Rat Mitochondria Research Articles

Structural and Functional Features of Ca2+ Transport Systems in Liver Mitochondria of Rats with Experimental Hyperthyroidism.

We analyzed structural and functional features of the main mitochondrial Ca2+-transporting systems, mitochondrial Ca2+ uniporter complex (MCUC) and Ca2+-dependent cyclosporin A-sensitive mitochondrial permeability transition pore (MPT pore), in rats with hyperthyroid state. It was found that, the rate of Ca2+ accumulation by rat liver mitochondria in this pathology increases by 1.3 times, which can be associated with higher level of the channel-forming subunit of the uniporter MCU and lower content of dominant-negative subunit of this complex MCUb. At the same time, the level of the regulatory subunit MICU1 remained unchanged. It was shown that calcium retention capacity of liver mitochondria in rats with experimental hyperthyroidism decreased by 2 times in comparison with the control, which attested to reduced resistance of liver mitochondria of hyperthyroid rats to induction of the MPT pore. The observed changes are consistent with the data on increased amount of cyclophilin D, a mitochondrial matrix peptidyl-prolyl isomerase that is known to modulate the MPT pore opening and expression of the Ppif gene that encodes mitochondrial cyclophilin D in rats with experimental hyperthyroidism.

Experimental assessment of carbacetam effect on the cerebral mitochondria in rats with scopolamine-induced Alzheimer’s disease

Experimental assessment of carbacetam effect on the cerebral mitochondria in rats with scopolamine-induced Alzheimer’s disease

41 Changes of Mitochondria-related Gene Expression Profile Associated with Burn-induced Cardiomyopathy

Abstract Introduction Burn-related cardiac mitochondria dysfunction (BRMD) is associated with negative health outcomes and decreased health-related quality of life; however, few studies of the molecular-genetic mechanisms of BRMD exist. Methods 60% of total body surface area (TBSA) burned rats was employed. O2K Respirometer system (Innsbruck, Austria) was utilized to measure cardiac mitochondrial function. OXPHOS complex activities were determined by using OXPHOS enzyme complex activity assays (Cayman Chemical, Ann Arbor, Michigan). The Rat Mitochondria RT2 Profiler PCR Array was used to identify differential regulation of genes involved in mitochondrial biogenesis and metabolism function. Results Burn injury induced cardiac mit dysfunction by decreasingOXPHOS oxygen consumption at State 3 energized by malate/pyruvate and succinate and declining mit ETC activity in complex I, III, IV and V. 84 rat mit-related gene profiles were measured. The mitochondrial gene profile showed that 30/84 genes related to mitochondrial function and structure were differentially expressed. Of these 30 genes, 17 (ATP12a, ATP4a, ATP6v0a2, ATP6v1e2, ATP6v1g3, COX8c, LHPP, NDUFA5, SLC25a10, SLC25a15, UCP1, UCP2, UCP3, UQCRFS1, LDHA and RGDC) were more than 2 fold up-regulated, and 13 (ATP5c1, ATP5i, ATP5L, COX17, COX6c, COX7a2, NDUFA8, NDUFB3, NDUFB7, NDUFB9, NDUFS4, NDUFS8, and UQCRB) were greater than 2-fold down-regulated. Furthermore, 8 genes (AIFM2, BCL2, FIS1, IMMP2L, MSTO1, SLC25A23, SLC25A37, SLC25A4) that had significant differentially expression were associated with heart dysfunction. Conclusions This study provides preliminary evidence that 30 mitochondrial function genes were significantly associated with burn-induced heart dysfunction in 24 hpb rats. Applicability of Research to Practice These findings elucidate possible pathways and early biomarkers for targeting novel interventions for burn-induced heart dysfunction.

Effect of Electroacupuncture on Platelet-derived Growth Factor and the Ultrastructure of Mitochondria in Rats with Diabetic Gastroparesis

