Morphological analysis of rectus abdominis muscle and urethral striated muscle of long-term mild diabetes pregnant rats submitted to aquatic exercise

Author(s)

Bruna Bologna Catinelli

• Document type: Master's Dissertation
• Press: Botucatu. 2020-03-11.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina. Botucatu
• Defense date: 2020-02-17
• Advisor: Marilza Vieira Cunha Rudge; Patrícia de Souza Rossignoli; Angélica Mércia Pascon Barbosa

Abstract

Introduction: Gestational Diabetes Mellitus (DMG) is a common complication in pregnancy and recent studies have shown that diabetes causes failure to maintain muscle health and function, named Diabetic Myopathy. Studies evidenced important morphological changes in the rectus abdominis muscle and urethral striated muscle of diabetic pregnant rats. Thus, it is necessary to evaluate the impact of the aquatic exercise program for regeneration of rectus abdominis muscle and urethral striated muscle of long-term mild diabetes pregnant rats for clinical application in humans. Objective: To analyze the effect of aquatic exercise on rectus abdominis muscle and urethral striated muscle of long-term mild diabetes pregnant rats. Methods: At the first day of birth Wistar newborns received Streptozotocin 100 mg/kg, subcutaneously. At 90 days of life, a blood glucose measurement was performed, considering diabetes glycemic level between 120-300 mg / dL and non-diabetes glycemic level <120 mg / dL. Mating began, and on gestational day zero the animals were distributed in non-diabetic sedentary (NDS), non-diabetic exercised (NDE), sedentary diabetic (DS) and exercised diabetic (DE) groups. The aquatic exercise started on gestational day zero of and performed during the whole pregnancy (60 minutes/day, 6 days/week). On the 21st day of pregnancy, the rectus abdominis muscle and urethral striated muscle were obtained to morphological analysis (Hematoxylin & Eosin, Picrossirius Red, Masson's Trichrome and Transmission Electron Microscopy) and morphometric analysis of the muscle fibers and the extracellular matrix. Significance limit <0.05 was considered. Results: Our results showed decreased muscle area in the rectus abdominis muscle in DS group (p<0.01), and the DE group did not increase this parameter, that is, the exercise protocol used did not reverse this alteration. The ultrastructural analysis showed sarcomere rupture in both diabetic groups and an increase in intermiofibrillar mitochondria in both exercised groups. Regarding the urethral striated muscle, decreased blood vessels area was found in the DS groups compared to the NDS (p <0.0001), NDE compared to the NDS (p <0.0001) and DE compared to the DS and NDE (p <0.0001). The ultrastructural analysis showed sarcomere disruption areas in the DS group, which was not observed in DE group. Conclusion: Long-term mild diabetes resulted in structural and ultrastructural changes in the rectus abdominis muscle and the exercise protocol did not reverse these changes. Although no morphometric changes were found in the urethral striated muscle, the decrease in blood vessel area resulting from moderate diabetes and exercise can cause vascular changes with the potential to directly impact on skeletal muscle. More studies need to be carried out in order to develop the most efficient exercise protocol for the treatment of diabetic myopathy. (AU)

• FAPESP's process: 18/03361-8 - Morphological analysis of rectus abdominis and urethral striated muscles of diabetic pregnant rats submitted to exercise in aquatic environment
• Grantee: Bruna Bologna Catinelli
• Support Opportunities: Scholarships in Brazil - Master