Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology最新文献

Objective: To investigate the effects of aerobic intermittent exercise on the expressions of KLF15/mTOR related proteins to improve skeletal muscle lesions in type 2 diabetes rats. Methods: The experimental model of type 2 diabetes rats was established by feeding high-fat diet for 4 weeks and intraperitoneal injection of streptozotocin (STZ). After modeling, rats were randomly divided into two groups: diabetes model group (DM), diabetes+exercise group (DE), and normal rats were set as control group (C), 10 rats in each group. Group DE was given 8-week aerobic intermittent treadmill exercise intervention, while group C was not given any intervention. At the end of the experiment, the expressions of KLF15, mTOR, p-mTOR, and cleared caspase-3 in gastrocnemius muscle were detected by Western blot. The histopathologic changes of gastrocnemius were observed under microscope; skeletal muscle cells apoptosis rates and muscle mass were examined respectively using HE staining and TUNEL fluorescence staining. At the same time, changes of blood glucose and serum insulin, and weight were examined in the end of the experiment. Results: ①Compared with group C, the wet weight of gastrocnemius muscle and body weight, ratio of wet gastrocnemius muscle and body weight in group DM were decreased(P＜0.05 or P＜0.01); compared with group DM, the wet weight of gastrocnemius muscle, ratio of wet gastrocnemius muscle and body weight in the group DE were increased significantly (P＜0.05). ②Compared with group C, the fasting blood glucose level of group DM was increased significantly (P＜0.01), while serum insulin level of the group DM was decreased significantly(P＜0.01);compared with group DM, the above indexes were opposite in the group DE with intervention(P＜0.05). ③Compared with group C, the morphology of skeletal muscle cells in group DM was abnormal, the number of muscle nuclei was increased, the transverse lines were blurred and disappeared, the sarcomere was broken, and some muscle fibers were dissolved. Compared with group DM, the abnormal cell morphology, segmental injury of sarcomere and dissolution of muscle fibers in group DE were improved. The sarcolemma was more complete and the arrangement of muscle nuclei was more orderly. ④Compared with group C, the expressions of KLF15 and cleaved caspase-3, cells apoptosis rates in group DM were increased significantly(P＜0.01), while p-mTOR/mTOR level was decreased(P＜0.01) ; compared with group DM, the above indexes were opposite in the group with intervention(P＜0.05 or P＜0.01). Conclusion: Aerobic intermittent exercise is beneficial to improve the skeletal muscle pathological changes in type 2 diabetes rats, which may be due to the effective regulation of KLF15/mTOR related protein expression and the reduction of apoptosis damage.

Objective: To investigate the protective effects of erythropoietin derived peptide, also known as spiral B surface peptide (HBSP), on kidney and aggregated proteins (Agrin) levels in acute skeletal muscle strain rats. Methods: Forty SPF grade SD male rats were randomly divided into control group, injury group, HBSP group and EPO group, with 10 rats in each group. Acute skeletal muscle strain animal models were established except the control group. After successful modeling, the rats in HBSP group and EPO group were intraperitoneally injected with 60 μg/kg HBSP and 5 000 U/kg recombinant human erythropoietin (rhEPO), and the rats in the control group and the injured group were intraperitoneally injected with 0.9% normal saline. Renal function was monitored with relevant kits; Hematoxylin-eosin staining was used to observe the pathological morphology of kidney tissue and skeletal muscle strain tissue. The apoptosis rate of renal tissue cells was detected by in situ terminal transferase labeling (TUNEL). Western blot and quantitative polymerase chain reaction (Q-PCR) were used to determine the expressions of Agrin and muscular-specific kinase (MuSK) in the injured skeletal muscle of rats in each group. Results: Compared with the control group, the renal function indexes serum creatinine (Cr), urea nitrogen (BUN) and 24 h urinary protein (UP24) levels of rats in injured group were increased (P＜ 0.05), but the levels of BUN, Cr and UP24 of rats in HBSP group were decreased (P＜0.05). Compared with HBSP group, there were no significant differences in the above indexes in EPO group (P＞0.05). In the control group, the muscle fiber structure was intact, the shape and structure of the fiber bundles were normal, and there was no infiltration of red blood cells and inflammatory cells in the interstitium, and no fibrohyperplasia. In the injured group, the muscle tissue showed sparse and irregular arrangement, and the interstitial widened with a large number of inflammatory cells and red blood cell infiltration. Erythrocytes and inflammatory cells were reduced in HBSP group and EPO group, and the transverse and longitudinal lines of muscle were clear. The glomerular structure of the rats in the fibrohyperplasia control group was intact and no lesions were observed. In the injured group, glomerular hypertrophy and significant matrix hyperplasia were observed, as well as the expansion of renal cysts with vacuolar and significant inflammatory infiltration were observed, and the inflammatory infiltration was reduced in the HBSP and EPO groups. Glomerular hypertrophy and hyperplasia were alleviated. The apoptosis rates of kidney cells in control group, injured group, HBSP group and EPO group were (4.05±0.51) %, (26.30±2.05) %, (14.28±1.62) % and (16.03±1.77) %, respectively, and there were significant differences among these groups (P＜0.05). Compared with control group, the levels of Agrin and MuSK in skeletal m

