Swim exercise augments the protection of the knee joint against osteoarthritis development in diabetic rats treated with insulin / El ejercicio de natación aumenta la protección de la articulación de la rodilla contra el desarrollo de osteoartritis en ratas diabéticas tratadas con insulina

We recently reported that insulin can partially protect the knee joint against osteoarthritis (OA) development in a rat model of type 1 diabetes mellitus (T1DM). However, the combined protective effect of insulin and swim exercise against OA development secondary to diabetes has not been investigated before. Therefore, we hypothesized that swim exercise can augment the protection of the knee joint in diabetic rats treated with insulin. T1DM was induced in Sprague Dawley rats and treated with insulin and/ or swim exercise. Tissues harvested from the articular cartilage of the knee joint were examined by light microscopy, and blood samples were assayed for biomarkers of oxidative stress and inflammation. Treatment of diabetic rats with insulin and swim exercise substantially protected the articular cartilage and significantly (p<0.0001) inhibited the inflammatory biomarkers, tumor necrosis factor-alpha (TNFα) and interleukin-6 (IL-6), and the oxidative stress biomarker, malondialdehyde (MDA) measured as thiobarbituric acid reactive substances (TBARS) comparable to control. Whereas, a lesser effective protection was observed by insulin or swim exercise alone. Thus, we demonstrate a substantial protection against OA development in rats treated with combined insulin and swim exercise possibly due to a complete inhibition of biomarkers of inflammation and oxidative stress.

Recientemente informamos que la insulina puede proteger parcialmente la articulación de la rodilla contra el desarrollo de osteoartritis (OA) en un modelo de diabetes tipo 1 (DM1) en ratas. Sin embargo, el efecto protector combinado de la insulina y el ejercicio de natación contra el desarrollo de OA secundario a la diabetes no se ha investigado. Por lo tanto, planteamos la hipótesis de que el ejercicio de natación puede aumentar la protección de la articulación de la rodilla en ratas diabéticas tratadas con insulina. La DM1 se indujo en ratas Sprague Dawley y se trataron con insulina y/o ejercicio de natación. Los tejidos recogidos del cartílago articular de la articulación de la rodilla se examinaron mediante microscopía óptica, y las muestras de sangre se analizaron en busca de biomarcadores de estrés oxidativo e inflamación. El tratamiento de ratas diabéticas con insulina y ejercicio de natación protegió sustancialmente el cartílago articular y significativamente (p <0,0001) inhibió los biomarcadores inflamatorios, factor de necrosis tumoral alfa (TNF-α) e interleucina-6 (IL-6) y el biomarcador de estrés oxidativo, el malondialdehído (MDA) fue medido como sustancia reactivas al ácido tiobarbitúrico (TBARS), comparable al control. Se observó una menor protección efectiva mediante la insulina o el ejercicio de natación solo. Por lo tanto, demostramos una protección sustancial contra el desarrollo de OA en ratas tratadas con insulina combinada con el ejercicio de natación, posiblemente debido a una inhibición completa de biomarcadores de inflamación y estrés oxidativo.

Suppression of high fat diet-induced liver cell injury by swim exercise / Supresión de lesión en células de hígado inducida por dieta alta en grasas con ejercicio de natación

SUMMARY: The rapid rise in obesity, particularly among children is a major public health concern that adversely affects vital organs including the liver. We sought to investigate the effect of exercise on the healing of liver cells from damage induced by high fat diet (HFD) in a rat model of hepatic steatosis. Rats were randomly divided into four groups (n=6 in each group); control group fed on a low fat diet (LFD), LFD plus exercise group (LFD+EX), model group fed on HFD, and swim exercise treated group (HFD+EX). Training swim exercise started from the 11th week up until the end of week 15. Liver index and body mass index (BMI) were determined, and harvested liver tissues were examined using basic histological staining and visualised under light microscopy. In addition, collected blood samples were assayed for biomarkers of liver injury. Histological images from the model group showed accumulation of lipid droplets in the hepatocytes (steatosis) and damaged liver cells that were inhibited by swimming exercise. Compared to control groups, HFD caused an increase in BMI and liver weight but not in liver index. In addition, HFD significantly (p<0.05) increased liver injury biomarkers; high-sensitivity C-reactive protein (hsCRP) and alkaline phosphatase (ALP) that were effectively (p<0.05) decreased by swimming exercise. Furthermore, a negative correlation between these biomarkers and the antioxidant and anti-inflammatory protein adiponectin was observed. Thus, HFD-induced hepatic steatosis is treated by swim exercise.

