The dissertation is devoted to the study of morphofunctional changes of the adrenal medulla during burn. The results of histological and electron microscopic studies are confirmed the dynamics of the development of morphofunctional changes of the adrenal medulla, gland microcirculatory changes, stress response and dystrophic changes. The main morphological sings of microcirculation changes were blood stasis, severe dilatation of hemocapillaries and sinusoidal venules; the ultrastructural changes were edema of the endothelial cell cytoplasm, loss of organelles and increased thickness of peripheral zone of the endothelium. The endothelium integrity in hemocapillars and venules was not disturbed on 7th day, but in the next days were registered local hemorrhage, diapedesis of erythrocytes into paravasal space and tissue interstitium of the adrenal medulla, entrance of necrosis products in the lumen of microvessels. Analysis of the morphometric data dynamics is showed a stable vasodilation in the period in 3–21 days and a tendency to decrease of the microvessels lumen and restore microcirculation to 30 days. The increased thickness of the peripheral zone of the endothelium was detected on the 1st day after burn, and after 14th day the endothelial thinning is associated with restorative processes and morphofunctional disturbances.
The results of electron microscopy were demonstrated partial epinephrocyte degranulation and redistribution of hormonal granules (granule diameter decreased by 30%) in the first 3 days which was assessed as a manifestation of stress response in response to injury. On 7–14 day an increased density and diameter of hormonal granules was indicated as adaptive morphofunctional changes. Dystrophic disorders were also found, which included endocrinocytes cytoplasm edema, mitochondrial edema and their fragmentation, destruction of endoplasmic reticulum cisterns, karyopyknosis in the 21–30 day. Ultrastructural changes of nerve fibers were manifested in edema of myelin sheath and destruction of axial cylinders.
Manitol and quercetin has had a positive effect on the morphofunctional changes of the adrenal medulla, especially in the acute period of burn injury. At the ultrastructural level less stasis and dilatation of hemocapillaries and venous sinusoids, integrity of microvessel endothelium, suppressed penetration of the cellular debris into their lumen were found. Inhibition of dystrophic changes of epinephrocytes and norepinephrocytes, fibroblasts and endothelial cells, stabilization of the hormone-producing activity of epinephrocytes have been established, i.e. suppression of stress response and activation of recovery. At the end of the experiment, we have concluded two independent processes – the elimination of dead cells and the initiation of recovery processes. The first include the destruction and elimination of the death cells (endocrinocytes, fibroblasts, endothelial cells) by macrophages phagocytosis; the second about decrease of dystrophic changes was evidenced in ultrastructural and morphometric parameters of mitochondria, endoplasmic reticulum and the synthesis of epinephrocyte granules. Reduction of mitochondrial edema and their fragmentation has been evaluated as a cytoprotective response of endocrinocytes to injury, especially with the combined application of mannitol and quercetin. Another sings of cytoprotective action was the inhibition of the development of structural disorders of nerve fibers and neurolemmocytes.
The results of the biochemical studies have been showed the development of interdependent changes: increasing of products of lipid and protein peroxidation and reduction the indicators of antioxidant system. Burn injury was characterized a significant increase in TBА-active products, diene conjugates and carboxyl groups. These metabolites peak was set on the 14th day and not recovered to the control parameters. A pool of free SH-groups at burn shock was depleted, and the recovery tendency got started after 21st day. The DT-diaphorase activity was less than the control values in the first 7 days after burn. The recovery of the antioxidant system was noted from the 14th day after the burn and was not restored to its original values during experimental terms. Interdependent development of dystrophic changes and oxidative stress after burn was summarized as conclusion of experimental studies. Pharmacocorrection was influenced in a significant reduction of protein and lipid peroxidation and the recovery of the pool of free SH-groups in the period on 21–30 days, and the activity of DT-diaphorase on day 3 after burn. The results of biochemical studies have been provided important information for understanding the regression of morphological changes in the adrenal medulla of, which determines the actuality of our study.