Objective: To investigate the effects of panax notoginseng saponins (PNS) on pulmonary vascular remodeling and SIRT1/FOXO3a/p27 pathway in pulmonary arterial hypertension (PAH) rats. Methods: Male SD rats weighing 200~250g were randomly divided into control group, monocrotaline group (MCT) and monocrotaline + panax notoginseng saponins group (MCT+PNS), with 10 rats in each group. The rats in control group were injected intraperitoneally with normal saline 3 ml/kg on the first day, then injected intraperitoneally with normal saline 2.5 ml/kg every day. The rats in MCT group were injected intraperitoneally with MCT 60 mg/kg on the first day, followed by daily injection of normal saline 2.5 ml/kg. In MCT+PNS group, 60 mg/kg MCT was injected intraperitoneally on the first day, and 50 mg/kg PNS was injected intraperitoneally every day. The above models were fed conventionally for 4 weeks. After the modeling was completed, the mean pulmonary artery pressure (mPAP) and right ventricular systolic pressure (RVSP) of rats in each group were detected by right heart catheter method, weighed and calculated right ventricular hypertrophy index (RVHI), and the pulmonary vascular structure and morphological changes were observed by HE and Masson staining. The protein and gene expressions of SIRT1, FOXO3a, p27, PCNA and Caspase-3 were detected by qPCR and Western blot. Results: Compared with control group, mPAP, RVSP and RVHI in MCT group were increased significantly (P＜0.01), pulmonary vessels were thickened significantly and collagen fibers were increased, protein and gene expressions of SIRT1, FOXO3a, p27 and Caspase-3 were decreased (P＜0.05 or P＜0.01). The protein and gene expressions of PCNA were increased (P＜0.05). Compared with MCT group, the levels of mPAP, RVSP and RVHI in MCT+PNS group were decreased significantly (P＜0.05 or P＜0.01), pulmonary vascular thickening was alleviated and collagen fibers were reduced. The protein and gene expressions of SIRT1, FOXO3a, p27 and Caspase-3 were increased (P＜0.05 or P＜0.01), while the protein and gene expressions of PCNA were decreased (P＜0.05 or P＜0.01). Conclusion: Panax notoginseng saponins can relieve pulmonary vascular remodeling in rats with pulmonary hypertension by activating SIRT1/FOXO3a/p27 pathway.