ObjectiveTo observe the effect of electroacupuncture (EA) at the pressure points Zu San Li (ST36), San Yin Jiao (SP6) and Liang Men (ST21) on platelet-derived growth factor (PDGF) and the ultrastructure of mitochondria in rats with diabetic gastroparesis (DGP). MethodsSixty Sprague Dawley (SD) rats were randomly separated into a normal control group (NC, n = 10) and a modeling group (n = 50). Rats in the modeling group received an injection of 2% streptozotocin (STZ) and a high-fat and high-glucose diet for eight weeks to establish a DGP rat model. At the same time, blood glucose and a general symptom score were recorded every week. After modeling, 30 successfully modeled rats were randomly separated into the following groups: the DGP group (n = 10), the EA group (n = 10) and the metoclopramide (MP) group (n = 10). After three weeks of intervention, the gastrointestinal propulsive rate was measured by measuring the optical density (OD). The concentration of Ca2+ was determined by fluorescence immunoassay, and levels of serum insulin (INS) and PDGF were determined by ELISA. The ultrastructure of mitochondria was observed with transmission electron microscopy. Results(1) After intervention, levels of blood glucose and the general symptom score were greatly decreased in the EA group compared to the DGP group (P < 0.01). Compared with the DGP group, the gastric emptying rate and the intestinal propulsive rate of the EA group was significantly improved (P < 0.01), and there was no statistically significant difference between the EA and the NC groups. (2) Compared with the NC group, the levels of INS in the DGP group markedly decreased (P < 0.05), but there was no significant difference of INS levels between the EA and the MP groups. (3) Compared with the DGP group, the concentration of Ca2+ in the EA and the MP groups significantly increased (P < 0.01, P < 0.05, respectively). (4) Compared with the NC group, the average OD of PDGF in the DGP group was significantly higher (P < 0.01). Compared with the DGP group, levels of PDGF in the EA group increased significantly (P < 0.01). (5) There were abundant mitochondria with a clear structure and complete cristae in the NC group. However, in the DGP group, mitochondria were severely swollen, partly vacuolated, and cristae were either fractured, absent, or shortened. In the EA group, mitochondria were slightly swollen, with clear cristae. ConclusionsElectroacupuncture at the points Zu San Li (ST36), San Yin Jiao (SP6) and Liang Men (ST21) may improve gastric motility in DGP by up-regulating the amount of PDGF and improving the ultrastructure of mitochondria.

A combination extract of kaffir lime, galangal, and lemongrass maintains blood lipid profiles, hepatocytes, and liver mitochondria in rats with nonalcoholic steatohepatitis

Kaffir lime leaves and the rhizomes of galangal and lemongrass are the main ingredients in several Thai foods with desirable medicinal effects. Based on their beneficial activities, this study aimed to indicate the chemical properties and in vivo efficacy of a combination of the herbs at a 1:2:1 ratio in a water extract form. Its volatile constituents were analyzed by gas chromatography coupled with mass spectrometer, which mainly consists of eucalyptol, citronellal, and citral. Clinicohistopathological and electron microscopic studies demonstrated that the extract corrected blood cholesterol, LDL, HDL, and triglyceride levels similarly as simvastatin treatment in association with its antioxidative properties, as indicated by the levels of superoxide dismutase and malondialdehyde in serum and the increment of nuclear factor erythroid 2-related factor 2 levels in hepatocytes. Hepatitis was significantly less severe in rats fed the extract for 14 days than in simvastatin-treated rats. Regarding its immunomodulatory properties, the extract also accelerated hepatic resolution from steatohepatitis during hypercholesterolemia as indicated by the upregulation of vimentin, cytokeratin, and CD206+. Interestingly, liver mitochondria were also preserved in hypercholesterolemic rats treated with the extract in relation to their architecture and the expression of haloacid dehalogenase-like hydrolase domain-containing protein 3 as well as metabolic and energy regulators. Therefore, the study concluded that the water extract of kaffir lime leaves and the rhizomes of galangal and lemongrass has beneficial effects on blood cholesterol, the severity of steatohepatitis, and the maintenance of mitochondrial architecture via its antioxidative and immunomodulatory activities.

