Morphological evaluation of the effects of ursodeoxycholic acid on muscular layer of the gallbladder wall of the mice

Abstract

Background. Significant prevalence and the possibility of transformation into organic pathology determine the relevance of functional disorders of the gallbladder and sphincter of Oddi in children. The proposed hypothesis is that the increased differentiation of fibroblasts into the smooth muscle cells of the gallbladder wall in the experimental model of mice occurs under the influence of ursodeoxycholic acid. Objective: to determine the histo-ultrastructural changes of cells of the muscular wall of the gallbladder wall of experimental mice under the action of ursodeoxycholic acid. Methods. By the method of simple randomization, mice were divided into 2 groups: experimental group (n = 17) - animals that were received ursodeoxycholic acid at a dose of 100.0 mg/kg and control group (n = 13) - intact (distilled water). Gallbladder morphological examination was performed using light and electron microscopy methods. Results. Impact of ursodeoxycholic acid on the gallbladder muscular layer characterized by moderate hypertrophy of the gallbladder smooth muscle myocytes that contain metabolically active pale nuclei and prominent nucleoli. After the ursodeoxycholic acid administration an increase in the content and activity of the elements of the contractile and energy apparatus of leiomyocytes were found. In addition, ursodeoxycholic acid administration led to an increase in the number of caveolae and micropinocytic vesicles near the cell membrane of smooth muscle cells. Analysis of the components of the interstitium of the mice gallbladder muscular layer of the experimental group revealed the nuclear activity of fibroblasts due to the decondensation of chromatin. Also in the experimental group was characterized by the presence of immature collagen fibrils along with normal striated fibers that was a sign of the rearrangement of the endomysium structure. Conclusion. The effect of ursodeoxycholic acid on the muscular membrane of the gallbladder wall of mice of the experimental group is morphologically manifested by signs of moderate hypertrophy of smooth myocytes, activation of their intracellular transport and increased activity of interstitial fibroblasts.