Objective: To study the protective effects of resveratrol (RSV) on cardiac function in rats with high altitude hypobaric hypoxia and its mechanisms. Methods: Thirty-six rats were randomly divided into control group, hypobaric hypoxia group (HH) and hypobaric hypoxia + RSV group (HH+RSV) according to the random number, 12 rats in each group. Rats in the HH and HH+RSV groups were subjected to chronic long-term high altitude hypobaric hypoxia intervention for 8 weeks in a hypobaric chamber at a simulated altitude of 6 000 m for 20 h / d. The rats of HH + RSV were fed with RSV at a dose of 400 mg/(kg·d). The rats were tested once a week for body weight and twice a week for food intake. Before execution, the rats were tested by blood cell analyzer for routine blood parameters and echocardiogram for cardiac function parameters in each group. The routine blood indexes of each group were measured by blood cell analyzer, the cardiac function indexes of each group were measured by echocardiography, myocardial hypertrophy was evaluated by HE staining, myocardial tissue reactive oxygen levels were evaluated by dihydroethidium (DHE) staining. Oxidative stress was evaluated by serum and myocardial tissue total antioxidant capacity (T-AOC), superoxide dismutase activity (SOD) and malondialdehyde (MDA) content. Results: Compared with the C group, the body mass and food intake of rats were decreased significantly (P＜0.05) in HH group, while compared with the C group, RSV had no significant effects on the body mass and food intake of rats in the HH+RSV group (P＞0.05). Compared with the C group, the levels of erythrocytes and hemoglobin of rats in the HH group were increased significantly (P＜0.05), while the platelet concentration was decreased significantly(P＜0.05); compared with the HH group, the erythrocyte and hemoglobin levels were decreased significantly (P＜0.05) and platelet concentration was increased significantly(P＜0.05) in rats of the HH+RSV group. Compared with the C group, the cardiac coefficient, myocardial fiber diameter and thickness were significantly increased in the HH group (P＜0.05); compared with the HH group, the cardiac coefficient and myocardial fiber thickness were significantly decreased in the HH+RSV group (P＜0.05). Echocardiographic analysis showed a significant increase in ventricular wall thickness (P＜0.05) and a significant decrease in ejection fraction and cardiac output (P＜0.05) in the HH group compared with the C group, and a significant decrease in ventricular wall thickness and a significant improvement in cardiac function (P＜0.05) in the HH+RSV group compared with the HH group. The results of DHE staining showed that myocardial tissue reactive oxygen levels were increased significantly in the HH group compared with the C group (P＜0.05); myocardial tissue reactive oxygen levels were significantly restored in the HH+RSV g

Objective: To investigate the effects of bosutinib on the malignant behavior of thyroid papillary carcinoma B-CPAP cells and its possible mechanisms. Methods: Thyroid papillary carcinoma B-CPAP cells were cultured in vitro with a concentration gradient of(1、2、3、4 and 5 μmol/L)bosutinib intervened for 24 hours, DMSO was used as the control group. Five parallel compound holes were set in each group. Cell counting kit (CCK-8 method) method was used to detect cell proliferation. Transwell assay and cell wound healing assay were used to detect cell invasion and migration. TUNEL staining assay and flow cytometry were used to detect cell apoptosis. Western blot was used to detect the expressions of autophagic proteins (Beclin-1, LC3, p62) and signal pathway proteins (SIK2, p-mTOR, mTOR, p-ULK1, ULK1). Results: Compared with the control group, the cell proliferation activity, migration ability and invasion ability were decreased (P＜0.01), while the cell apoptosis rate was increased (P＜0.01) in the bosutinib concentration groups of 2, 3, 4 and 5 μmol/L . In the concentration groups of 4 and 5 μmol/L, the expression of Beclin-1 (P＜0.05), LC3- Ⅱ/LC3- Ⅰ (P＜0.05), SIK2 (P＜0.01) and p-ULK1 (P＜0.01) protein was decreased, while the expression of p62 (P＜ 0.05) and p-mTOR (P＜0.01) protein was increased. Conclusion: Bosutinib may inhibit the autophagy of thyroid papillary carcinoma cells through SIK2-mTOR-ULK1 signaling pathway to inhibit their proliferation, invasion and migration and promote apoptosis, thereby weakening their malignant behavior.