THE EFFECT OF MELATONIN ON THE ENERGY METABOLISM IN HEART OF DIABETIC RATS

The aim of this study was to determine the effect of melatonin on activity of pyruvate kinase (PK) and lactate dehydrogenase (LDH) in the heart tissue and on the activity of succinate dehydrogenase (SDG) and H+-ATPase in mitochondria of cardiomyocytes of rats with dexamethasone diabetes. Methods. The research was performed in compliance with the Rules of the work with test animals (1977) and the European Convention on the Protection of Vertebrate Animals used in experiments and other scientific purposes (18 March 1986). The experiments were carried out on 36 sexually mature male albino rats with the body mass 0.18 – 0.20 kg. The animals were divided into 3 groups:1) control group; 2) group with diabetes mellitus DM (BG level ≥ 8.0 mmol/l); 3) diabetic animals which were injected with melatonin. Melatonin (“Sigma”, USA) was injected intraperitoneally in a dose of 10 mg/kg of body weight daily over 13 days. Dexamethasone diabetes was evoked by daily subcutaneous administration of dexamethasone (solution for injection 4 mg / ml, KRKA, Slovenia) at a dose of 0.125 mg / kg body weight for 13 days (O.V. Stefanov, 2001). The mathematical model of the insulin-glucose correlation by the Homeostasis Model Assessment (HOMA) was used to evaluate the insulin resistance in the animals (D.R.Matthews et al., 1985). The blood was taken from the tail vein to evaluate the BG level using “OneTouchUltra” (“LifeScan”, USA). The rats were sacrificed on the 14th day of the experiments in accordance with the ethical treatment of animals. 5% homogenate was prepared from cold-isolated rat hearts on chilled 50 mM Tris-HCl buffer (pH = 7.4) with sucrose. Mitochondria were isolated by differential centrifugation. Enzyme activities in the mitochondrial fraction was determined by: succinate dehydrogenase (SDG) according to the method of Eshchenko N.D. et al. (1992), H + -ATP-ase - for Gabibiv M.M. (1986). Serum insulin content was determined using an automatic immunochemiluminescent analyzer (Snibe Co., Ltd, PRC) using a Maglumi test kit. The insulin resistance index (HOMA-IR) was calculated by the formula: HOMA-IR = (glucose (mmol / l) • insulin (mcU / ml)) / 22.5. To determine the enzymes activities by standart methods, heart muscle tissue was quickly removed, rinsed in saline, blotted, weighed and homogenized. Then the homogenate (5% in ice-cold 0.25 mM tris-HCl-buffer) was ultracentrifugated (10 min at 1500r/min) and the supernatant was used for measurements. Statistical analysis was performed using Statistica 10 (StatSoft Inc). Prior to analysis, Shapiro-Wilk test was used to assess the normality of the group data. According to the criterion, the samples distributions differed from normal distribution. Given these, use of the Mann-Whitney test was considered sufficient for valid conclusions to be made. Differences were considered to be statistically significant when P ≤ 0.05. Results. In the blood of all diabetic rats on the 14th day the glucose content exceeded 8.9 mmol / l, and the HOMA-IR index increased 7 times. According to results, we have obtained the activity of PK in the heart tissue of diabetic animals was 55% less than in control group. It can be explained by low uptake of glucose from the blood by heart muscle tissue in conditions of insulin resistance. Reduced glucose uptake by peripheral tissues, in turn, leads to a reduced rate of glucose metabolism. That means now substrate for next catabolic changes in glycolysis. The activity of LDH increases by 32% in the heart muscles of diabetic rats compared with the control values. We have found out that the activity of PK and LDH has become normalized by the introducing of melatonin in dose of 10 mg/kg of body weight. In the mitochondria of the animals with dexamethasone diabetes, the activity of SDG and H+ -ATPase is significantly lower than that in intact animals by 45 and 32%, respectively. Probably, melatonin enhances the uptake of glucose by heart muscles. The blood glucose content of diabetic rats, which were administered is not significantly different from that of the intact animals, and the HOMA-IR was 6.3 times lower than that of diabetic rats. The activity of SDG and H+-ATPase in the mitochondria of rats receiving both melatonin and dexamethasone does not differ from that of intact rats. Conclusion. A 14-day introduction of melatonin leads to a marked improvement of the state of carbohydrate metabolism as well as the energy metabolism in heart tissue that is accompanied by the normalization of the indices studied.

Influence of Age Factor on Respiratory Control of Isolated Cardiomyocytes and Mitochondria in Rats.

We studied the peculiarities of oxidative and substrate phosphorylation in isolated cardiomyocytes and myocardial mitochondria in 2- and 15-month-old rats. It was shown that age factor reduces the degree of oxidation and phosphorylation coupling both in cardiomyocytes and in mitochondria, which was associated with the decrease in the rate of consumption of energy resources.

