Analysis of high-intensity interval training on bone mineral density in an experimental model of type 2 diabetes

Purpose: To analyze the effect of high-intensity interval training (HIIT) on bone mineral density (BMD) in a model of type 2 diabetes mellitus. Methods: Thirty-two male, adult, 12-week-old rats (Rattus norvegicus), of the Wistar lineage, were used. The animals induced to the experimental model received a high fat diet for 10 days and, after that period, intraperitoneal injection of streptozotocin (40 mg·kg­1), dissolved in 20 mmol·L­1 sodium citrate solution (pH = 4.5). The experimental group of diabetes was formed by the animals that, 48 h after the injection of streptozotocin, had fasting blood glucose > 250 mg·dL­1). The animals were randomly divided into four groups with eight animals each: HIIT experimental diabetes; HIIT control; sedentary experimental diabetes and sedentary control. The animals in the HIIT group performed an aerobic exercise protocol on a treadmill inclined at an angle of 15° to the horizontal, with interspersed intensity. Five weekly sessions, lasting 49 min each, were held for 6 weeks. The analysis of cortical bone density (CBD) and BMD were performed by X-ray images using the In-Vivo Xtreme II/Bruker system. Results: For CBD and BMD, when comparing diabetes and control groups, a significant difference was seen between groups in relation to HIIT (p = 0.007). Animals submitted and not submitted to HIIT in the same group showed a significant difference between groups in relation to diabetes (p < 0.001). Conclusions: The HIIT experimental diabetes group had increased CBD and BMD in comparison with the sedentary experimental diabetes group.

Combination of cafeteria diet with intraperitoneally streptozotocin in rats. A type-2 diabetes model

ABSTRACT Purpose To develop a model of induction of type-2 diabetes (DM2) by combining low doses of streptozotocin (STZ) and a cafeteria diet. Methods Forty male Wistar rats (200 g) were allocated into four groups: control (non-diabetic, n = 10); STZ 30 mg/kg (diabetic, n = 10); STZ 35 mg/kg (diabetic,n = 10); and STZ 40 mg/kg (diabetic, n = 10). DM2 was induced with a single intraperitoneal injection of STZ after four weeks of cafeteria diet in the three diabetic groups. All animals were evaluated as for anthropometric, and biochemical analyses, as well as liver, kidney and pancreas histological analyses. Results Lower weight gain, higher water intake, higher Lee index, hyperglycemia and modified total protein, urea, alpha-amylase, as well as insulin resistance, hepatic steatosis, pancreas, and kidney injury were observed in animals treated with 35 and 40 mg/kg of STZ. Conclusions The results show that the experimental model using cafeteria diet associated with 35 mg/kg of STZ is a low-cost model and efficient in order to develop DM2, confirmed by the presence of polydipsia, hyperglycemia, altered biochemical tests, insulin resistance and damages to the liver, pancreas and kidney, which is similar to the disease found in humans.

Fenugreek seed extract alleviates hippocampal dendritic atrophy in streptozotocin induced diabetic rats / El extracto de semillas fenugreek alivia la atrofía dendrítica del hipocampo en ratas diabéticas inducidas por estreptozotocina

SUMMARY: Herbal extracts used for treatment of diabetes has focused mostly on the hypoglycaemic and anti-oxidant property.There are no studies which focused on its effect on dendritic architecture of pyramidal neurons of hippocampus caused by diabetes. This study was taken up to explore the effect of administration of Trigonella foenum-graecum (fenugreek) seed extract on diabetes induced dendritic atrophy in hippocampus. Experimental diabetes was induced in rats by administering single dose of Streptozotocin (60 mg/kg)intraperitoneally.Treatment groups of rats were orally administeredfenugreek seed extract of 1 g/kg body weight for 6 weeks. Followingly they were sacrificed and the brains were removed, processed for the Golgi-Cox stain method.The number of dendritic branching points and intersections were counted in successive radial segments of 20 µm up to a radial distance of 100 micron from soma and analysed by the Sholl's method. The rats with diabetes showed a significant decrease in the dendritic length and branching points in most of the apical and basal dendrites of CA1 and CA3 pyramidal neurons.Treatment with fenugreek seed extract were able to significantly alleviate the dendritic atrophy in most of the segments except in the apical branching points of the CA1 neuron. The present study demonstrates that fenugreek seed extract having a proven hypoglycaemic and anti-diabetic property also possess protection to the hippocampal pyramidal neurons form diabetes associated neuronal atrophy.

RESUMEN: Los extractos de hierbas para el tratamiento de la diabetes se han basado principalmente en las propiedades hipoglucémicas y antioxidantes. En la literatura no hay estudios basados en su efecto sobre la arquitectura dendrítica de las neuronas piramidales del hipocampo, causadas por la diabetes. El objetivo de este estudio fue investigar el efecto de la administración de extracto de semilla de Trigonella foenum graecum (fenogreco) sobre la atrofia dendrítica inducida por la diabetes en el hipocampo. Se indujo diabetes experimental en ratas mediante la administración de una dosis única de estreptozotocina (60 mg / kg) por vía intraperitoneal. Se administró a grupos de ratas extracto de semilla de fenogreco a razón de 1 g / kg de peso corporal durante 6 semanas. Las ratas fueron sacrificadas posteriormente y se procesaron los cerebros mediante método de tinción de Golgi-Cox. El número de puntos de ramificación dendrítica e intersecciones se contaron en segmentos radiales sucesivos de 20 µm hasta una distancia radial de 100 micras del soma y se analizaron mediante el método de Sholl. Las ratas con diabetes mostraron una disminución significativa en la longitud dendrítica y los puntos de ramificación en la mayoría de las dendritas apicales y basales de las neuronas piramidales CA1 y CA3. El tratamiento con extracto de semilla de fenogreco alivió significativamente la atrofia dendrítica en la mayoría de los casos, excepto en los puntos de ramificación apical de la neurona CA1. El estudio demuestra que el extracto de semilla de fenogreco además de tener propiedades hipoglucémicas y antidiabéticas, también protege las neuronas piramidales del hipocampo contra la atrofia neuronal asociada a la diabetes.

