Our article aims to study the pathomorphological manifestations of angio- and neuroretinopathies as a result of chronic exposure to therapeutic doses of opioid analgesics and the possibility of correction of these changes with the help of pentoxifylline at early stages of destructive changes in the layers of the retina. This goal was achieved by using a histological retinal imaging technique. Histological preparations were prepared according to the conventional method using the dyes hematoxylin, eosin, and (azan) in compliance with the method of Heidenhain.The results of the study in the future will allow us to form a pathomorphological base, which can be used for comparative characterization of the dynamics of the growth of pathomorphological changes in the retinal layers during the short and long term exposure to low doses of opioids and the correction of these changes with pentoxifylline at the early and late stages of opioid exposure. The above will further enable us to establish the most optimal time framework for which there is a characteristic set of pathomorphological manifestations of the initial phenomena of angioneuroretinopathy in the layers of the retina, which is best exposed to corrective effects.

The work, presented below, aimed at studying the dynamics of structural disorganization of morphological components of the articular cartilage at ultrastructural level in subchronic and chronic periods of experimental opioid chondrodystrophy. The purpose was achieved by ultrastructural visualization of the components of the articular cartilage. Generally accepted conventional methods were used for obtaining microstructural material.The results of the study will form pathomorphological basis, which can be applied for the development of diagnostic criteria for lesions of the articular cartilage at different stages of opioid exposure. Furthermore, pathomorphological findings will form the basis for effective medical handling of opioid chondrodystrophy of the articular cartilage and its consequences.

The following work is aimed at studying the features of the restructuring of the structural components of periodontal tissues under the conditions of a six-week experimental effect of an opioid analgesic at the ultrastructural level. Destructive changes were found in all cellular components of the mucous membrane of the gums, the periodontium and in the links of the microcirculatory bed. The ultrastructural manifestations in periodontal tissues that occur with the action of an opioid analgesic for six weeks may serve as a morphological basis for further study of the dynamics of submicroscopic changes in the later stages of opioid exposure in the experiment.

This paper presents the results of an electron microscopic study of the cellular components of periodontal tissues with experimental exposure to opioids for 28 days. It has been established that degenerative-destructive changes in all structural components of the periodontium occur during the four-week action of the opioid analgesic. The researches carried out in the future can serve for the differential characterization of the destructive manifestations arising during the short and long-term action of opioid analgesics at the ultrastructural level.

The work, presented below, compares pathomorphological changes of the articular cartilage in the distal epiphysis of the femur and proximal epiphyses of the tibia at the end of the 56th day in rats after two - week opioid withdrawal at the micro- and ultrastructural levels. The goal was achieved by micro- and ultrastructural visualization of the components of the articular cartilage. Specimen preparation for electron and light microscopy was done according to the generally accepted methods.The results of this study will form the basis for developing a comprehensive therapeutical approach in management of lesions of structural components of the articular cartilage in opioid chondrodystrophy.