Age-Related Changes in the Functional Indices of Cardiac Mitochondria in Chronic Alcohol Intoxication in Rats

The effect of chronic continuous consumption of 5 and 10% ethanol solutions for six months on the respiratory function and oxidant/antioxidant status in the cardiac mitochondria of rats of different gender and age is studied. A decrease in the rate of oxygen consumption by cardiomyocyte mitochondria under the V2, V3, and V4 metabolic conditions according to Chance during the activation of the respiratory chain complexes I, I + II, and II is observed in old animals (24-month-old) compared to young (11-month-old) rats. The level of the products of lipid peroxidation (LPO) (malondialdehyde) in the cardiomyocyte mitochondria increases, whereas the activity of the antioxidant enzymes (superoxide dismutase and glutathione peroxidase) decreases. Chronic alcoholization of 24-month-old rats of both genders results in a more pronounced decline in the activity of respiratory function of the cardiac mitochondria, disintegration of respiration and oxidative phosphorylation, reduced activity of antiradical protection enzymes, and an increase in the level of LPO products compared to younger rats.

Ca2+/Calmodulin-Dependent Protein Kinase II Regulation by Inhibitor 1 of Protein Phosphatase 1 Protects Against Myocardial Ischemia-Reperfusion Injury.

Ca2+/calmodulin-dependent protein kinase IIδ (CaMKIIδ) plays a vital role in cardiovascular system. However, the potential protective role of inhibitor 1 of protein phosphatase 1 (I1PP1), which can regulate CaMKII, on myocardial ischemia-reperfusion (I/R) injury remains unknown. In the present study, expression of CaMKIIδ variants was detected by quantitative real-time polymerase chain reaction. I1PP1 was overexpressed by pericardial injection of recombinant adenovirus. Two weeks later, rats were subjected to left anterior descending ligation for 30 minutes followed by reperfusion. Myocardial infarct size was assessed by Evans blue/triphenyl tetrazolium chloride staining. Serum creatine kinase (CK) and lactate dehydrogenase (LDH) activity as well as myocardial pathological structure were detected. CaMKII activity was evaluated by phosphorylation of phospholamban (PLB) and oxidation of CaMKII. Expression of dynamin-related protein 1 (DRP1) and optic atrophy 1 (OPA1) in the mitochondria was measured by Western blot. We found that CaMKIIδA and CaMKIIδB expression decreased, while the expression of CaMKIIδC increased after myocardial I/R. Moreover, after 30-minute ischemia followed by 6 hours of reperfusion, I1PP1 overexpression reduced myocardial infarct size, decreased serum CK and LDH activity, ameliorated myocardial pathological structure, inhibited PLB phosphorylation at Thr17, suppressed CaMKII oxidation, elevated CaMKIIδA and CaMKIIδB variants but reduced CaMKIIδC variants, attenuated myocardial oxidative stress, improved myocardial mitochondrial ultrastructure, increased mitochondrial number and mitochondrial DNA copy number, and decreased DRP1 but increased OPA1 protein expression from the mitochondria in rats. Thus, I1PP1 regulated CaMKII, protected mitochondrial function, reduced oxidative stress, and attenuated myocardial I/R injury.

Effects of Hydrogen Sulfide on Inflammatory Factors and Mitochondrial Energy Metabolic Disorders After Reperfusion Injury in Rats