Preventive role of gum Arabic administration on STZ induced diabetic kidney disease in rats; renal antioxidant and histopathological evidence / Función preventiva de la administración de goma arábiga en la enfermedad renal diabética inducida por STZ en ratas; antioxidante renal y evidencia histopatológica

This study was set to investigate the effect of gum Arabic (G.A.) on diabetic kidney disease. We divided sixty male Sprague rats randomly into six groups. Normal control, normal rats treated with G.A., untreated diabetic rats, diabetic rats treated with insulin, diabetic rats treated with G.A., and diabetic rats treated with both insulin and G.A. Diabetes was induced by a single intraperitoneal injection of STZ. Forty eight hr post injections. Insulin was injected subcutaneously (1.6/IU/100g/day). We provided G.A. in drinking water (10 %w/ v).). At the end of the twelve weeks, blood was drawn for measurement of blood glucose, glycosylated hemoglobin (HbA1C), serum lipids, serum creatinine, and blood urea. Renal tissue oxidative stress (O.S.) was assessed by measuring the activities of superoxide dismutase (SOD) and catalase (CAT), and the concentrations of reduced glutathione (GSH) and malondialdehyde (MDA). For histological assessments, sections from segments of kidneys were processed and stained with hematoxylin and eosin (H&E) for assessment under the light microscope. STZinduced diabetes caused an elevation of blood glucose, HbA1c, urea and creatinine, triglycerides LDL and cholesterol, MDA with reduction of HDL, GSH level, and CAT and SOD activities. Histologically, kidneys from diabetic rats showed marked glomerular and tubular changes. Administration of G.A. alone to diabetic rats had a significant hypoglycemic, hypolipidemic, and antioxidant effect, although the levels achieved remained significantly abnormal compared with the untreated group with no effect on urea and creatinine levels. Co-administration of G.A. with insulin reversed the impact of D.M. on all parameters evaluated including the histological changes and led to normal urea and creatinine levels. We concluded that G.A., in combination with insulin, improves chemically-induced diabetes and its renal complications, possibly by modulation of oxidative stress.

En este estudio se evaluó el efecto de la goma arábiga (GA) en la enfermedad renal diabética. Dividimos sesenta ratas macho Sprague Dawley al azar en seis grupos. Control normal, ratas normales tratadas con GA, ratas diabéticas no tratadas, ratas diabéticas tratadas con insulina, ratas diabéticas tratadas con GA y ratas diabéticas tratadas con insulina y GA. La diabetes fue inducida por una sola inyección intraperitoneal de STZ. Cuarenta y ocho horas después se inyectó insulina por vía subcutánea (1,6 / UI / 100 g / día). A los animales se les dió GA en agua potable (10 % p / v)). Al final de las doce semanas, se extrajo sangre para medir la glucosa, la hemoglobina glicosilada (HbA1C), los lípidos en suero, la creatinina en suero y la urea en sangre. El estrés oxidativo del tejido renal (SO) se evaluó midiendo las actividades de la enzima superóxido dismutasa (SOD) y la catalasa (CAT), y las concentraciones de glutatión reducido (GSH) y malondialdehído (MDA). Para las evaluaciones histológicas, se procesaron secciones de segmentos de riñones y se tiñeron con hematoxilina y eosina (H & E) para análisis bajo microscopio óptico. La diabetes inducida por STZ causó una elevación de la glucosa en sangre, HbA1c, urea y creatinina, triglicéridos LDL y colesterol, MDA con reducción de las actividades de HDL, GSH y CAT y SOD. Histológicamente, los riñones de ratas diabéticas mostraron marcados cambios glomerulares y tubulares. La administración de GA solo en las ratas diabéticas tuvo un efecto hipoglucémico, hipolipidémico y antioxidante significativo, aunque los niveles alcanzados permanecieron significativamente anormales en comparación con el grupo no tratado, sin ningún efecto sobre los niveles de urea y creatinina. La dministración conjunta de GA con insulina revirtió el impacto de DM en todos los parámetros evaluados, incluidos los cambios histológicos y condujeron a niveles normales de urea y creatinina. Concluimos que GA en combinación con insulina, mejora la diabetes inducida químicamente y sus complicaciones renales, posiblemente mediante la modulación del estrés oxidativo.

