Micro- and ultrastructural organization of the common bile duct wall during four-week opioid effect in the experiment

Abstract

Background. The widespread use of narcotic agents in clinical practice to obtain analgesic and anti-inflammatory effects requires a comprehensive morphological study of the structural organization of organs during the effect of opioids. Despite the urgency of the problem, only a few works have been devoted to the effect of opioids on the morphological state of the bile ducts. Objective: to establish the features of changes in the micro- and ultrastructural organization of the common bile duct during the four-week opioid administration in the experiment. Methods. We used histological, electron microscopic, morphometric, and statistical methods. A computer program ImageJ was used to measure the diameter of the lumen and thickness of the common bile duct wall. Results. After 4 weeks of nalbuphine administration, the common bile duct of experimental animals is dilated, its wall is disorganized, the layer of epitheliocytes (cholangiocytes) of the duct mucous membrane is deformed, often without clear contours. The cytoplasm of cholangiocytes is enlightened, mitochondria have the damaged crystals, a granular endoplasmic reticulum is destructured, the nuclei of epithelial cells lost their characteristic columnar shape, became rounded, contained condensed chromatin along the nuclear membrane, found nuclei in a state of apoptosis and karyopyknosis. Own plate of the mucous membrane in the common bile duct is fluffy and swollen, the glands are destructured and shifted in the direction of the epithelial layer. The bundles of smooth myocytes of the muscular membrane are stratified and separated by wide layers of connective tissue. Mitochondria of myocytes are swollen, cristae of many mitochondria are homogenized; in most of myocytes, there are revealed the unstructured sites of cytoplasm in a condition of small vacuole dystrophy. The arterioles of the common bile duct wall are dilated, their wall is thickened; in lumens, there was a formation of wall thrombi, the venules are expanded, the walls of venules are thinned. Conclusion. Four-week administration of the Nalbuphine opioid leads to profound changes in the micro- and ultrastructure of the common bile duct wall in experimental white rats. There is the dilatation of the common bile duct, thickening of its wall, the signs of exudative-proliferative inflammatory process predominate in the mucous membrane, there are developed the vacuolar dystrophy of myocytes in the muscular membrane of the common bile duct and fibro-sclerotic changes in the connective tissue layers.