Objective To explore the effect of hydrogen sulfide on inflammatory factors and energy metabolism of mitochondria after limbs reperfusion injury in rats. Methods Sixty rats were divided into three groups:sham operation group,control group(ischemia-reperfusion injury + saline group),and experimental group(ischemia-reperfusion injury + H2S group).Wistar rat models of limb ischemia-reperfusion injury were established.Skeletal muscle samples were collected to determine the levels of necrosis decomposition products [including myoglobin(MB),lipoprotein complex(LPC)and lipid peroxide(LPO)];blood samples were collected to determine the levels of interleukin(IL)-1,IL-6 and tumor necrosis factor-α(TNF-α);mitochondria were extracted for mitochondrial transmembrane potential measurement and ATP content detection.Statistical analysis was made on the test results. Results After ischemia reperfusion injury,the levels of MB,LPO,and LPC in skeletal muscle,liver,lung and renal tissues of the control group were significantly increased(MB:Pskeletal muscle =0.003,Pliver =0.001,Plung =0.001,Pkidney =0.001;LPO:Pskeletal muscle =0.001,Pliver =0.001,Plung =0.001,Pkidney =0.002;LPC:Pskeletal muscle =0.000,Pliver =0.002,Plung =0.002,Pkidney =0.003),and hydrogen sulfide treatment during ischemia reperfusion significantly inhibited the production of MB,LPO,and LPC(MB:Pskeletal muscle =0.021,Pliver =0.036,Plung =0.005;LPO:Pskeletal muscle =0.003,Pliver =0.008,Plung =0.010,Pkidney =0.015;LPC:Pskeletal muscle =0.002,Pliver =0.026,P lung =0.007,P kidney =0.006).Ischemia/reperfusion of lower extremity in rats resulted in increased levels of IL-1,IL-6,and TNF-α in the serum of rats,and the levels of IL-1,IL-6,and TNF-increased over time,with statistically significant differences in IL-1,IL-6,and TNF-α among groups at 3 h(IL-1:P3 h =0.019,P6 h =0.011,P9 h =0.009,$P_{12_{h}}$=0.008,and P15 h =0.002;IL-6:P3 h =0.026,P6 h =0.009,P9 h =0.002, $P_{12_{h}}$=0.002,P15 h =0.003;TNF-α:P3 h =0.002,P6 h =0.002,P9 h =0.005,$P_{12_{h}}$=0.002,P15 h =0.003).The levels of IL-1,IL-6,and TNF-α in serum were significantly inhibited during ischemia reperfusion(IL-1:P3 h =0.035,P6 h =0.039,P9 h =0.012,$P_{12_{h}}$=0.005,P15 h =0.006;IL-6:P3 h =0.042,P6 h =0.025,P9 h =0.023,$P_{12_{h}}$=0.006,P15 h =0.005;TNF-α:P3 h =0.005,P6 h =0.003,P9 h =0.022,$P_{12_{h}}$=0.005,P15 h =0.005),and such inhibitory effects became even more obvious over time.After limb ischemia and reperfusion in the control group,the mitochondrial transmembrane potential of skeletal muscle cells significantly decreased compared with that of the sham group(t=6.698;P=0.001).After hydrogen sulfide treatment,the mitochondrial membrane potential energy of the experimental group was significantly higher than that of the control group(t=7.507,P = 0.000).The ATP level in the mitochondria of ischemia reperfusion rats in the control group was significantly lower than that in the sham group(t=7.526,P = 0.000).The content of mitochondrial ATP in the experimental group was significantly higher than that in the control group after hydrogen sulfide treatment(t=8.604,P = 0.000). Conclusions Hydrogen sulfide can alleviate the injury of skeletal muscle and distal organs after limb ischemia-reperfusion and reduce local inflammatory reaction.In addition,it is valuable in alleviating mitochondrial transmembrane potential and energy metabolism disorders during reperfusion injury.

Effects of aminooxyacetic acid on hippocampal mitochondria in rats with chronic alcoholism: the analysis of learning and memory-related genes

The incidence of chronic alcoholism leading to central and peripheral nervous system damage has been increasing year-to-year. The purpose of this study is to explore the effects of aminooxyacetic acid on hippocampus mitochondria in rats with chronic alcoholism and analyze learning and memory-related genes. Sixty male Sprague Dawley rats were randomly divided into three groups. Except for the control group, each group was fed with the water containing (v/v) 6% alcohol for 28 days. After 14 days, rats in the treatment group were intraperitoneally injected daily for 14 days with aminooxyacetic acid. High throughput sequencing was combined and tested for learning and memory abilities, Hydrogen sulfide content, catalase activity in mitochondria, and the expression of F-actin in the hippocampus of the rats in each group. Compared with the control group, the learning and memory abilities of rats with chronic alcoholism were significantly impaired, mitochondria contained vacuoles, hydrogen sulfide increased, but catalase activity and F-actin content were significantly decreased, After treatment with aminooxyacetic acid, mitochondrial morphology improved, hydrogen sulfide content was decreased, while catalase activity and F-actin expression of in hippocampus were increased. This indicates that aminooxyacetic acid may improve learning and memory in rats with chronic alcoholism, and the mechanism is related to decreased hydrogen sulfide content and an increase of both catalase activity and F-actin level in the hippocampus, thereby reducing the damage of alcohol to mitochondria and neurons.

Rooibos tea (Aspalathus linearis) ameliorates the CCl4-induced injury to mitochondrial respiratory function and energy production in rat liver.

