Reversal of diabetic-induced myopathy by swimming exercise in pregnant rats: a translational intervention study.

Gestational diabetes mellitus (GDM) plus rectus abdominis muscle (RAM) myopathy predicts long-term urinary incontinence (UI). Atrophic and stiff RAM are characteristics of diabetes-induced myopathy (DiM) in pregnant rats. This study aimed to determine whether swimming exercise (SE) has a therapeutic effect in mild hyperglycemic pregnant rats model. We hypothesized that SE training might help to reverse RAM DiM. Mild hyperglycemic pregnant rats model was obtained by a unique subcutaneous injection of 100 mg/kg streptozotocin (diabetic group) or citrate buffer (non-diabetic group) on the first day of life in Wistar female newborns. At 90 days of life, the rats are mated and randomly allocated to remain sedentary or subjected to a SE protocol. The SE protocol started at gestational day 0 and consisted of 60 min/day for 6 days/week in a period of 20 days in a swim tunnel. On day 21, rats were sacrificed, and RAM was collected and studied by picrosirius red, immunohistochemistry, and transmission electron microscopy. The SE protocol increased the fiber area and diameter, and the slow-twitch and fast-twitch fiber area and diameter in the diabetic exercised group, a finding was also seen in control sedentary animals. There was a decreased type I collagen but not type III collagen area and showed a similar type I/type III ratio compared with the control sedentary group. In conclusion, SE during pregnancy reversed the RAM DiM in pregnant rats. These findings may be a potential protocol to consider in patients with RAM damage caused by GDM.

Deleterious effects of gestational diabetes mellitus on the characteristics of the rectus abdominis muscle associated with pregnancy-specific urinary incontinence.

AIMS: To evaluate the effects of gestational diabetes mellitus (GDM) on the structural characteristics of the rectus abdominis muscle (RAM) and its indirect effects on pregnancy-specific urinary incontinence (PSUI). METHODS: A total of 92 pregnant women were divided into four groups, according to their clinical conditions: non-GDM continent, non-GDM associated PSUI, GDM continent and GDM associated PSUI. The muscle morphometry (histochemistry and immunohistochemistry) for the fiber types and collagen fiber distribution, the ultrastructural analysis (transmission electron microscopy), the protein expression of fiber types and calcium signaling (Western blotting), and the content of types I and III collagen fiber (ELISA) in RAM collected at delivery were assessed. RESULTS: The GDM groups presented a significantly increased number of slow fibers and slow-twitch oxidative fiber expression; decreased fiber area, number of fast fibers, and area of collagen; an increase in central nuclei; ultrastructural alterations with focal lesion areas such as myeloid structures, sarcomere disorganization, and mitochondrial alteration. The PSUI groups presented a considerable decrease in types I and III collagen contents and the localization of collagen fiber. CONCLUSIONS: Our data reveal that GDM causes morphological, biochemical and physiological changes in the RAM, and this might predispose women to PSUI.

Subcutaneous tissue reaction and cytotoxicity of polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene blends associated with natural polymers.

Cytotoxicity and subcutaneous tissue reaction of innovative blends composed by polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene associated with natural polymers (natural rubber and native starch) forming membranes were evaluated, aiming its applications associated with bone regeneration. Cytotoxicity was evaluated in mouse fibroblasts culture cells (NIH3T3) using trypan blue staining. Tissue response was in vivo evaluated by subcutaneous implantation of materials in rats, taking into account the presence of necrosis and connective tissue capsule around implanted materials after 7, 14, 21, 28, 35, 60, and 100 days of surgery. The pattern of inflammation was evaluated by histomorphometry of the inflammatory cells. Chemical and morphological changes of implanted materials after 60 and 100 days were evaluated by Fourier transform infrared (FTIR) absorption spectroscopy and scanning electron microscopy (SEM) images. Cytotoxicity tests indicated a good tolerance of the cells to the biomaterial. The in vivo tissue response of all studied materials showed normal inflammatory pattern, characterized by a reduction of polymorphonuclear leukocytes and an increase in mononuclear leukocytes over the time (p < 0.05 Kruskal-Wallis). On day 60, microscopic analysis showed regression of the chronic inflammatory process around all materials. FTIR showed no changes in chemical composition of materials due to implantation, whereas SEM demonstrated the delivery of starch in the medium. Therefore, the results of the tests performed in vitro and in vivo show that the innovative blends can further be used as biomaterials.