Morphometric characteristics of structural reconstruction of duodenal muscle at postresection portal hypertension

Abstract

The aim of the work: using morphometrical methods to study the features of remodeling of the structures of duodenal musclе at postresection portal hypertension. Materials and Methods. The complex of morphological methods examined the duodenum of 45 sexuale mature white  male rats, which were divided into 3 groups. The group 1 consisted of 15 intact animals, group 2 – 15 rats, in which 31.5 % of the liver parenchyma was removed,  group 3 – 15 animals after resection of 58.1 % of liver parenchyma. Euthanasia of rats was carried out by bloodletting in conditions of thiopental anesthesia  1 month after from the beginning of the experiment. From the duodenum  histological medicines were made. The thickness of the circular  and longitudinal muscle layers, the diameters of smooth myocytes and their nuclei, the nuclear-cytoplasmic relations in these cells, the stromal-myocytal relations, and the relative volumes of damaged myocytes were measured. Quantitative indicators were processed statistically.

Results and Discussion. It was established that one month after resection of 31.5 % of liver parenchyma, morphometric indices were slightly changed. Removal of 58.1 % of liver parenchyma leads to the development of postresection portal hypertension. The morphometric parameters of the structures of the longitudinal and longitudinal layers of the muscle cover of the duodenum were manifested by altered ones. The thickness of the circular layer of the muscle membrane a month after the resection of 58.1 % of the liver parenchyma statistically significantly decreased by 5.0 %, the diameter of myocytes – by 8.7 %, the nuclear-cytoplasmic relation of them increased by 42.8 %, stromally-miocytal relation – by 21.0 %, relative the number of damaged myocytes – by 15.9 times. Quantitative morphological indices of the structures of the longitudinal layer of the duodenal muscle a month after the resection of 58.1% of the liver parenchyma changed in a similar manner, but the degree of their expression was smaller compared with the structures of the circular layer. Thus, the diameter of myocytes in the given experimental conditions was reduced by only 0.92 %, the diameter of the nuclei increased by 7.1 % (p <0.05), nuclear-cytoplasmic relations – by 16.8 % (p <0.001), stromally -miocytal relations – by 14.7 %, relative volume of damaged myocytes – by 9.3 times.

The results of the study suggest that the removal of large volumes of liver parenchyma leads to postresection portal hypertension and pronounced morphological rearrangement (remodeling) of the structures of the circular and longitudinal layers of the duodenal muscle, characterized by disproportional uneven changes in the morphometric parameters of smooth myocytes, their nuclei, violations of nuclear-cytolazmatic relations in these cells, atrophy, growth of stromal structures and relative volumes of damaged myocytes in the muscle, which may be complicated by the dysfunction of the  organ.