ELECTRONIC-MICROSCOPIC CHANGES OF THE INTRAMURAL NERVOUS PLEXUS OF THE DUODENUM IN CONDITIONS OF CHRONIC STRESS

Abstract

The article presents a study of ultrastructural changes of neurons of the intramural nervous system (muscular- intestinal plexus) of the duodenum under chronic stress. The experiment was performed on 60 white adult male rats. The material was taken from the proximal and distal parts of the duodenum after 14, 28, 56 days of the experiment. For electron microscopic examination, pieces of the duodenum were fi xed in 2.5% glutaraldehyde solution for 4 hours, and then fi xed in 2% osmium tetroxide solution. First, semi-thin sections were made to detect the localization of nerve cells of the musculoskeletal plexus of the duodenum, staining them in 1% methylene blue solution or 0.1% toluidine blue solution. Ultrathin sections were made on an ultramicrotome Tesla BS-490A, the material was studied on an electron microscope TEM – 125 K («Selmi», Ukraine). After 14 days of chronic stress, there is signifi cant damage to the neurons of the musculoskeletal plexus of the duodenum due to reactive and edematous processes, accompanied by the development of ultrastructural changes and the death of some neurons. After 28-56 days of the experiment, edematous, dystrophic- destructive processes in nerve cells are further observed, but in some of them there are a number of compensatory- adaptive and reparative processes aimed at restoring impaired functions.