Objective: To investigate the intervention effects of curcumin (Curc) on liver injury induced by chronic alcohol addiction in mice. Methods: Thirty Balb/c mice were randomly divided into normal control group (Control), model group (Model), low-dose Curc group (5 mg/kg, Curc-L), medium dose Curc group (10 mg/kg, Curc-M) and high-dose Curc group (15 mg/kg, Curc-H), with 6 mice in each group. The chronic alcohol addiction liver injury model was prepared with 20% liquor. The mice in control group were given 2 ml of normal saline every day. The mice in model group were given 5 ml/kg of 20% liquor every day, and the mice in Curc treatment group were treated with Curc at the doses of 5, 10, 15 mg/kg in 2 ml saline every day for 35 days. The weight of liver was measured and the health status of mice was observed. Serum ALT, AST, ALP and liver TG, TC, HDL-C, LDL-C, MDA, SOD, GSH-Px and NO were measured. The pathological changes of liver tissues stained with hematoxylin and eosin were observed. Results: Compared with the control group, the liver mass and serum levels of ALT, AST, ALP, MDA, NO, TC, TG, HDL-C, LDL-C in the model group were increased significantly (P＜0.05, P＜0.01), the activities of SOD and GSH-Px were decreased significantly (P＜0.05, P＜0.01), the liver cells were vacuolated and infiltrated with inflammatory cells, and the expression levels of NF-κB and MAPK protein in liver tissues were increased significantly (P＜0.01). Compared with the model group, the levels of ALT, AST, ALP, MDA, NO, TC, TG, HDL-C, LDL-C in Curc group were decreased significantly nd the activities of SOD and GSH-Px were increased significantly (P＜0.05, P＜0.01). Conclusion: Curc can effectively reduce liver tissue damage by regulating NF-κB/MAPK signal pathway.

Objective: To investigate the effect of SIX2 gene on the proliferation of bovine skeletal muscle satellite cells. Methods: Bovine skeletal muscle satellite cells were used as experimental materials, and the expression of SIX2 gene in bovine skeletal muscle satellite cells was detected by real-time quantitative PCR at 24 h, 48 h, and 72 h of proliferation. The SIX2 gene overexpression vector was constructed by homologous recombination. The SIX2 gene overexpression plasmid and the control empty plasmid were transfected into bovine skeletal muscle satellite cells, and each group had three complex Wells. The cell viability was detected by MTT assay at 24 h, 48 h and 72 h after transfection. At 48 h after transfection, the cell cycle was detected by flow cytometry, and the expressions of cell proliferation marker genes were detected by real-time quantitative PCR (qRT-PCR) and Western blot. Results: With the proliferation of bovine skeletal muscle satellite cells, the expression of SIX2 mRNA was increased. Compared with the control group, the expressions of SIX2 mRNA and protein in the SIX2 gene overexpression plasmid group were increased by 18 and 2.6 times, respectively (P＜0.01). The cell viability of the SIX2 gene overexpression plasmid group was increased (P＜0.01), the proportion of G1 cells was decreased by 24.6%, and the proportion of S phase and G2 phase cells was increased by 20.3% and 4.31%, respectively (P＜0.01). The mRNA and protein expressions of Pax7 gene were increased by 15.84 and 1.22 times, respectively, and the mRNA and protein expressions of proliferation marker genes PCNA and CCNB1 were increased by 4.82, 2.23,1.55 and 1.46 times, respectively (P＜0.01). Conclusion: Overexpression of SIX2 gene promotes the proliferation of bovine skeletal muscle satellite cells.