Actividad de las enzimas pancreáticas exocrinas en ratas hembras diabéticas / Activity of exocrine pancreatic enzymes in diabetic female rats

The study designed to evaluated the activity of pancreatic exocrine enzymes in diabetic male rats induced by alloxan. The hyperglycaemia was induced in forty-five rats after fasting of the animals for 24 hours by single intraperitoneal (i.p) injection of Alloxan100mg/kg B.W., three days after injection fasting blood glucose was measured when the concentration higher than 150mg/dL, were considered as hyperglycemic/ diabetes. A total of sixty adult male rats (45 diabetes and 15 non- diabetes) divided in to two groups as follows. The first group serves as control groups (15 animals) will be single i.p injection with distilled water. the second group diabetic groups (45 animals from first experiment) were subdivided into three subgroups as following (15 for each). Group (G1), Group (G2) and Group (G3) serves as 20, 40- and 60-days diabetic animals respectively. The blood samples collection were take through cardiac puncture technique from each rat for each period days for measurement the following parameters: (Serum glucose, total protein, insulin, cholesterol, albumin, triglyceride, LDL-C, HDL-C and VLDL-C) concentration, the rats pancreatic tissue were be taken for measured tissue pancreatic lipase, amylase, and trypsin concentration. The results demonstrate a significant increase in serum glucose concentration and a decrease in serum insulin and total protein in the diabetic group as compared with the control rats' group in all experimental days. The results showed a significant rise in serum total cholesterol concentration within the diabetic group when compared with the control group at day 20 and 60. Meanwhile, a significant increase in serum triglyceride and LDL concentration and a significant decrease in serum HDL concentration within the diabetic group when compared with the control rats group at day 20, 40 and 60. But the serum VLDL concentration depicted a significant increase in the group of diabetic when compared with the control rats group at day 40 and 60. The value of pancreatic tissue protease activity clarified there was a significant decrease of protease action in the group of diabetic rats when compared with the control rats group on both day 20 and day 60. And a significant decrease in amylase activity in the diabetic groups when compared with the group of control rats in both day 20, 40 and day 60. While the results of pancreatic tissue lipase show there were non-significant changes within the diabetics group when compared with the control group. In conclusion, the exocrine pancreatic function is very frequently and severely altered in diabetes mellitus male rats and the metabolic disorder effect of diabetes mellitus was manifested by hyperlipidemic and hypoprotenimic .

CX3CR1 contributes to streptozotocin-induced mechanical allodynia in the mouse spinal cord / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Patients with diabetic peripheral neuropathy experience debilitating pain that significantly affects their quality of life (Abbott et al., 2011), by causing sleeping disorders, anxiety, and depression (Dermanovic Dobrota et al., 2014). The primary clinical manifestation of painful diabetic neuropathy (PDN) is mechanical hypersensitivity, also known as mechanical allodynia (MA) (Callaghan et al., 2012). MA's underlying mechanism remains poorly understood, and so far, based on symptomatic treatment, it has no effective therapy (Moore et al., 2014).

Spinal P2X7R contributes to streptozotocin-induced mechanical allodynia in mice / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Painful diabetic neuropathy (PDN) is a diabetes mellitus complication. Unfortunately, the mechanisms underlying PDN are still poorly understood. Adenosine triphosphate (ATP)-gated P2X7 receptor (P2X7R) plays a pivotal role in non-diabetic neuropathic pain, but little is known about its effects on streptozotocin (STZ)-induced peripheral neuropathy. Here, we explored whether spinal cord P2X7R was correlated with the generation of mechanical allodynia (MA) in STZ-induced type 1 diabetic neuropathy in mice. MA was assessed by measuring paw withdrawal thresholds and western blotting. Immunohistochemistry was applied to analyze the protein expression levels and localization of P2X7R. STZ-induced mice expressed increased P2X7R in the dorsal horn of the lumbar spinal cord during MA. Mice injected intrathecally with a selective antagonist of P2X7R and P2X7R knockout (KO) mice both presented attenuated progression of MA. Double-immunofluorescent labeling demonstrated that P2X7R-positive cells were mostly co-expressed with Iba1 (a microglia marker). Our results suggest that P2X7R plays an important role in the development of MA and could be used as a cellular target for treating PDN.

Effects of vitamin C local application on ligature-induced periodontitis in diabetic rats

Abstract Objective: This study evaluated the effects of local vitamin C treatment on tissue advanced glycation end products (AGE), interleukin (IL)-6, 8-hydroxy-2-deoxyguanosine (8-OHdG), and matrix metalloproteinases (MMP)-8 in tissues; serum C-terminal telopeptide fragments (CTX); and alveolar bone loss (ABL) in rats. Methodology: 35 male Sprague Dawley rats were divided equally into five groups: 1) control (C), 2) experimental periodontitis (P), 3) experimental diabetes (D), 4) experimental diabetes and experimental periodontitis (D + P), and 5) experimental diabetes-experimental periodontitis-locally applied vitamin C (D + P + LvitC). Diabetes was induced in rats with alloxan monohydrate, after which periodontitis was induced by ligature placement in the right mandibular first molar teeth for 11 days. In the treatment group, vitamin C was administered locally three times with two-days interval after ligature removal. The animals were sacrificed, and the samples were analyzed histometrically and immunohistochemically. Results: CTX, 8-OHdG, and AGE values significantly decreased in the treatment group compared to the D + P group. IL-6 and MMP-8 values decreased in the treatment group compared to the D + P group, but this is not significant. ABL was significantly reduced by the local delivery of vitamin C. Conclusion: This study reveals that vitamin C treatment may be beneficial to reduce serum CTX and gingival MMP-8 levels, oxidative stress, inflammation, and AGE accumulation in periodontal tissue. Vitamin C may be an immunomodulator and antioxidant locally applied in the treatment of periodontitis to reduce the adverse effects of diabetes in periodontal tissues.