RESUMEN: El aumento de la obesidad, especialmente entre los niños, es un problema importante en la salud pública que afecta negativamente los órganos vitales, incluyendo el hígado. En este estudio se investigó el efecto del ejercicio en la curación de las células del hígado y el daño inducido por la dieta alta en grasas (HFD) en un modelo de rata de esteatosis hepática. Las ratas se dividieron aleatoriamente en cuatro grupos (n = 6 en cada grupo); grupo control, alimentado con una dieta baja en grasas (LFD); grupo de ejercicio LFD más (LFD + EX); grupo modelo alimentado con HFD; y grupo tratado con ejercicio de natación (HFD + EX). El entrenamiento con ejercicio de natación comenzó a partir de la semana 11 hasta el final de la semana 15. Se determinaron el índice hepático y el índice de masa corporal (IMC). Los tejidos hepáticos recolectados se examinaron mediante tinción histológica básica y se visualizaron con microscopía óptica. Además, se analizaron las muestras de sangre recogidas para identificar biomarcadores de lesión hepática. Las imágenes histológicas del grupo modelo mostraron acumulación de gotitas de lípidos en los hepatocitos (esteatosis) y células hepáticas dañadas que fueron inhibidas por el ejercicio de natación. En comparación con los grupos control, HFD causó un aumento en el IMC y el peso del hígado, pero no en el índice de hígado. Además, HFD aumentó significativamente (p <0.05) los biomarcadores de lesiones hepáticas; la proteína C reactiva de alta sensibilidad (hsCRP) y la fosfatasa alcalina (ALP) disminuyeron efectivamente (p <0.05) con el ejercicio de natación. Además, se observó una correlación negativa entre estos biomarcadores y la proteína antioxidante y antiinflamatoria adiponectina. Por lo tanto, la esteatosis hepática inducida por HFD puede ser tratada mediante el ejercicio de natación.

Effects of Dietary Fatty Acid Composition on Pro -and Macro -Glycogen Utilization and Resynthesis in Rat Skeletal Muscle

The purpose of this study was to investigate that the effect of dietary fatty acid composition on pro- and macro-glycogen utilization and resynthesis. The analyses were further extended for different muscle fibers (type I, type II, & type IIb ) as well as tissues (i.e., liver & heart ). Total one hundred sixty Sprague-Dawley rats were used, and rats were randomly allocated into four experimental groups :animals fed standard chow diet (n =40 ), animals fed saturated fatty acid diet (n =40 ), animals fed monounsaturated fatty acid (n =40 ), and animals fed polyunsaturated fatty acid (n =40 ). Animals in each groups were further divided into five subgroups :sacrificed at REST (n =8 ), sacrificed at immediately after 3 hr swim exercise (P-0HR, n =8 ), sacrificed at one hour after 3 hr swim exercise (P-1HR, n =8 ), sacrificed at four hour after 3 hr swim exercise (P-4HR, n =8 ), and sacrificed at twenty-four hour after 3 hr swim exercise (P-24HR, n =8 ). Soleus (type I ), red gastrocnemius (type IIa ), white gastrocnemius (type IIb ), liver, and heart were dissected out at appropriated time point from all animals, and were used for analyses of pro- & macro-glycogen concentrations. After 8 weeks of dietary interventions, there was no significant difference in body mass in any of dietary conditions (p >.05 ). After 3 hr swim exercise, blood lactate level was higher compared to resting conditions in all groups, but it was returned to resting value after 1 hr rest (p .05 ). Regardless of forms of glycogen, the highest level was observed in liver (p <.01 ), and most cases of supercompensation after 3hr exercise observed in this study were occurred in CHOW fed tissues. Except heart muscle, all tissues used in this study showed that pro- and macro-glycogen concentration was significantly decreased after 3 hr exercise. Based on these results, two conclusions were made :first, there is no different level of glycogen content in various tissues regardless of types of fatty acids consumed and second, the highest mobilization rate would be demon-strated from CHOW fed animals compare to animals that consumed any kinds of fatty acid diet if prolonged exercise is applied.