Efeito do exercício aeróbio moderado em parâmetros bioquímicos e morfológicos causados pela nefropatia diabética em ratos

Diabetes Mellitus (DM) is a chronic condition that occurs when the body does not or can not efficiently use insulin and is marked by metabolic abnormalities and chronic complications. Currently, regular exercise, combined with diet and insulin therapy, has been considered one of the main approaches in the treatment of DM, whereas sedentary lifestyle presents itself as a predictor of complications and mortality. Recent studies have reported that physical exercise is capable of slowing the progression of kidney disease. However, most of the studies verified renal changes in DM only in the long term. In addition, knowledge about the effects of physical exercise on diabetic nephropathy is still scarce. This work aims to investigate the effect of moderate aerobic exercise on the morphofunctional and biochemical aspects of renal tissue in diabetic rats. Male Wistar rats were divided into the following groups (n = 12 / group): sedentary control (CS), trained control (CT), sedentary diabetic (DS), diabetic trained (DT) and diabetic Previously trained (DTP). DM was induced by streptozotocin (40mg / kg, i.p.). Soon after the confirmation of diabetes, the exercise program consisted of six weeks of swimming (3 days / week and 30 minutes / day) for the CT and DT groups. The DTP group underwent four weeks of previous exercise in relation to the beginning of the training of the other trained groups. Blood samples were collected for biochemical analysis (blood glucose, creatinine and albumin). The kidneys were collected for the histopathological analysis of renal parenchymal integrity (Hematoxylin and Eosin), formation of fibrotic tissue (Picrosirius rer). The animals in the diabetic group had a higher glycemic index when compared to the control groups (p <0.001). There was a significant reduction in trained diabetic groups (p <0.01). Creatinine was increased in all groups when compared to control (p <0.05). Albumin, as well as weight, were decreased in the diabetic groups, compared to the control group (p <0.05). The DM had renal hypertrophy in the diabetic groups, compared to the control groups (p <0.05), but there was a significant decrease in the animals with trained groups (p <0.01). A smaller decrease in the number of glomeruli and In the diabetic groups, when compared to the control groups (p <0.05). And exercise was efficient in reducing glomerular fibrosis and tubular fibrosis. The results show that the application of moderate aerobic exercise in animals of an experimental model type 1 diabetes was able to prevent and / or treat kidney damage caused by the disease.Diabetes Mellitus (DM) é uma condição crônica que acontece quando o corpo não produz ou não consegue utilizar de forma eficiente à insulina e é marcada por anormalidades metabólicas e complicações crônicas. Atualmente a prática regular de exercício, aliada à dieta e insulinoterapia, tem sido considerada uma das principais abordagens no tratamento do DM, enquanto que o sedentarismo se apresenta como preditor de complicações e mortalidade. Estudos recentes têm relatado que o exercício físico é capaz de retardar a progressão da doença renal. Entretanto, a maior parte dos estudos verificaram alterações renais no DM somente em longo prazo. Além disso, o conhecimento sobre os efeitos do exercício físico na nefropatia diabética ainda é escasso. Este trabalho visa investigar o efeito do exercício aeróbio moderado sobre os aspectos morfofuncionais e bioquímicos tecido renal de ratos diabéticos. Ratos da linhagem Wistar, machos, 30 dias de idade, foram divididos nos seguintes grupos (n=12/ grupo): controle sedentário (CS), controle treinado (CT), diabético sedentário (DS), diabético treinado (DT) e diabético treinado previamente (DTP). O DM foi induzido por estreptozotocina (40mg/kg, i.p.). Logo após a confirmação do diabetes, teve início o programa de exercício, que consistiu em seis semanas de natação (3dias/semana e 30min/dia) para os grupos CT e DT. O grupo DTP foi submetido a quatro semanas de exercício prévio em relação ao início do treinamento dos demais grupos treinados. Foi feita a coleta de sangue para análise bioquímica (glicemia, dosagem de creatinina e albumina). Os rins foram coletados para análise histopatológica da integridade do parênquima renal (Hematoxilina e Eosina), formação de tecido fibrótico (Picrosirius rer). Os animais do grupo diabético tiveram índice glicêmico maior, quando comparados aos grupos controles (p<0,001). Houve uma redução significativa nos grupos diabéticos treinados (p<0,01). A creatinina foi aumentada em todos os grupos, quando comparados ao controle (p<0,05). A albumina, assim como o peso foram diminuídos nos grupos diabéticos, comparado com o grupo controle (p<0,05). O DM acarretou em uma hipertrofia renal nos grupos diabéticos, comparado com os grupos controle (p<0,05), porém houve diminuição significativa nos animais com grupos treinados (p<0,01) Foi observado uma menor diminuição na quantidade de glomérulos e aumento no tamanho destes, nos grupos diabéticos, quando comparado aos grupos controles (p<0,05). E o exercício mostrou-se eficiente na redução da fibrose glomerular e da fibrose tubular. Os resultados mostram que a aplicação do exercício físico aeróbio moderado, em animais de um modelo experimental diabetes tipo 1 foi capaz de prevenir e/ouo tratar danos renais causados pela doença