The Effects of Trimetazidine on QT-interval Prolongation and Cardiac Hypertrophy in Diabetic Rats / Os Efeitos da Trimetazidina no Prolongamento do Intervalo QT e na Hipertrofia Cardíaca em Ratos Diabéticos

Abstract Background: Trimetazidine (TMZ) is an anti-ischemic drug. In spite of its protective effects on cardiovascular system, there is no scientific study on the usefulness of TMZ treatment for prolonged QT interval and cardiac hypertrophy induced by diabetes. Objectives: To evaluate the effects of TMZ on QT interval prolongation and cardiac hypertrophy in the diabetic rats. Methods: Twenty-four male Sprague-Dawley rats (200-250 g) were randomly assigned into three groups (n = 8) by simple random sampling method. Control (C), diabetic (D), and diabetic administrated with TMZ at 10 mg/kg (T10). TMZ was administrated for 8 weeks. The echocardiogram was recorded before isolating the hearts and transfer to a Langendorff apparatus. Hemodynamic parameters, QT and corrected QT interval (QTc) intervals, heart rate and antioxidant enzymes were measured. The hypertrophy index was calculated. The results were evaluated by one-way ANOVA and paired t-test using SPSS (version 16) and p < 0.05 was regarded as significant. Results: The diabetic rats significantly indicated increased hypertrophy, QT and QTc intervals and decreased Left ventricular systolic pressure (LVSP), Left ventricular developed pressure (LVDP), rate pressure product (RPP), Max dp/dt, and min dp/dt (±dp/dt max), heart rate, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase in the heart. Treatment with TMZ in the diabetic animals was significantly improved these parameters in comparison to the untreated diabetic group. Conclusions: TMZ improves QTc interval prolongation and cardiac hypertrophy in diabetes.

Resumo Fundamento: A trimetazidina (TMZ) é uma droga anti-isquêmica. Apesar de seus efeitos protetores sobre o sistema cardiovascular, não há estudos científicos sobre a utilidade do tratamento com TMZ para o intervalo QT prolongado e a hipertrofia cardíaca induzida pelo diabetes. Objetivo: Avaliar os efeitos da TMZ no prolongamento do intervalo QT e na hipertrofia cardíaca em ratos diabéticos. Métodos: Vinte e quatro ratos machos Sprague-Dawley (200-250 g) foram distribuídos aleatoriamente em três grupos (n = 8) pelo método de amostragem aleatória simples. Controle (C), diabético (D) e diabético administrado com TMZ a 10 mg/kg (T10). A TMZ foi administrada por 8 semanas. O ecocardiograma foi registrado antes de isolar os corações e transferir para um aparelho de Langendorff. Foram medidos os parâmetros hemodinâmicos, intervalo QT e intervalo QT corrigido (QTc), frequência cardíaca e enzimas antioxidantes. O índice de hipertrofia foi calculado. Os resultados foram avaliados pelo one-way ANOVA e pelo teste t pareado pelo SPSS (versão 16) e p < 0,05 foi considerado significativo. Resultados: Os ratos diabéticos indicaram hipertrofia aumentada, intervalos QT e QTc e diminuição da pressão sistólica no ventrículo esquerdo (PSVE), pressão desenvolvida no ventrículo esquerdo (PDVE), duplo produto (DP), Max dp/dt e min dp/dt (± dp/dt max), frequência cardíaca, superóxido dismutase (SOD), glutationa peroxidase (GPx) e catalase no coração. O tratamento com TMZ nos animais diabéticos melhorou significativamente esses parâmetros em comparação com o grupo diabético não tratado. Conclusões: A TMZ melhora o prolongamento do intervalo QTc e a hipertrofia cardíaca no diabetes.

Experimental study on effect and mechanism of Danzhi Jiangtang Capsules on diabetic myocardial injury / 中国中药杂志

Diabetic cardiomyopathy( DCM) is one of the major cardiovascular complications of diabetes mellitus. Based on the clinical efficacy of Danzhi Jiangtang Capsules( DJC) in the prevention and treatment of diabetes and its cardiovascular complications,both in vivo and in vitro methods were adopted to investigate its effect and underlying mechanism of protecting myocardial injury induced by diabetes. The type 2 diabetic rats were prepared by feeding high-energy food combined with streptozotin( STZ) injection,and the effects of DJC were observed by blood sugar,blood lipid,hemodynamic index,cardiac weight index and the change of cardiac pathological morphology. The protein expressions of TLR4,MyD88 and NF-κB p65 in myocardial tissue were detected and the possible mechanism was preliminarily analyzed. Besides this,DJC containing serum was prepared,H9 c2 cardiomyocyte induced by high sugar were studied to investigate the mechanism of TLR4/MyD88/NF-κB signaling pathway regulating cardiomyocyte injury and the therapeutic effect of DJC. The results demonstrated that fasting blood sugar,glycosylated hemoglobin,total cholesterol and glycerol triglyceride were significantly reduced( P<0. 01,P<0. 05). Cardiac weight index,left ventricle weight index,LVEDP and the protein expressions of TLR4,MyD88 and NF-κB p65 were significantly reduced( P<0. 01,P<0. 05). LVSP,+dp/dtmaxand-dp/dtmaxincreased significantly( P<0. 01,P< 0. 05). Moreover,the pathological damage of myocardial tissue in rats improved significantly. Meanwhile,the protein expressions of TLR4,MyD88 and NF-κB p65 in cardiomyocytes induced by high sugar were significantly inhibited( P<0. 01).It showed that DJC were effective in preventing and treating myocardial injury induced by diabetes and its mechanism may be related to the over-expression of TLR4/MyD88/NF-κB signaling pathway induced by high sugar.

