Ultrastructural reorganization of the constituent components of the rat periodontium under conditions of chronic opioid exposure

Abstract

Opioid addiction has acquired the characteristics of an epidemic in recent years and is a serious problem in modern medicine. In users of narcotic substances, a significant prevalence of diseases of the oral cavity and periodontal tissues is noted in comparison with the general population. The aim of the work was to investigate the ultrastructural organization of the periodontal tissues of rats at the end of the fourteenth week of the experimental opioid effect. The animals were administered intramuscularly, daily, once, the opioid analgesic nalbuphine (pharmacotherapeutic group: analgesics, opioids, morphinan derivatives) in increasing doses for 14 weeks: 1-2 weeks – 0.212 mg/kg, 3-4 weeks – 0.225 mg/kg, 5-6 weeks – 0.252 mg/kg, 7-8 weeks – 0.260 mg/kg, 9-10 weeks – 0.283 mg/kg; 11-12 – 0.300 mg/kg, 13-14 weeks – 0.450 mg/kg. At the end of the fourteenth week of opioid exposure, ultrastructural changes in the epithelium of the mucous membrane of the gums, periodontium, and hemomicrovessels with the development of decompensation and pronounced dystrophic-destructive changes were established. With the long-term effect of an opioid analgesic, signs of karyorrhexis, segregation of nucleoli, spongiosis, apoptosis, violation of the integrity of intercellular contacts, as well as vacuole-like formations, which were a manifestation of focal necrosis of epitheliocytes, were revealed. The development of necrotic changes was caused by significant damage and destruction of organelles, as well as fragmentation or lysis of bundles of tonofilaments. The intercellular spaces were mostly expanded and uneven, which was caused by edematous phenomena. Fragmentation and destruction of periodontal collagen fibers, destructive changes in fibrocytes and fibroblasts were found in the periodontium. The translucency of the amorphous component of the intercellular substance of the connective tissue was determined. The ultrastructural reorganization of the cellular components of the periodontium was caused by vascular disorders of a systemic nature, which were manifested by the phenomena of dilatation, hemoptysis, sludge phenomenon, dystrophic changes in the endotheliocytes of hemocapillaries and venules, and the progression of sclerotic changes, which significantly disturbed the trophism of the periodontal tissues of rats.