Morphometric and structural changes in the rectus abdominis muscle of rats under conditions of experimental obesity and diabetes mellitus

Myroslav Kritsak; Oleh Slabyi; Tetiana Gargula; Oleh Yasinovskyi; Olena Levchyk; Oksana Balitska

Myroslav Kritsak Department of Surgery, I. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine
Oleh Slabyi Department of Operative Surgery and Clinical Anatomy, I. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine
Tetiana Gargula Department of Operative Surgery and Clinical Anatomy, I. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine
Oleh Yasinovskyi Department of Therapeutics and Family Medicine, I. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine
Olena Levchyk
Oksana Balitska Department of Pathophysiology, I. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine

Keywords: diabetic myopathies, obesity, muscle, skeletal, insulin resistance, muscular atrophy

Abstract

The modern metabolic paradigm considers skeletal muscles not only as an organ of locomotion but as a key metabolic unit responsible for the regulation of glucose homeostasis in the body. The aim of the work is to establish the morphofunctional features of changes in the rectus abdominis muscle of rats under conditions of 8-month modeling of alimentary obesity caused by a high-fat diet and subsequent induction of diabetes mellitus. The study was conducted on 30 sexually mature Wistar rats, divided into three groups of 10 individuals: a control group, a group with a high-fat diet, and a group with a diet and induced diabetes mellitus. Histological examination of the muscles of rats in the high-fat diet and diet with diabetes mellitus groups revealed pronounced signs of diabetic myopathy. In the alimentary obesity group, initial changes were observed in the form of unevenness in the caliber of muscle fibers and signs of intracellular lipid accumulation. In the diet and diabetes group, structural disorders became degenerative in nature, areas with pronounced myocyte atrophy, areas of fiber architectonics disturbance, sarcolemma fragmentation, and focal infiltration were visualized. The nuclear apparatus of myocytes in these groups showed signs of chromatin condensation and pyknosis, which indicates the activation of destructive processes. Additionally, a significant decrease in the density of the capillary network in the endomysium was recorded, which was accompanied by signs of endothelial dysfunction, creating conditions for chronic local energy deficiency of the tissue. The study allowed us to establish the complex nature of structural and functional changes in the rectus abdominis muscle under conditions of metabolic stress induced by a combination of a high-fat diet and type 2 diabetes.