Experimental study of action exogenous no on the wound process

A study carried out in Sechenov Moscow Medical Academy on 170 white rats included several sets of experiments on the models:
1) conditionally aseptic fully layered planar wound with area 300 mm2,
2) the same infected with Staphylococcus aureus of purulent wound area and
3) linear skin wound with the length of 3 cm.

To 2, 3 and 4 days in the experimental groups of the I and II series the wound surface also of the edge of wound finished during 60 sec, and in the III series – during 15, 30 and 60 sec by the NO- containing gas flow (NO -CGF), generated by apparatus “PLASON” (concentration NO – 500 ppm). In the control of wound they blew out by air at the same temperature. To 4, 7, 10, 14 and 21th days on 2-3 animals derived from the experience, selected biomatherial of the cloths of the wounds, which were studied by histological and histochemical methods, using paintings with hematoxylin and with eosin, Van- Gieson`s picrofuchsin, by toluidine blue to proteoglycan, Gomori`s silver, PAS- reaction to glycogen and glycoproteins, Brashe`s reaction to RNA and by Feulgen`s on DNA, and electron-microscopic examination also was conducted. Remaining rats left to the complete healing of wounds, planimetry of wounds was carried out every 3 days in them, data were processed statistically

IN the I set of experiments for the development the influences of NOx- therapy for the preventive maintenance of the wound complications of the rule of asepsis intentionally were not observed. In the control group in 42% of animals to 3 and 5 days appeared the signs of purulent inflammation. In the experimental groups these complications were absent. A planimetric study showed that in the experimental groups the area of wounds was decreased considerably more rapid than in the control (Fig. 1A). The average period of the complete healing of wounds in the test decreased for 7,5 days, the index of the acceleration of healing composed 24,6%.
Histological, histochemical and electron-microscopic examinations showed that from 4 days in the experience is noted the significant acceleration of the wound process, which to this period, in contrast to the control, already passes from the inflammatory to the reparative phase. In the bottom of wound is well developed granulating cloth (in the control – only centers in inflammatory- infiltrated cellulose tissue), are expressed the proliferation of the fibroblasts (many mitoses), the new formation of capillaries, fibrillogenese of collagen, the accumulation of proteoglycans and PAS- positive glycoproteines (Fig. 2). Fibroblasts are characterized by the increased content RNA in the cytoplasm, and it is ultrastructural – by signs of the increased synthesis of protein, by well developed granular endoplasmic reticulum and by Golgi` complex (Fig. 3). Considerably more strongly is expressed in the experience macrophage reaction, including the phagocytic activity of macrophages. This is manifested in the increased content of phagosomas and lysosome in their cytoplasm. The phagocytosis of microbes by macrophages and by neutrophils is intensified, the colonies of bacteria on superficial wound are revealed only in control animals.

Especially should be noted differences in the microcirculatory reaction. In the experience the vasodilation of the newly formed capillaries is revealed; however, such phenomena as the destruction of endothelium, agglutination of erythrocytes, aggregation of thrombocytes, micro-thrombosis, adhesion and increased migration of neutrophils are expressed considerably weaker than in the control, and in the succeeding periods they disappear. Granulating cloth rapidly ripens in 7 – 10 days in the experience, while in 14 days it undergoes fibrocicatricial transformation, the reduction of capillaries and fibroblasts occurs, the large fields of collagenic fibrils appear, increases boundary epithelisation and differentiation of the epithelium (Fig. 4). To 21 days in the experience, in contrast to the control, the epithelization in the majority of animals concludes, begins remodulation of scar tissue, inflammatory manifestations are absent.

IN the II set of experiments, where the wounds were infected with staphylococcus, their area in the experience also was decreased more rapidly than in the control (Fig. 1B). The average period of the complete healing of wounds was accelerated by 31,6%. Morphological study in the control group to the 4th day revealed the sharply pronounced and prolong signs of microcirculatory disturbances, neutrophilic infiltration, edema, vasculita, the formation of primary and second necroses, micro-abscess, the significant infection of wounds, braking the phagocytosis of microbes and necrotic detritus, inhibition of macrophage reaction, proliferation of fibroblasts, increase in the capillaries, ripening of granulating cloth and epithelisation. In the experience all these signs were expressed considerably more weakly and more rapidly they disappeared. Granulating cloth was developed from the 4th day, and from the 14th day, in contrast to the control, its fibrosis formation occurred, contraction began epithelisation.