IGF-1R/β-catenin signaling axis is involved in type 2 diabetic osteoporosis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Insulin-like growth factor-1 receptor (IGF-1R) is involved in both glucose and bone metabolism. IGF-1R signaling regulates the canonical Wnt/β-catenin signaling pathway. In this study, we investigated whether the IGF-1R/ β-catenin signaling axis plays a role in the pathogenesis of diabetic osteoporosis (DOP). Serum from patients with or without DOP was collected to measure the IGF-1R level using enzyme-linked immunosorbent assay (ELISA). Rats were given streptozotocin following a four-week high-fat diet induction (DOP group), or received vehicle after the same period of a normal diet (control group). Dual energy X-ray absorption, a biomechanics test, and hematoxylin-eosin (HE) staining were performed to evaluate bone mass, bone strength, and histomorphology, respectively, in vertebrae. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were performed to measure the total and phosphorylation levels of IGF-1R, glycogen synthase kinase-3β (GSK-3β), and β-catenin. The serum IGF-1R level was much higher in patients with DOP than in controls. DOP rats exhibited strikingly reduced bone mass and attenuated compression strength of the vertebrae compared with the control group. HE staining showed that the histomorphology of DOP vertebrae was seriously impaired, which manifested as decreased and thinned trabeculae and increased lipid droplets within trabeculae. PCR analysis demonstrated that IGF-1R mRNA expression was significantly up-regulated, and western blotting detection showed that phosphorylation levels of IGF-1R, GSK-3β, and β-catenin were enhanced in DOP rat vertebrae. Our results suggest that the IGF-1R/β-catenin signaling axis plays a role in the pathogenesis of DOP. This may contribute to development of the underlying therapeutic target for DOP.

Metformin pretreatment ameliorates diabetic nephropathy induced by a combination of high fat diet and streptozotocin in rats / El pretratamiento con metformina mejora la nefropatía diabética inducida por una combinación de dieta alta en grasas y estreptozotocina en ratas

Kidney injury secondary to diabetes is the most common cause of kidney failure. We sought to determine whether pretreatment with the insulin-sensitizing drug metformin prior to the induction of diabetes can protect the kidney against the development of diabetic nephropathy (DN) induced by a combination of a high-fat diet and streptozotocin. Rats were either injected with vehicle (control group) or with a single injection of streptozotocin (STZ) (50 mg/kg) two weeks after being fed on a high-fat diet (HFD) (model group) and continued on HFD until being sacrificed 10 weeks post diabetic induction. The protective group that also fed on a HFD for 12 weeks was put on metformin (200 mg/kg/day) two weeks before STZ injection and continued on metformin until the sacrifice day. Harvested kidney tissues were examined by light microscopy after staining with hematoxylin and eosin (H&E) and periodic acid Schiff (PAS). Blood samples were assayed for sugar, urea, creatinine, and biomarkers of inflammation. Compared to a normal tissue histology in the control group, there was a profound damage to the kidney in the model group as demonstrated by markedly dilated capsular space, increased mesangial matrix expansion, congested blood vessels, and many tubular epithelial cells showing small pyknotic nuclei and vacuolated cytoplasm, which were significantly but not completely protected by metformin. Our findings also show that metformin significantly inhibited the inflammatory biomarkers, tumor necrosis factor-alpha (TNF-α) and C-reactive protein (CRP) induced by diabetes and HFD as well as significantly inhibiting blood sugar, urea, and creatinine. However, the levels of TNF-α, CRP, glucose, and creatinine in the metformin-treated group was still significant to the control group. Thus, we demonstrated an efficient but not complete protection by metformin pretreatment against DN induced by a combination of HFD and streptozotocin in rats.

La lesión renal secundaria a la diabetes es la causa más común de insuficiencia renal. Intentamos determinar si el pre tratamiento con metformina, un fármaco sensibilizante a la insulina antes de la inducción de diabetes, puede proteger al riñón del desarrollo de la nefropatía diabética (DN) inducida por una combinación de una dieta alta en grasas y estreptozotocina. Las ratas fueron inyectadas con el medio (grupo de control) o con una inyección única de estreptozotocina (STZ) (50 mg / kg) dos semanas después de ser alimentadas con una dieta alta en grasas (HFD) (grupo modelo) y continuaron en HFD hasta ser sacrificadas 10 semanas después de la inducción diabética. El grupo protector que también se alimentó con un HFD durante 12 semanas recibió metformina (200 mg / kg / día) dos semanas antes de la inyección de STZ y continuó con metformina hasta el día en que fueron sacrificadas. Las muestras de riñón se examinaron mediante microscopía óptica después de la tinción con Hematoxilina y Eosina y ácido peryódico de Schiff (PAS). Las muestras de sangre se analizaron para determinar niveles de azúcar, urea, creatinina y biomarcadores de inflamación. Comparado con una histología tisular normal en el grupo control, hubo un daño profundo al riñón en el grupo modelo como lo demuestra el espacio capsular marcadamente dilatado, el aumento de la expansión de la matriz mesangial, los vasos sanguíneos congestionados y muchas células epiteliales tubulares que muestran pequeños núcleos picnóticos y citoplasma vacuolado, que fueron significativamente pero no completamente protegidos por la metformina. Nuestros hallazgos también muestran que la metformina inhibe significativamente los biomarcadores inflamatorios, el factor de necrosis tumoral alfa (TNF-a) y la proteína C reactiva (PCR) inducida por diabetes y DFH, e inhibe significativamente el azúcar en sangre, la urea y la creatinina. Sin embargo, los niveles de TNF-a, CRP, glucosa y creatinina en el grupo tratado con metformina todavía eran significativos para el grupo de control. Por lo tanto, demostramos una protección eficiente pero no completa mediante pretratamiento con metformina contra DN inducida por una combinación de HFD y estreptozotocina en ratas.

