Low-intensity Treadmill Exercise Promotes Rat Dorsal Wound Healing

In order to investigate the promoting effect of low-intensity treadmill exercise on rat dorsal wound healing and the mechanism, 20 Sprague-Dawley rats were randomly divided into two groups： exercise group（Ex） and non-exercise group（non-ex）. The rats in Ex group were given treadmill exercise for one month, and those in non-ex group raised on the same conditions without treadmill exercise. Both groups received dorsal wound operation with free access to food and water. By two-week continuous observation and recording of the wound area, the healing rate was analyzed. The blood sample was collected at day 14 post-operation via cardiac puncture for determination of the number of endothelial progenitor cells（EPCs） by flow cytometry, and the concentrations of relevant cytokines such as basic fibroblast growth factor（b FGF）, endothelial nitric oxide synthase（e NOS） and vascular endothelial growth factor（VEGF） were measured by ELISA. The skin tissue around the wound was dissected to observe the vascular density under the microscope after HE staining, to detect the m RNA level of VEGFR2 and angiopoietin-1（Ang-1） receptor using RT-q PCR, and protein expression of α-smooth muscle actin（αSMA） and type collagenⅢ（ColⅢ） using Western blotting. It was found that the wound area in Ex group was smaller at the same time point than in non-ex group. The number of circulating EPCs was greater and the concentrations of vasoactive factors such as VEGF, e NOS and b FGF were higher in Ex group than in non-ex group. HE staining displayed a higher vessel density in Ex group than in non-ex group. Moreover, the m RNA expression of VEGFR2 and Ang-1 detected in the wound tissue in Ex group was higher than in non-ex group. Meanwhile, the protein expression of αSMA and Col Ⅲwas more abundant in Ex group than in non-ex group. Conclusively, the above results demonstrate Ex rats had a higher wound healing rate, suggesting low-intensity treadmill exercise accelerates wound healing. The present work may provide some hint for future study of treating refractory wound.

Early Exercise Promotes Angiogenic Response in Mice Model of Myocardial Infarction

Objectives Little is known about the mechanism of exercise-induced angiogenic response in ischemic myocardium. This study was designed to investigate the effects of exercise training on expression of vascular endothelial growth factor and angiogenesis in infarcted heart. Methods Fifty male FVB mice were divided into three subgroups to test various responses to exercise, including time- dependent response of angiogenic factors to exercise training in intact heart (n=10) and infarcted heart (n= 10), as well as exercise-induced angiogenic response in heart with myocardial infarction (MI) (n=30). The mice in the exercise-training groups were allowed to exercise daily at 1 hour per day for 7 days. Results VEGF protein expression was up-regulated by exercise training in time dependent fashion in mice with MI. Angiogenesis was evident by increased myocardial mi- crovessels observed by PECAM-1 immunohistoc-hemi- cal staining in post-MI exercise group (16.5±3.4)/0.4 mm2 versus post-MI sedentary mice (10±2.1)/0.4 mm2 (P < 0.05). Cell proliferation assessment showed significantly higher (P < 0.05 ) number of BrdU positive cells in post MI mice in exercise group as opposed to sedentary post MI mice. 2%TTC staining disclosed a profound difference in the size of MI (18.25±2.93)% in exercise group vs sedentary group (29.26±7.64)% (P< 0.05). Conclusions Activation and up-regulation of VEGF in infarcted mice heart may contributes the angiogenic response to exercise training at the early stage of myocardial infarction. This underscores the impact of exercise on angiogenesis in post myocardial infarction setting.

The role of exercise in rehabilitation of discharged COVID-19 patients

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)mainly caused pneumonia and pulmonary fibrosis through upper respiratory tract infection,which resulted in acute respiratory distress syndrome(ARDS)and multiorgan damage of cardiovascular,nervous,digestive,and genitourinary systems.Although the virus test turned negative after the patient recovered,the damage to multiorgan caused by SARS-CoV-2 may irreversible.Therefore,the health status of the recovered patients has gradually become the focus of people's attention.Whether coronavirus disease 2019(COVID-19)patients can receive exercise rehabilitation training after discharge?and what's the basis?We try to analyze and answer these questions,will provide some ideas about the patients to develop a reasonable and effective exercise rehabilitation program.