The rooibos tea (RT) is a source of valuable dietary dihydrochalcones  aspalathin, and nothofagin and other polyphenols. Many in vitro and in vivo studies have shown that RT flavonoids have strong antioxidant effect and significantly reduce oxidative stress. We investigated the antioxidant activity and protective effect of an aqueous extract of RT on the liver mitochondria oxidative phosphorylation in rats with carbon tetrachloride-induced (CCl4-induced) liver damage. Mitochondrial respiration and ATP production was determined amperometrically using a Clark-type oxygen electrode. We found significantly decreased parameters of oxidative phosphorylation in the group having received CCl4 for 10 weeks. Simultaneous administration of RT increased oxygen uptake stimulated with ADP, and the rate of ATP generation in the mitochondria of rats, both having been impaired in rats treated with CCl4 only. Treatment with RT significantly decreased CCl4-induced elevated enzyme levels, improved capacity of the respiratory chain and energy production, presumably due to its potent and direct antioxidant activity, including inhibition of mitochondrial lipid peroxidation. Improved histological features support the view of antioxidant and membrane-stabilizing activity of RT. This fact may play a significant role in the protection of the liver from injury caused by known toxins, and from subsequent development of steatosis and fibrosis..

Effects of High and Low Glycemic Load of Different Nigerian Food Forms on Rats Brain and Heart Mitochondrial Integrity

The present study was designed to investigate the effect of glycemic load (GL) on brain and cardiac mitochondrial integrity. The effect of high glycemic load (HGL) and low glycemic load (LGL) diets on the generation of free radicals and its consequent effect on brain and cardiac mitochondrial were assessed. The effect of the reactive oxygen species (ROS) on the activities of electron transport chain (ETC) was examined. A significant decline in enzyme activities of complex I, III and IV were observed, for both brain and cardiac mitochondria ETC. Brain rotenone-sensitive complex I activities decreased by 49.20% (p>0.05) in HGL-fed rats, while antimycin-a sensitive complex III decreased by 19.80% (p>0.05). Same phenomenon was observed in potassium cyanide (KCN)-sensitive complex IV (cytochrome c oxidase), which decreased by 30.17% (p>0.05). For cardiac mitochondrial complexes, Rotenone-sensitive complex I decreased by 25.45% (p>0.05) in HGL fed group, while antimycin-a sensitive complex III activity decreased by 24.78% (p>0.05). Glycemic related changes were also observed in KCN-sensitive complex IV with a decrease of 21.18% (p>0.05). Enzyme activities in both brain and cardiac mitochondrial homogenates decrease minimally in LGL fed rats, compared with the control. Thiol group content, total protein and malondialdehyde (MDA) were found to be significantly elevated in rats fed with HGL diet. Superoxide dismutase (SOD) and catalase (CAT) enzymes activities decreased in both brain and cardiac mitochondria of rats fed with HGL diets. It can be concluded that low glycemic load diet sustains the mitochondrial integrity. Whereas, HGL diets induced oxidative stress and degenerates antioxidant enzymes activities in brain and heart mitochondria; thereby inducing loss of mitochondrial integrity.

Age- and Tissue-Specific Calcium-Dependent Permeabilization of Rat Mitochondria by α,ω-Hexadecanedioic Acid

Age- and Tissue-Specific Calcium-Dependent Permeabilization of Rat Mitochondria by α,ω-Hexadecanedioic Acid

Effect of molecular hydrogen on coenzyme Q in plasma, myocardial tissue and mitochondria of rats

Effect of molecular hydrogen on coenzyme Q in plasma, myocardial tissue and mitochondria of rats

PO-084 Research of HIIT Detraining on Mitochondria of Soleus Muscle Beclin1 and Bnip3 Contents in Aging Rats

