The role of cyclooxygenase-2 on endurance exercise training in female LDL-receptor knockout ovariectomized mice

Evaluation of Collagen Fibers, MMP2, MMP9, 8-OHdG and Apoptosis in the Aorta of Ovariectomized LDL Knockout Mice Submitted to Aerobic Exercise

Background

In menopause, there is greater cellular exposure to oxidative stress, related to the decreased antioxidative effects of estrogen. These metabolic changes favor the progression of cardiovascular diseases, such as atherosclerosis. Abnormal function of the aorta - the most important artery - is associated with many cardiovascular diseases. Collagen, especially types I and III, is one of the most important aortic wall components and it can be affected by many factors, including menopause. The 8-OHdG is one of the main markers of DNA oxidative damage induced by reactive oxygen species (ROS).

Objective

We aimed to investigate effects of moderate aerobic training on the ascending aorta of LDL-knockout (LDL-KO) and ovariectomized female mice.

Methods

A total of 15 C57BL/6 mice and 15 LDL-KO mice were divided into experimental groups. The thickness and volume density of types I and III collagen fibers were performed by morphoquantitative analysis, whereas the MMP-2 and MMP-9 and 8-OHdG were detected by immunohistochemistry and apoptosis was detected by the TUNEL assay. The significance level for all tests was p < 0.05.

Results

Exercise causes an increase in the thickness of the aorta in LDL-KO groups, particularly accentuated in the ovariectomized groups. The type I collagen fibers showed an increase in volume density influenced by training in both Control groups and in the LDL-KO group. Type III collagen density decreased in both groups. The MMP-2 showed moderade immunostaining in the tunica media in LDL-KO groups, which did not occur in the control groups and the MMP-9 stained irregularly in all tissues. The marker 8-OhdG was stronger in the exercise training groups. Additionally, the ovariectomy, the exercise training and the LDL-KO treatments increased apoptosis.

Conclusion

These results suggest that moderate-intensity aerobic exercise in ovariectomized mice associated to an increase in LDL rate possibly increases oxidative stress and apoptosis induction.

Effects of moderate exercise on biochemical, morphological, and physiological parameters of the pancreas of female mice with estrogen deprivation and dyslipidemia

Menopausal women are at high risk of developing heart disease. However, physical exercise practice can reverse this scenario. We evaluated the biochemical, morphological, and physiological effects of moderate aerobic physical exercise on the pancreas of knockout mice for LDL receptor with estrogen deprivation by ovariectomy. Animals were divided into six groups (n = 5): sedentary non-ovariectomized control; sedentary ovariectomized control; trained ovariectomized control; sedentary non-ovariectomized LDL-R knockout; sedentary ovariectomized LDL-R knockout; and trained ovariectomized LDL-R knockout. Physical exercise practice promoted improvement in biometric and biochemical parameters analyzed, with reduction of visceral adipose tissue and VLDL, triglycerides, total cholesterol, and blood glucose levels. In addition, physical exercise practice altered the morphology of pancreatic islets and improved their response to the effects of menopause. Thus, physical exercise practice was fundamental to minimize the effects of dyslipidemia associated with ovariectomy in the pancreatic tissue of LDL-R knockout animals, contributing to reduce the risk of developing cardiac diseases in the menopause period.

Effects of Six Weeks Endurance Training and Aloe Vera Supplementation on COX-2 and VEGF Levels in Mice with Breast Cancer

The aim of this study was to determine effects of six weeks endurance training and Aloe Vera supplementation on COX-2 and VEGF levels in mice with breast cancer. For this purpose, 35 rats were randomly divided into 5 groups: control (healthy) and 4 cancer groups: control (cancer only), training, Aloe Vera and Aloe Vera + training. Breast cancer tumors were generated in mice by implantind. The training program comprised six weeks of swimming training accomplished in three sessions per week. Training time started with 10 minutes on the first day and increased to 60 minutes in the second week and the water flow rate was increased from 7 to 15 liters per minute at a constant rate. Aloe Vera extract at a dose of 300 mg/kg BW was administrated to rats by intraperitoneal injection. At the end of the study period, rats were anesthetized and blood samples were taken. Significant differences were concluded at p<0.05 with Kolmogorov-Smirnov and Tukey tests to analyze the data. The results showed significant increase in levels of serum. COX-2 and VEGF levels in the cancer group compared with the healthy group. Administration of Aloe Vera extract caused significant decrease in the COX-2 level in the cancer group. Also, in the training (swimming exercise) and Aloe Vera + training cancer groups, we observed significant decrease in the VEGF level as compared to controls. Our results suggest that Aloe Vera and training inhibit the COX pathway and cause decrease production of prostaglandin E2. Hence administration of Aloe Vera in combination with endurance training might synergistically improve the host milieu in mice bearing breast cancers.

Experimental studies of the molecular pathways regulated by exercise and resveratrol in heart, skeletal muscle and the vasculature

Regular exercise contributes to healthy aging and the prevention of chronic disease. Recent research has focused on the development of molecules, such as resveratrol, that activate similar metabolic and stress response pathways as exercise training. In this review, we describe the effects of exercise training and resveratrol on some of the organs and tissues that act in concert to transport oxygen throughout the body. In particular, we focus on animal studies that investigate the molecular signaling pathways induced by these interventions. We also compare and contrast the effects of exercise and resveratrol in diseased states.