A curcumin derivative J147 ameliorates diabetic peripheral neuropathy in streptozotocin (STZ)-induced DPN rat models through negative regulation AMPK on TRPA1

Abstract Purpose: To investigate the specific molecular mechanisms and effects of curcumin derivative J147 on diabetic peripheral neuropathy (DPN). Methods: We constructed streptozotocin (STZ)-induced DPN rat models to detected mechanical withdrawal threshold (MWT) in vivo using Von Frey filaments. In vitro, we measured cell viability and apoptosis, adenosine 5'-monophosphate-activated protein kinase (AMPK) and transient receptor potential A1 (TRPA1) expression using MTT, flow cytometry, qRT-PCR and western blot. Then, TRPA1 expression level and calcium reaction level were assessed in agonist AICAR treated RSC96cells. Results: The results showed that J147reduced MWT in vivo, increased the mRNA and protein level of AMPK, reduced TRPA1 expression and calcium reaction level in AITCR treated RSC96 cells, and had no obvious effect on cell viability and apoptosis. Besides, AMPK negative regulated TRPA1 expression in RSC96 cells. Conclusions: J147 could ameliorate DPN via negative regulation AMPK on TRPA1 in vivo and in vitro. A curcumin derivative J147might be a new therapeutic potential for the treatment of DPN.

Effect of melatonin on antioxidant capacity, inflammation and apoptotic cell death in lung tissue of diabetic rats

Abstract Purpose: To investigate the effects of melatonin on antioxidant capacity, inflammation and apoptotic cell death (through expression of cleaved-caspase 3) in lung tissue samples of diabetic rats. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control group) was made up of healthy rats. Group 2 (diabetes group) received streptozotocin at a dose of 50 mg/kg/day for 5 days.Group 3 (diabetes plus melatonin group) received streptozotocin at a dose of 50 mg/kg/day for 5 days and then they received melatonin at a dose of 20 mg/kg/day between 28thand 35thdays of the study. Results: Tissue MDA and MPO levels were found to be significantly higher in diabetes group compared to control group (p<0.05) whilst administration of melatonin was found to significantly lower this increase down to normal levels (p<0.05). Bronchus associated lymphoid tissue (BALT) was more severe in diabetics whereas administration of melatonin alleviated this hyperplasia. Cleaved caspase 3 activity was severe in hyperplastic BALT in diabetic rats however in lowered down to moderate level when melatonin was administered. Conclusion: The melatonin caused an increase in antioxidant capacity and decreased the expression of cleaved-caspase 3.

Investigation of the effect of gestational diabetes on fetal cardiac tissue in streptozotocin induced in rats

Abstract Purpose: To investigate the cause of congenital anomalies resulted from gestational diabetes on fetal cardiac tissue in experimental animal study model. Methods: Totally 12 female Wistar albino rats were divided into two groups, each consisting of 6 rats. Streptozotocin (60 mg/kg) was administered intraperitoneally to the study group by dissolving in citrate solution. The rats with a blood glucose level of 200 mg/dL and above were considered to be diabetic rats. Total antioxidant status (TAS), total oxidative stress (TOS) and oxidative stress index (OSI) values were calculated in the cardiac tissues and maternal serum samples of the fetuses delivered by cesarean section after the mating process. The cardiac tissues were also subjected to histopathological examination. Results: TOS and OSI values in fetal cardiac tissues of the diabetic rats were found to be significantly higher than that of the control group (p=0.026 and p=0.005). Histopathological examination revealed that the mitotic index was lower and the cell organization was found to be damaged in the fetuses of the study group rats. Conclusion: Increased levels of free oxygen radicals considered to be due to hyperglycemia may cause congenital anomalies, especially during organogenesis period, by disrupting cell homeostasis and adversely affecting mitosis.

Expression profile of endothelin receptors (ETA and ETB) and microRNAs-155 and -199 in the corpus cavernosum of rats submitted to chronic alcoholism and diabetes mellitus

Recent evidence shows that chronic ethanol consumption increases endothelin (ET)-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D), and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.

