Análise comparativa dos efeitos morfofuncionais e ultraestruturais dos diabetes mellitus tipo 1 e diabetes mellitus tipo 2 no fígado de ratos

Abstract

Diabetes mellitus (DM) is a chronic metabolic disease characterized by persistent hyperglycemia, resulting from a deficiency in insulin secretion and/or resistance to its action. The global prevalence of DM is rapidly increasing, with alarming projections for the future. DM is associated with several serious complications such as blindness, kidney failure, myocardial infarction, stroke, and lower limb amputation. Despite sharing hyperglycemia as a common symptom, DM1 and DM2 differ in various aspects, including prevalence, origin, genetic factors, affected groups, age groups, diagnosis, progression, and treatment. These differences are primarily related to the opposite patterns of insulin secretion in these diseases. AFM (Atomic Force Microscopy) is a valuable tool for analyzing tissues affected by DM2, allowing for the assessment of mechanical, electrical, and viscoelastic properties of cells, as well as the generation of high-resolution topographical maps of cellular structures. However, there are few studies comparing morphological changes in tissues affected by DM1 and DM2 using AFM, especially in animals exposed to unbalanced diets. The study aimed to investigate latent metabolic defects and hepatic ultrastructural changes in different types of DM, comparing DM1 and DM2.The study was conducted on Wistar rats divided into groups according to maternal diet and the type of DM developed. The animals underwent a series of assessments, including glucose tolerance tests, gene expression analysis, histological evaluation of the liver, and AFM analysis. The results showed significant differences between DM1 and DM2 regarding body composition, glycemic profile, lipid profile, insulin resistance, hepatic gene expression, and hepatic morphology. DM1 was characterized by muscular and adipose atrophy, hypoinsulinemia, hyperglycemia, and insulin resistance, while DM2 exhibited central obesity, obesogenic sarcopenia, hyperinsulinemia, hyperglycemia, and insulin resistance.Histological analyses revealed differences in hepatic steatosis and fibrosis between the groups, with DM2 showing greater hepatic impairment. Furthermore, AFM demonstrated alterations in the mechanical and ultrastructural properties of hepatic cells in diabetic groups, with DM2 exhibiting more significant changes. The results highlight the metabolic, morphological, and functional differences between DM1 and DM2, attributed to the opposing patterns of insulinemia in these diseases. DM1 is characterized by insulin deficiency due to the destruction of β-pancreatic cells, while DM2 is associated with insulin resistance and excessive insulin production. Diet plays a fundamental role in inducing these different presentations of DM. This study contributes to a better understanding of the differences between DM1 and DM2, providing insights into the underlying mechanisms and emphasizing the importance of diet in the induction of these diseases. The findings may have implications for early detection and the development of specific therapeutic approaches for each type of DM.