BACKGROUND:There are many reports on the effects of low-to-moderate intensity endurance exercise on mitochondrial biogenesis in the skeletal muscle, but there is no understanding about the high-intensity endurance exercise. It has not been reported whether the high-intensity endurance exercise influence the mitochondrial biogenesis in the skeletal muscle through 5′-adenosine monophosphate-activated protein kinase (AMPK)/silent information regulator factor 2 related enzyme 1 (SIRT1) signal molecules. OBJECTIVE: To investigate the effect of AMPK/SIRT1 signaling cascade on the mitochondrial biogenesis in the skeletal muscle during different intensities of endurance exercises. METHODS:Forty-two male Sprague-Dawley rats were randomly divided into sedentary group, moderate-intensity exercise group and high-intensity exercise group. Moderate-intensity exercise load was 28 m/min, 60 min/d;high-intensity exercise load was 38 m/min, 60 min/d. In both exercise groups, the rats had 5 days of exercise and 2 days of rest within 1 week, and the exercise lasted for totaly 7 weeks. The animals of exercise groups were kiled immediately, 6 hours and 24 hours after exercise. Quantitative PCR was used to detect peroxisome proliferators γ activated receptor coativator-1α (PGC-1α) and SIRT1 gene expression, and western blot to detect phosphorylated-AMPK (P-AMPK) and SIRT1 protein expression. RESULTS AND CONCLUSION:(1) Immediately, 6 hours, 24 hours after moderate-intensity exercise, PGC-1α mRNA expression in the skeletal muscle was 362% (P < 0.01), 675% (P < 0.01) and 116% of that in the sedentary group, P-AMPK protein expression was 112%, 165% (P < 0.05), 129% (P < 0.05) of that in the sedentary group, the expressions of SIRT1 protein and mRNA were 55% (P < 0.05), 86%, 103% and 109% (P < 0.05), 155%, 132% (P < 0.05) of those in the the sedentary group, respectively. (2) Immediately, 6 hours, 24 hours after high-intensity exercise, PGC-1α mRNA expression in the skeletal muscle was 274% (P < 0.01), 130% (P < 0.05), 68% (P < 0.05) of that in the sedentary group, the expression of P-AMPK protein was 235% (P < 0.01), 166% (P < 0.05), 160% (P < 0.05) of that in the sedentary group, the expressions of SIRT1 protein and mRNA were 199% (P < 0.01), 166% (P < 0.05), 164% (P < 0.05) and 255% (P < 0.01), 292% (P < 0.01), 122% of those in the sedentary group, respectively. These findings indicate that (1) 7 weeks of moderate-intensity endurance exercise significantly increased PGC-1α gene expression in the skeletal muscle, and its mechanism may involve AMPK/SIRT1 signaling cascade; (2) 7 weeks of high-intensity endurance exercise significantly inhibited PGC-1α gene expression at 24 hours after exercise,and this process was carried out in an AMPK/SIRT1 signal cascade independent manner.

Cardiovascular Diseases ; prevention & control ; Humans ; Thioredoxins

Objective:To investigate the relationship of the acute radiation reactions of totalbody irradiation before hematopoietic stem cell transplantation with the different total and fractionated doses of irradiation.Methods:The clinical data of 48 patients who underwent 6 MV X-ray total body irradiation pretreatment from May 2015 to December 2019 in Shijiazhuang Ping'an Hospital before undergoing hematopoietic stem cell transplantation were retrospectively analyzed. The patients were divided into 8 Gy group (12 cases), 10 Gy group (31 cases) and 12 Gy group (5 cases) according to the total radiation dose, and divided into 4 Gy/f group (17 cases) and 5 Gy/f group (31 cases) according to the fractionated radiation dose. Acute radiation reactions in the oral mucosa, pharynx, salivary glands, upper gastrointestinal tract, lower gastrointestinal tract and lung of patients in each group after radiotherapy were summarized and compared.Results:Acute pharyngeal reaction in the total radiation dose of 8 Gy group showed that 11 cases (91.7%) were grade 0 and 1 case (8.3%) was grade 1; in the total radiation dose of 10 Gy group, 10 cases (32.3%) were grade 0, 13 cases (41.9%) were grade 1, 4 cases (12.9%) were grade 2, 3 cases (9.7%) were grade 3, and 1 case (3.2%) was grade 4; in the total radiation dose of 12 Gy group, 2 cases (40.0%) were grade 0, 1 case (20.0%) was grade 1, 1 case (20.0%) was grade 2, and 1 case (20.0%) was grade 3. The severity of acute pharyngeal radiation reaction in the total radiation dose of 8 Gy group was better than that in the 10 Gy and 12 Gy groups, and the difference was statistically significant ( χ2 = 11.338, P = 0.003); there was no significant difference in the incidence of acute radiation reactions in other parts (all P > 0.05). Acute pharyngeal radiation reaction in the fractionated radiation dose of 4 Gy/f group showed that 13 cases (76.5%) were grade 0, 2 case (11.8%) was grade 1, 1 case (5.9%) was grade 2, and 1 case (5.9%) was grade 3; in the 5 Gy/f group, 10 cases (32.3%) were grade 0, 13 cases (41.9%) were grade 1, 4 cases (12.9%) were grade 2, 3 cases (9.7%) were grade 3, and 1 case (3.2%) was grade 4. The severity of acute pharyngeal radiation reaction in the fractionated radiation dose 4 Gy/f group was better than that in the 5 Gy/f group, and the difference was statistically significant ( Z = -2.606, P = 0.009); there was no significant difference in the incidence of acute radiation reactions in other parts (all P > 0.05). Conclusion:The total dose of 8 Gy and fractionated dose of 4 Gy/f in the total body irradiation before hematopoietic stem cell transplantation can alleviate the acute pharyngeal radiation reaction.