Posthypoxic Changes in Rat Offspring under the Intestinal Wall Transformation

Abstract

The aim of research is to study posthypoxic transformation of the colon wall using light and electron microscopy in an experimental model of rat offspring.
 Materials and methods. Chronic hypobaric hypoxia at different stages of pregnancy was simulated experimentally in 24 female white mongrel rats using a vacuum flow chamber with a rise to a height of 5000 m at a speed of 25 m/sec for 40 minutes. After delivery, the offspring were examined, subjected to hexenal anesthesia, and then removed from the experiment using decapitation. For light microscopy, resected sections of the small intestine and colon were stained with hematoxylin-eosin, and studied on Topic (Belgium, 2000) and Bio Blue (the Netherlands, 2013). Electron microscopic analysis was performed in a Morgagni 268D transmission electron microscope (FEI, USA).
 Results. Chronic hypoxia, simulated in the first trimester of pregnancy, led to significant changes in the intestinal mucosa in combination with the growth of the connective tissue component in the muscle layer. The risk of developing dynamic intestinal obstruction occurred in the offspring of all groups, this was supported by an increase in the fibrous tissue of the intestinal wall. Pronounced changes in the microcirculatory bed were detected in animals of groups II and III, as they were predisposed to develop pre-ulcer and ulcerative defects in the wall of the small intestine. At the submicroscopic level, it was detected that both adaptive and destructive processes occurred in the wall ultrastructure of the descending colon of the rat offspring after hypoxic exposure in the prenatal period in animals of all experimental groups. In the microcirculatory bed, there was an increased venous congestion, with the most pronounced changes observed in the third trimester.
 Conclusion. Thus, the study of hypoxia in the experiment allows investigating more about all the mechanisms of the pathological process and to translate theoretical knowledge into practical medicine.

Experimental modeling of necrotic enterocolitis: A review

“…Такие изменения возникают на фоне энтеральной нагрузки. Помимо этого, данный вариант механической окклюзии возможен у взрослых или молодых животных (у новорожденных крысят дифференцировка тканей низкая, размер сосудов слишком мал для прецизионной работы с ними), что также устраняет важный аспект незрелости организма [4,5,8].…”

“…Помимо этого, важную роль в развитии НЭК новорожденного играет ранняя и неадекватная энтеральная нагрузка преимущественно искусственными молочными смесями, а также инфицирование его организма патогенными микроорганизмами [4]. Учитывая сложный патогенез развития данного заболевания, прицельное воздействие на его звенья является важной задачей хирургов и неонатологов [5]. Несмотря на значительные успехи в современной клинической медицине, смертность от НЭК остается достаточно высокой и занимает лидирующие позиции среди новорожденных.…”