File
A. M. P. Barbosa1,2, B. Bologna Catinelli1, A. M. Carr1, K. S. Suyama2, G. B. Rabadan2, L. M. Nascimento2, M. A. Spadella3, S. L. Felisbino4, M. Vieira Cunha Rudge1, A.J. Bimbatti1, C. B. Prudencio1, P. S. Rossignoli2
1Botucatu Medical School (FMB), São Paulo State University (UNESP), Department of Gynecology and Obstetrics, Botucatu, Brazil, 2School of Philosophy and Sciences, São Paulo State University (UNESP), Department of Physiotherapy and Occupational Therapy, Marilia, Brazil, 3Marília Medical School (Famema), Marilia, Brazil, 4São Paulo State University (Unesp), Institute of Biosciences, Department of Morphology, Botucatu, Brazil
Background: Experimental study showed fiber type changes in the rectus abdominis of long-term mild STZ-induced diabetes pregnant rats.
Purpose: Swim exercise is effective on prevention and treatment of GDM. Our hypotesis was that swim exercise would be capable of improve the fiber type changes in skeletal muscle. The aim of the study was evaluate the impact of the aquatic exercise in the rectus abdominis morphology in diabetic pregnant rats.
Methods: This is a multicenter, basic sciences/translational study. 1st day of life, Wistar female rats received Streptozotocin at dose of 100 mg/kg, subcutaneously. 90 days of age each four females were mated overnight with one male rat for the maximum period of 15 days. The presence of spermatozoa in the vaginal smear was considered gestational day 0. The animals that presented glycemic level between 120-300 mg/dL and <120 mg/dL were included in the experimental groups: Control – Sedentary non-diabetic (C), Control – Exercised non-diabetic (Cex), Diabetic – Sedentary (D) and Diabetic – Exercised (Dex). The Cex and Dex groups started the swim exercise protocol on gestational day 0 until gestational day 20 (60 minutes/day, 6 days/week). On gestational day 21 the lower third of rectus abdominis muscle were obtained to immunoistochemical analysis. Immunoistochemical analysis was used to stain fast and slow fiber type (2 samples/group) and images from 7 sections/animal were obtained and analyzed using cellSens Standard software. The fast and slow fibers total area were quantified, as well as area and diameter of each fiber.
Results: The lower third of the rectus abdominis muscle showed higher proportion of fast fibers compared to slow fibers. There was no difference between groups in fast and slow fibers total area. However, the analysis of each fiber type showed reduction of the area and diameter of fast fibers in D group compared to C group (p<0.05) and increased area and diameter of slow fibers in D group compared to C group (p<0.0001). Regarding the effect of exercise over these changes, the results showed that swim exercise increased area and diameter of fast fibers in Dex group compared to D group (p<0.05 and p<0.001, respectively). There was no difference in the area and diameter of slow fibers in Dex group compared to other groups, but Cex group showed increased area and diameter of slow fibers compared to C group (p<0.0001).
Conclusion(s): We concluded that swim exercise improved the rectus abdominis muscle fiber type changes in lon-term mild STZ-induced diabetes pregnant rats. The analysis is currently running to increase the sample size and confirm the findings.
Implications: The results showed changes in the proportion of fiber type in the RAM of pregnant rats caused by long-term mild diabetes. Futhermore, swim exercise was capable to improve this change through the increase in area and diameter of fast fibers, which is the most prevalente fiber type in the lower third of rectus abdominis muscle. Our hypotesis is that the improvement of muscle fiber type may contribute to the improvement in muscle function as well. The next steps should be the translational to human adding exercise and functional measurements.
Funding, acknowledgements: This work was supported by grant #2016/01743-5 and fellowship grant (2018/03361-8), both from São Paulo Research Foundation (FAPESP)/Brazil.
Keywords: Animal Study, Pathophysiology, Physiology
Topic: Disability & rehabilitation
Did this work require ethics approval? Yes
Institution: São Paulo State University (UNESP), Marilia, São Paulo State, Brazil
Committee: on Animal Use of School of Philosophy and Sciences
Ethics number: CEUA nº 007/2016
All authors, affiliations and abstracts have been published as submitted.