Effect of photobiomodulation and exercise on early remodeling of the Achilles tendon in streptozotocin-induced diabetic rats.

The aim of this study was to compare the treatment effects of laser photobiomodulation (LPBM) therapy and aerobic exercise on the biomechanical properties, tissue morphology and the expression of tendon matrix molecules during early remodeling of Achilles tendon (AT) injury in diabetic rats. Animals were randomly assigned to five groups: injured non diabetic (I, n = 15), injured diabetic (ID, n = 15), injured diabetic plus LPBM (IDL, n = 16), injured diabetic plus aerobic exercise (IDE, n = 16) and injured diabetic plus aerobic exercise and LPBM (IDEAL, n = 17). Type 1 diabetes was induced via a single intravenous injection of Streptozotocin at a dose of 40 mg/kg. A partial tenotomy was performed in the right AT. LPBM was performed with an indium-gallium-aluminum-phosphide 660 nm 10 mW laser device (spot size 0.04 cm2, power density 250 mW/cm2, irradiation duration 16 s, energy 0.16 J, energy density 4 J/cm2) on alternate days for a total of 9 sessions over 3 weeks (total energy 1.44 J), using a stationary contact technique to a single point over the dorsal aspect of the AT. Moderate aerobic exercise was performed on a motorized treadmill (velocity 9 m/min for 60 minutes). At 3 weeks post-injury, biomechanical analyzes as well as assessment of fibroblast number and orientation were performed. Collagen 1 (Col1) and 3 (Col3) and matrix metalloproteinases (MMPs) -3 and 13 protein distributions were studied by immunohistochemistry; while Col1 and Col3 and MMP-2 and 9 gene expression were assessed by quantitative RT-PCR (qRT-PCR). IDEAL exhibited significant increases in several biomechanical parameters in comparison to the other groups. Moreover, IDEAL presented stronger Col1 immunoreactivity when compared to ID, and weaker Col3 immunoreactivity than IDE. Both IDL and IDEAL demonstrated weaker expression of MMP-3 in comparison to I, while IDL presented no expression of MMP-13 when compared to ID. ID, IDL and IDE showed an increased number of fibroblasts in comparison to I, while IDEAL decreased the number of these cells in comparison to ID and IDE. IDL and IDEAL groups exhibited decreased angular dispersion among the fibroblasts when compared to I. The gene expression results showed that IDE demonstrated a downregulation in Col1 mRNA expression in comparison to I and ID. IDEAL demonstrated upregulation of Col1 mRNA expression when compared to IDL or IDE alone and increased MMP-2 expression when compared to IDL and IDE. MMP-9 expression was upregulated in IDEAL when compared to I, IDL and IDE. Our results suggest a beneficial interaction of combining both treatment strategies i.e., aerobic exercise and LPBM, on the biomechanical properties, tissue morphology and the expression of matrix molecules in diabetic tendons

Protection against T1DM-Induced Bone Loss by Zinc Supplementation: Biomechanical, Histomorphometric, and Molecular Analyses in STZ-Induced Diabetic Rats.

Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young's modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective effect of zinc under chronic diabetic conditions. Furthermore, these results indicate that zinc supplementation could act as a complementary therapy in chronic T1DM

Relative mRNA expression quantification.

<p><i>RANKL</i> (A), <i>OPG</i> (B), <i>OC</i> (C), <i>COL1A</i> (D), <i>MMP-2</i> (E), and <i>MMP-9</i> (F) mRNA expression in bone tissue of control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS) rats. All data are expressed as fold-change vs. control group values, normalized to <i>GAPDH</i>. Comparisons between groups were analyzed with Kruskal-Wallis ANOVA on Ranks and Dunn’s post-hoc. <i>p</i> < 0.05*^/# vs. control group; <i>p</i> < 0.01*^/## vs. control group.</p

Histological analyses of the right tibias.

<p>Hematoxylin and eosin staining of longitudinal sections of tibias of the control (A), type 1 diabetes mellitus (T1DM) (B), and T1DM plus zinc supplementation (T1DMS) (C) groups. TB, trabecular bone; MS, medullary space; magnification 20X, scale bar: 50 μm.</p

Histomorphometric analyses of structural bone architecture.

<p>Trabecular separation (TbSP, μm) (A), trabecular width (TbWi, μm) (B), and trabecular bone area (BAr, %) (C) of control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS) rats. All data are shown as means ± SEM. Comparisons between groups were analyzed with Kruskal-Wallis ANOVA on Ranks and Dunn’s post-hoc. <i>p</i> < 0.01*^/## vs. control group; <i>p</i> < 0.001*^/### vs. control group; <i>p</i> < 0.05 **^/# vs. T1DM group; <i>p</i> < 0.001**^/### vs. T1DM group.</p

Assessment of collagen deposition by picrosirius red staining.

<p>Tibia staining for collagen content (picrosirius red). Total collagen (A), collagen type I (B), and collagen type III (C) contents of the control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS) groups. All data are shown as means ± SEM. Comparisons between groups were analyzed with Kruskal-Wallis ANOVA on Ranks and Dunn’s post-hoc. <i>p</i> < 0.05 *^/# vs. control group.</p

Tibia biomechanical parameters of control, diabetic, and diabetic plus zinc supplementation groups.

<p>T1DM, type 1 diabetes mellitus; T1DMS, T1DM plus zinc supplementation. All data are shown as means ± SEM. Comparisons between groups were analyzed with Kruskal-Wallis ANOVA on Ranks and Dunn’s post-hoc.</p><p>*^/#<i>p</i> < 0.05 vs. control group;</p><p>*^/##<i>p</i> < 0.01 vs. control group.</p><p>Tibia biomechanical parameters of control, diabetic, and diabetic plus zinc supplementation groups.</p

Biochemical analyses and body weight of control, diabetic, and diabetic plus zinc supplementation groups.

<p>T1DM, type 1 diabetes mellitus; T1DMS, T1DM plus zinc supplementation; ALP, alkaline phosphatase. All data are shown as means ± SEM. Comparisons between groups were analyzed with Kruskal-Wallis ANOVA on Ranks and Dunn’s post-hoc.</p><p>*^/#<i>p</i> < 0.05 vs. control group;</p><p>*^/##<i>p</i> < 0.01 vs. control group;</p><p>*^/###<i>p</i> < 0.001 vs. control group;</p><p>**^/##<i>p</i> < 0.01 vs. T1DM group.</p><p>Biochemical analyses and body weight of control, diabetic, and diabetic plus zinc supplementation groups.</p