Calpain inhibition improves erectile function in diabetic mice via upregulating endothelial nitric oxide synthase expression and reducing apoptosis / 亚洲男科学杂志(英文版)

Calpain activation contributes to hyperglycemia-induced endothelial dysfunction and apoptosis. This study was designed to investigate the role of calpain inhibition in improving diabetic erectile dysfunction (ED) in mice. Thirty-eight-week-old male C57BL/6J mice were divided into three groups: (1) nondiabetic control group, (2) diabetic mice + vehicle group, and (3) diabetic mice + MDL28170 (an inhibitor of calpain) group. Type 1 diabetes was induced by intraperitoneal injection of streptozotocin at 60 mg kg-1 body weight for 5 consecutive days. Thirteen weeks later, diabetic mice were treated with MDL28170 or vehicle for 4 weeks. The erectile function was assessed by electrical stimulation of the cavernous nerve. Penile tissues were collected for measurement of calpain activity and the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway. Terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining was used to evaluate apoptosis. Caspase-3 expression and activity were also measured to determine apoptosis. Our results showed that erectile function was enhanced by MDL28170 treatment in diabetic mice compared with the vehicle diabetic group. No differences in calpain-1 and calpain-2 expressions were observed among the three groups. However, calpain activity was increased in the diabetic group and reduced by MDL28170. The eNOS-NO-cGMP pathway was upregulated by MDL28170 treatment in diabetic mice. Additionally, MDL28170 could attenuate apoptosis and increase the endothelium and smooth muscle levels in corpus cavernosum. Inhibition of calpain could improve erectile function, probably by upregulating the eNOS-NO-cGMP pathway and reducing apoptosis.

Protective Effect of Ischemic Preconditioning on Myocardium Against Remote Tissue Injury Following Transient Focal Cerebral Ischemia in Diabetic Rats / Efeito Protetor do Pré-Condicionamento Isquêmico no Miocárdio Contra Lesão Remota de Tecidos após Isquemia Cerebral Focal Transitória em Ratos Diabéticos

Abstract Background: Remote ischemic preconditioning (IPreC) could provide tissue-protective effect at a remote site by anti-inflammatory, neuronal, and humoral signaling pathways. Objectives: The aim of the study was to investigate the possible protective effects of remote IPreC on myocardium after transient middle cerebral artery occlusion (MCAo) in streptozotocin- induced diabetic (STZ) and non-diabetic rats. Methods: 48 male Spraque Dawley rats were divided into eight groups: Sham, STZ, IPreC, MCAo, IPreC+MCAo, STZ+IPreC, STZ+MCAo and STZ+IPreC+MCAo groups. We induced transient MCAo seven days after STZ-induced diabetes, and performed IPreC 72 hours before transient MCAo. Remote myocardial injury was investigated histopathologically. Bax, Bcl2 and caspase-3 protein levels were measured by Western blot analysis. Total antioxidant status (TAS), total oxidant status (TOS) of myocardial tissue were measured by colorimetric assay. Oxidative stress index(OSI) was calculated as TOS-to-TAS ratio. For all statistical analysis, p values < 0.05 were considered significant. Results: We observed serious damage including necrosis, congestion and mononuclear cell infiltration in myocardial tissue of the diabetic and ischemic groups. In these groups TOS and OSI levels were significantly higher; TAS levels were lower than those of IPreC related groups (p < 0.05). IPreC had markedly improved histopathological alterations and increased TAS levels in IPreC+MCAo and STZ+IPreC+MCAo compared to MCAo and STZ+MCAo groups (p < 0.05). In non-diabetic rats, MCAo activated apoptotic cell death via increasing Bax/Bcl2 ratio and caspase-3 levels. IPreC reduced apoptotic cell death by suppressing pro-apoptotic proteins. Diabetes markedly increased apoptotic protein levels and the effect did not reversed by IPreC. Conclusions: We could suggest that IPreC attenuates myocardial injury via ameliorating histological findings, activating antioxidant mechanisms, and inducing antiapoptotic activity in diabetic rats.

Resumo Fundamentos: O pré-condicionamento isquêmico remoto (IPreC) poderia fornecer efeito protetor de tecido em um local remoto por vias de sinalização anti-inflamatórias, neuronais e humorais. Objetivos: O objetivo do estudo foi investigar os possíveis efeitos protetores do IPreC remoto no miocárdio após a oclusão transitória da artéria cerebral média (MCAo) em ratos com diabetes induzida por estreptozotocina (STZ) e ratos não diabéticos. Métodos: 48 ratos Spraque Dawley machos foram divididos em oito grupos: grupos Sham, STZ, IPreC, MCAo, IPreC + MCAo, STZ + IPreC, STZ + MCAo e STZ + IPreC + MCAo. Induzimos MCAo sete dias após a diabetes induzida por STZ e realizamos IPreC 72 horas antes do MCAo. A lesão miocárdica remota foi investigada histopatologicamente. Os níveis de proteína Bax, Bcl2 e caspase-3 foram medidos pela análise Western Blot. O estado de antioxidante total (TAS), e o estado de oxidação total (TOS) do tecido miocárdico foram medidos por meio de um estudo colorimétrico. O índice de estresse oxidativo (OSI) foi calculado como a relação TOS-TAS. Para todas as análises estatísticas, os valores de p < 0,05 foram considerados significativos. Resultados: Observamos danos graves, incluindo necrose, congestão e infiltração de células mononucleares no tecido miocárdico dos grupos diabético e isquêmico. Nesses grupos os níveis de TOS e OSI foram significativamente maiores; os níveis de TAS foram inferiores aos dos grupos relacionados com IPreC (p < 0,05). O IPreC melhorou marcadamente as alterações histopatológicas e aumentou os níveis de TAS em IPreC + MCAo e STZ + IPreC + MCAo em comparação com os grupos MCAo e STZ + MCAo (p < 0,05). Em ratos não diabéticos, MCAo activou a morte celular apoptótica através do aumento da relação Bax / Bcl2 e dos níveis de caspase-3. IPreC reduziu a morte celular apoptótica pela supressão de proteínas pró-apoptóticas. O diabetes aumentou acentuadamente os níveis de proteína apoptótica e o efeito não foi revertido pelo IPreC. Conclusões: Podemos sugerir que o IPreC atenua a lesão miocárdica através da melhora dos achados histológicos, ativando mecanismos antioxidantes e induzindo atividade antiapoptótica em ratos diabéticos.