Objective: To investigate the effects of repeated sevoflurane exposure on hippocampal cell apoptosis and long-term learning and memory ability in neonatal rats and its regulation on PI3K/AKT pathway. Methods: Ninety SD rats were randomly divided into the control group (25% oxygen), the single exposure group (inhalation of 3% sevoflurane and 25% oxygen on the 6th day after birth), the 3-times exposure group (inhalation of 3% sevoflurane and 25% oxygen on the 6th, 7th, and 8th day after birth), the 5-times exposure group (inhalation of 3% sevoflurane and 25% oxygen on the 6th, 7th, 8th, 9th and 10th day after birth), and the 5-times exposure + 740Y-P (PI3K activator) group (intraperitoneal injection of 0.02 mg/kg 740Y-P after inhalation of sevoflurane for 5 times) according to the random number table method. Morris water maze was used to measure the learning and memory ability; HE staining and transmission electron microscopy were used to observe the morphological and structural changes of neurons in the hippocampus; TUNEL was used to detect the apoptosis of hippocampal nerve cells; Western blot was used to detect the expressions of apoptosis-related proteins (Caspase-3, Bax, Bcl-2) and PI3K/AKT pathway related proteins in the hippocampus of rats. Results: Compared with the control group and the single exposure group, the learning and memory abilities of rats in the 3-times exposure group and the 5-times exposure group were severely reduced, the morphology and structure of hippocampal neurons were severely damaged, and the apoptosis rate of hippocampal nerve cells was increased (P＜0.05), the expressions of Capase-3 and Bax proteins were significantly increased (P＜0.05), and the expressions of Bcl-2 protein and PI3K/AKT pathway protein were significantly decreased (P＜0.05). With the increase in the number of exposures to sevoflurane, the learning and memory abilities of rats were significantly reduced, the hippocampal neuron cells were severely damaged, the hippocampal neuronal apoptosis rate was significantly increased (P＜0.05), and the expressions of PI3K/AKT pathway proteins were significantly reduced (P＜0.05). Compared with the 5-times exposure group, the learning and memory abilities and hippocampal neuron structure of rats in the 5-times exposure +740Y-P group were restored to a certain extent, and the hippocampal neuronal apoptosis rate, the levels of capase-3 and Bax protein were significantly reduced (P＜0.05), while the expressions of Bcl-2 protein and PI3K/AKT pathway protein were increased significantly (P＜0.05). Conclusion: Repeated exposure to sevoflurane can significantly reduce the learning and memory abilities of neonatal rats and exacerbate hippocampal neuronal apoptosis, which may be mediated by inhibiting the PI3K/AKT pathway.

Objective: To investigate the alleviating effect of hydrogen (H₂) on homocysteine (Hcy) levels and non alcoholic fatty liver in rats with hyperhomocysteinemia (HHcy). Methods: After one week of adaptive feeding, Wistar rats were randomly divided into three groups: the general diet group (CHOW), the high methionine group (HMD), and the high methionine plus hydrogen rich water group (HMD+HRW), with 8 rats in each group. The CHOW group was fed with AIN-93G feed, while the HMD and HMD+HRW groups were fed with AIN-93G+2% methionine feed to construct an HHcy model. The HMD+HRW group was also gavaged with hydrogen rich water (3 ml/animal, twice a day, with a hydrogen concentration of 0.8 mmol/L), and body weight data were recorded. After 6 weeks of feeding, the plasma and liver samples were processed and collected. The plasma homocysteine (Hcy) and lipid contents of each group were measured, and the histological morphology of the liver was observed. The activities of key enzymes in the Hcy metabolism pathway and mRNA expression were detected in the liver. Results: Compared with the CHOW group rats, the Hcy level in the blood of HMD rats was significantly increased significantly (P＜0.05). Pathological tissue sections showed liver enlargement, injury, and fatty liver in the rats; Compared with the HMD group rats, the HMD+HRW group rats showed a significant decrease in Hcy in the blood, reduced liver damage, and increased Hcy metabolism key enzyme activity and mRNA expression in the liver, with statistical differences (P＜0.05). Conclusion: Hydrogen has a significant improvement effect on liver injury induced by HMD diet in HHcy rats, possibly by enhancing the three metabolic pathways of Hcy to reduce excessive Hcy in the body, thereby improving liver metabolic function and symptoms of non-alcoholic fatty liver disease.