglycemia-induced oxidative stress [1]. A number of other factors affect the activity of neurons, mitochondrial function, permeability of membranes and endothelial function. These include the activation of polyol aldose reductase pathway [17], activation of poly(ADP ribose) polymerase [18], and modified Na+/K+-ATPase pump function [19].

In diabetic polyneuropathy, autonomic, motor, large fiber and small fiber nerve functions are attacked [20]. The most frequent variant of defeat of peripheral nervous system at a diabetes is distal symmetric sensorimotor neuropathy [21]. As a rule, this complication occurs in a few years from the onset of the underlying disease [22]. This form of diabetic polyneuropathy develops slowly (chronically), the first symptoms (numbness and paresthesia) occur in the lower extremities, sometimes unilateral [23]. Distal symmetric sensorimotor neuropathy is the cause of the development of chronic neuropathic pain syndrome. Pain is the reason for 40% of patient visits in a primary care setting, and about 20% of these have had pain for more than 6 months [24]. In this form of neuropathy, poorly myelinated and thin nonmyelinated fibers are affected in various combinations. In most cases, at the onset of the disease, the neurological deficit is caused by the damages to fine fibers. Symptoms of their damages are manifested by burning or shooting pain, hyperalgesia, paresthesia, disturbances of pain and temperature sensitivity, ulceration of the feet and a decrease in pain sensitivity from the internal organs. With the defeat of myelinated (thick) fibers, there is a violation of deep and vibrational sensitivity, and a decrease or loss of tendon reflexes.

Diabetic polyneuropathy affects both type 1 and type 2 diabetes patients, although specific differences exist in the underlying pathobiology, pathology and clinical expression of the disease [25]. In type 1 diabetes patients, diabetic polyneuropathy is more rapid and severe.

The nerve conduction study is a reliable and objective diagnostic method to evaluate the diabetic polyneuropathy treatment response [26]. Although a nerve conduction study is regarded as the gold standard in clinical research, it is not useful in clinical practice because it is time-consuming, requires special devices and trained examiners, and has no general consensus regarding its criteria, even after multiple investigations [27]. That is why the experiments on the rats give us possibility to investigate the mechanisms of diabetic polyneuropathy development, to evaluate the quality of treatment, and to propose the new approaches to diagnostic and treatment of diabetic polyneuropathy.

In isometric conditions, analysis of registered effort developed by the muscle due to frequencymodulated stimulation of its nerve is the qualitative indicator of the level of neuro and myopathy pathological processes.

Phenomenological approach in the analysis of pathological processes that influence the mechanical properties of the muscle makes it possible to establish important relationships between the real macroscopic parameters of the muscle state, such as the strength, length and level of efferent activity. Frequently, the analysis of pathological changes in muscle dynamics is sufficient for the analysis of central regulatory processes, both motor activity and pathological state of the organism as a whole.

The dynamics of contractile component is determined by the delicate interaction of motor neuron pools that appeared in the muscle through the activated motor neuron and the activation of actin and myosin myofilaments interactions. Dependence of muscle force response on value, duration of applied stimulation (force-velocity for the initial site) and on time of achievement and retention of the stationary state of the contractile process makes possible to track the level of pathological processes development that affect the mechanisms of positioning in muscle dynamics. These processes play a huge role in the accurate positional movements of hands and fingers, even minor violations in the control system of these movements lead to serious domestic and physiological problems.

The rapid excitement of contractile apparatus, in the process of prolonged activation of muscle fibers, usually undergoes a slow and stable modification, which can partly be due to the phosphorylation of the so-called light chains of myosin located in the neck of the bridge. A slower dephosphorylation process under conditions of prolonged uninterrupted activation of the muscle fiber causes stable phosphorylation of myosin, which, apparently, increases the mobility of the bridges or changes their orientation. Analysis of amplitude-velocity changes of activated muscle's force response makes it possible to assess the influence of developing pathology on these processes. One of the most effective and widely used methods to identify the dynamic systems' levels pathologies is to determine the reaction in responses to the harmonic input effects of different velocity ranges of increase stimulating irritations.