Diabetic Rats Present High Mean Platelet Count in the Presence of Oral Infections

Abstract Platelet count is associated with inflammatory diseases like diabetes mellitus (DM), which in turn, is related in a bidirectional manner with apical periodontitis and periodontal disease. The aim of this study was to evaluate the effects of apical periodontitis and/or periodontal disease on mean platelet count in a rat model of diabetes mellitus. Eighty Wistar rats were randomly divided into 8 groups (n=10): control (C), apical periodontitis (AP), periodontal disease (PD), apical periodontitis with periodontal disease (AP-PD), diabetes mellitus (DM), diabetes mellitus with apical periodontitis (DM-AP), diabetes mellitus with periodontal disease (DM-PD) and diabetes mellitus with apical periodontitis and periodontal disease (DM-AP-PD). Rats were anesthetized and DM was induced with a single dose of streptozotocin diluted in citrate buffer solution. After 6 days, the DM was confirmed. The animals were sedated and apical periodontitis was induced by dental exposure and periodontal disease was induced by periodontal ligature. After 30 days, animals were anesthetized and the blood was collected by cardiac puncture. Samples were processed and the mean platelet count was obtained. Data were tabulated and subjected to statistical analysis (p<0.05). Diabetic rats had higher mean glycemic levels compared with nondiabetic rats at 6 and 36 days after DM induction (p<0.05). The DM-PD and DM-PD-AP groups showed increased mean platelet count compared to control and AP groups (p<0.05). The periodontal disease alone or associated with apical periodontitis influence mean platelet count in a rat model of diabetes mellitus.

Resumo A contagem de plaquetas está associada a doenças inflamatórias como a diabetes mellitus (DM), que, por sua vez, está relacionada de forma bidirecional com periodontite apical e com a doença periodontal. O objetivo deste estudo foi avaliar os efeitos da periodontite apical e/ou da doença periodontal na contagem de plaquetas utilizando o modelo de rato para DM. Oitenta ratos Wistar foram divididos aleatoriamente em 8 grupos (n=10): controle (C), periodontite apical (AP), doença periodontal (PD), periodontite apical com doença periodontal (AP-PD), diabetes mellitus (DM), diabetes mellitus com periodontite apical (DM-AP), diabetes mellitus com doença periodontal (DM-PD) e diabetes mellitus com periodontite apical e doença periodontal (DM-AP-PD). Os ratos foram anestesiados e a DM foi induzida com uma dose única de estreptozotocina diluída na solução tampão citrato. Após 6 dias, o DM foi confirmada. Os animais foram sedados e a periodontite apical foi induzida pela exposição dentária e a doença periodontal foi induzida por ligadura periodontal. Após 30 dias, os animais foram anestesiados e o sangue foi coletado por punção cardíaca. As amostras foram processadas e a contagem média de plaquetas foi obtida. Os dados foram tabulados e submetidos a análise estatística (p <0,05). Os ratos diabéticos apresentaram níveis glicêmicos médios mais elevados em comparação com ratos não diabéticos aos 6 e 36 dias após a indução da DM (p <0,05). Os grupos DM-PD e DM-PD-AP mostraram aumento da contagem média de plaquetas em comparação com os grupos controle e AP (p <0,05). A doença periodontal isolada ou associada à periodontite apical influencia na contagem de plaquetas em modelo de rato para diabetes mellitus.

Penile alterations at early stage of type 1 diabetes in rats

ABSTRACT Objective Diabetes affects the erectile function significantly. However, the penile alterations in the early stage of diabetes in experimental animal models have not been well studied. We examined the changes of the penis and its main erectile components in diabetic rats. Materials and methods Male Sprague-Dawley rats were divided into 2 groups: streptozotocin (STZ)-induced diabetics and age-matched controls. Three or nine weeks after diabetes induction, the penis was removed for immunohistochemical staining of smooth muscle and neuronal nitric oxide synthase (nNOS) in midshaft penile tissues. The cross-sectional areas of the whole midshaft penis and the corpora cavernosa were quantified. The smooth muscle in the corpora cavernosa and nNOS in the dorsal nerves were quantified. Results The weight, but not the length, of the penis was lower in diabetics. The cross-sectional areas of the total midshaft penis and the corpora cavernosa were lower in diabetic rats compared with controls 9 weeks, but not 3 weeks after diabetes induction. The cross-sectional area of smooth muscle in the corpora cavernosa as percentage of the overall area of the corpora cavernosa was lower in diabetic rats than in controls 9 weeks, but not 3 weeks after diabetes induction. Percentage change of nNOS in dorsal nerves was similar at 3 weeks, and has a decreased trend at 9 weeks in diabetic rats compared with controls. Conclusions Diabetes causes temporal alterations in the penis, and the significant changes in STZ rat model begin 3-9 weeks after induction. Further studies on the reversibility of the observed changes are warranted.