Cellular mechanisms of DENS influence on reparative processes in tissues

Bazarny V. Cellular mechanisms of dynamic electroneurostimulation influence on reparative processes in tissues / V. Bazarny, A. Isaykin, I. Valamina, N. Krokhina, O. Beresneva // 17th ESPRM European Congress of Physical and Rehabilitation Medicine. Venice. 2010. p. 15-16.

CELLULAR MECHANISMS OF DYNAMIC ELECTRONEUROSTIMULATION INFLUENCE ON REPARATIVE PROCESSES IN TISSUES

V. Bazarny, A. Isaykin, I. Valamina, N. Krokhina, O. Beresneva
Ural State Medical Academy, Yekaterinburg, Russia

Aim

Dynamic electroneurostimulation (DENS) is a relatively new technology of rehabilitation medicine combining the principles of electrotherapy and reflexotherapy. Now analgesic effect of DENS is well known and has been proved by numerous researches. DENS has various other effects on the human body including neuroreceptor and regulatory effects. 1 Although some of them require strict proof. The mechanisms of reparative action of DENS are the least-studied. Meanwhile the problem of directed regulation of regenerative processes is still valid. This also set an aim of this research – to study the influence of dynamic electroneurostimulation on reparative processes in tissues after injury.

Methods

The experiment was performed on 60 outbred male rats weighing 120-150 g. The animals were kept in standard vivarium conditions. Experimental models of tibia fracture and skin wounds were used. Modeling of tibia fracture was performed surgically by transversal intersect with excision of 3 mm fragment the diaphysis. Surgical wound was sutured in layers. The postoperative scar was treated by oxytetracycline aerosol. Modeling of skin wound of 1 cm2 was carried out surgically on the dorsal surface of the rats’ body. Surgery intervention was aseptic performed under rometarom (0.1 mL/100 g of body weight) and 0.3% lidocaine anesthesia. DENS procedure was spent on tail skin and on a direct injury projection by DiaDENS-T device at 77 Hz frequency and low power level within 10 minutes since day of surgery and continuing during 7 days. Control rats did not receive such therapy. Experimental animals were taken out of the experiment by decapitation under ether anesthesia for the seventh and tenth day. Reparative processes were controlled by morphological data of the standard histological sections stained with hematoxylineosin. Intensity of cellular reaction was evaluated by computer morphometry (video-computer complex SIAMS-610). Statistical analysis of results was performed on the basis of variational statistics using nonparametric criteria.

Results

In the experiment it was shown that wound defect has been filled by granulation tissue with the inflammation reaction for the seventh day. Complete epithelization of the wound defect was absent. Under the DENS influence the number of neutrophils in wound area was somewhat smaller though exudation reaction remained. According to computer morphometry the number of fibroblastic cells in granulation tissue was increased by 25% compared to the control group (P<0.05). Upon further observation it was determined that full restoration of skin defect occurred in average 10 days (in control rats – in 12 days). At the same time more delicate connective tissue scar formed under the DENS influence.

In the model of surgical tibia fracture the formation of connective tissue in the bone was studied. In the control animals the fibrous connective tissue determined by fibroblasts and occasional macrophages proliferating was formed between the bone fragments in 10 days after injury. Outwards from the fibrous structures the chondroblast foci were observed.


Figure 1. Zone of fracture with in 10 day after injury. Control group. Hematoxylen-eosin, 200[

Figure 2. Zone of fracture with in 10 day after injury. DENS group. Hematoxylen-eosin, 200[

Table I

The activity of the inflammatory response to DENS

Bone remodeling occurred both due to periosteal and endosteal ossification (Figure 1). In DENS group there was a more active proliferation of osteoblasts and microcirculation intensification (Figure 2). Computer morphometry showed 29% increasing of fibroblastic and osteoblastic cells content in regeneration area (P<0.05). It confirms the DENS ability to stimulate the proliferation of these cells. The positive effect of DENS on the regeneration of bone tissue was accompanied by its pronounced anti-inflammatory effect. This was judged by normalization of leukocyte reaction and blood acute phase reactants lowering - fibrinogen and C-reactive protein (Table I). As it can be seen from the data indicators of inflammatory activity after DENS exposure were significantly lower than in the control group at 10 days after injury and were approaching the level of intact animals. The processes of regulation of tissue homeostasis are under the control of complex regulatory mechanisms. 2, 3 The study and deep understanding of them is a prerequisite for pathogenesis studies and practical implementation of new methods of controlled regeneration.

Using various models of pathological processes in experimental animals we can evaluate the repairing, the ratio of systemic and local cellular reactions and their modification by various medical factors. In particular the mechanisms of recovery stimulation at the cellular, tissue and organ levels with magnetic laser exposure and medical ultrasound were established.4, 5 This study evaluated the impact of DENS on regenerative processes in tissues.

We found the increasing reparative processes of bone under the DENS influence, that we associate with increased proliferative activity of osteoblastic cells as well as increasing microcirculation. In the model of skin wound we did not find pronounced acceleration of epithelialization of the defect but revealed distinct trend of slowdown in the perifocal inflammatory reaction. These data correlate with immunotropic effects of DENS shown in previous studies.6

Conclusion

DENS stimulates the reparative processes in tissues after damage. The intensity of microcirculation increased and the activity of the inflammatory reaction in damage zone moderately decreased.

References

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2. Bazarny VV, Valamina IE, Selyanina ON, Tikhonina EA, Beresneva OY, Klein A et al. Immunomodulation by ribomunil of reparative processes in the skin of rats. Bull Eksp Biol Med 2007;143:660-2.
3. Bazarnyi VV, Krokhina NB, Isaikin AI, Tikhonina EA. Effect of granulocyte colony-stimulating factor on reparative osteogenesis. Patol Physiol Exp Ther 2008;26-7.
4. Bazarny VV, Valamina IE, Samoilov DS, Isaykin AI, Schekoldin PI. Correction mechanism of inflammatory and reparative processes in the skin with ultrasound. Vestnik of Uralsk. med.akadem. Science 2008;3:29-30.
5. Bazarny VV, Schekoldin PI, Krokhina NB, Isaykin AI, Tikhonina EA. Several cellular mechanisms of magnetic-influence on reparative osteogenesis. Vopr Curortiol Physiother Therap Phys Culture 2008;5:33-4.
6. Bazarnyj VV, Sheshenin AV, Isaykin AI, Vlasov AA Score immunotropic effects of dynamic electroneurostimulation. Russ Immunology J 2008;2:147-8.