Objective To observe the temporal variation of Beclin1 and Bnip3 protein in skeletal muscle aging degeneration by constructing the aged rat model, and to observe the effect of HIIT intervention on the changes of Beclin1 and Bnip3 protein and the relationship between the two. It provides a theoretical basis for the effect of exercise on the aging degeneration of skeletal muscle by affecting the level of mitochondrial autophagy.&#x0D; Methods 40 male Wistar rats aged 8 months were randomly divided into quiet control group (C) and HIIT intervention group (H). After the rats entered the animal room for one week of adaptive feeding and exercise, the rats in the C group did not exercise, and the H group exercise alternately based on the maximum oxygen uptake test results of the rats with the 70%-90%-50%VO2max intensity. Once every two weeks, the maximal oxygen uptake of the rats in group H and group C was tested. Group H underwent 50min/ days, 5 days / weeks, and lasted for 16 weeks. The rats in the two groups were randomly selected after the first VO2 test and eighth and sixteenth weeks after intervention. After anesthesia, blood was collected from the abdominal aorta and soleus tissue was obtained. The ROS activity in soleus muscle was tested by fluorescence enzyme labeling method. Isolation of mitochondria from soleus muscle using tissue mitochondria Isolation Kit, and the expression of Beclin1 and Bnip3 in the mitochondria of the soleus muscle was tested by Western blot. The Image Lab 4 software was used to collect the data of the protein test strip, and the SPSS 17 software was used to analyze the data. The results of the data analysis were presented in the form of mean standard deviation. In the process of protein strip analysis, the relative value of the protein content of each sample was obtained by the gray scale analysis method. The results of the first sampling were taken as the baseline value, and the ratio of the H group in the C group of 8 weeks and 16 weeks was obtained with the baseline value, that is, the relative value of the protein content. Then, repeated measurement of variance analysis was used to analyze the differences of different indicators at baseline level, 8 weeks and 12 weeks between group C and group H. The independent sample T test was used without interaction effect, and multivariate analysis of variance was used. A significant level of alpha =0.05 is set.&#x0D; Results (1) the content of ROS in skeletal muscle of rats was related to the process of natural aging (F=119.314, P &lt; 0.001), and the level of ROS would rise with the process of natural collars (F=28.884, P=0.001; F=127.607, P &lt; 0.001) through the comparison of the time points in the group C and the H group. At the same time, the level of ROS in group H was lower than that in group C, but there was no significant difference (P=0.310). And the interaction effect of time and exercise mode (HIIT) will not affect the result (F=0.814, P=0.477). But the growth rate of ROS in group H was lower than that in C group. ⑵Exercise, time change and their interaction did not affect the content of Beclin1 in rat skeletal muscle mitochondria (P &gt; 0.05). ⑶The mitochondrial Bnip3 content in H group and C group was significantly different at 8 weeks (F=14.500, P=0.001), H group was significantly higher than that in C group, but there was no significant difference in mitochondrial Bnip3 content at the 16 week (F=0.090, P=0.767), and the Bnip3 content of skeletal muscle mitochondria changed with age (F=20.852, 0.001). The trend of H increased, but then decreased. There was a linear trend (F=6.950, P=0.005) between the level of mitochondrial Bnip3 content and the intergroup factors (time point changes) and the interaction between time and HIIT movement in rats.&#x0D; Conclusions With the process of aging, (1) The content of ROS in skeletal muscle of rats increased significantly, while long-term HIIT training could delay the increase, but the best exercise time was unknown. (2) There was no obvious change in Beclin1 content in skeletal muscle mitochondria of rats, and HIIT training had no obvious effect on it. However, the changes in mitochondrial Beclin1 content relative to the total Beclin1 content of skeletal muscle need to be further studied; (3) The content of Bnip3 in skeletal muscle mitochondria in rats is increased, and long-term HIIT training has a delayed effect.

Protective effect of electroacupuncture preconditioning at zúsānlĭ (足三里 ST36) on mitochondria in the intestinal ischemia/reperfusion injury

ObjectiveThe study explored the effect of applying electroacupuncture (EA) preconditioning at ST 36 on mitochondria in rats with intestinal ischemia/reperfusion injury. MethodsForty SD rats were divided into four sets: sham operation group (sham group); intestinal ischemia/reperfusion group (I/R group); EA preconditioning at ST 36 followed by intestinal ischemia/reperfusion injury (ST 36 + I/R group); EA preconditioning at the lateral site away from ST36 0.5 cm followed by intestinal ischemia/reperfusion injury (N + I/R group). For the sham group, the rats were opened abdominal cavity for 3 h and 20 min and their abdominal cavities were covered with wet gauze avoiding drying and kept on the thermostat at 37 °C. For the ischemia/reperfusion (I/R) group, rats were anaesthetised and their abdominal cavities were opened to expose jejunum segments. The segment's collateral blood supply was restricted by bilateral ligation of the intestine. Next, one of the branches of a mesenteric artery was occluded with a thread for 20 min and then the thread was released after such ischemia conditions, keeping reperfusion for 3 h. For the ST36 + I/R group, the electroacupuncture at ST36 was first performed, then the intestinal ischemia/reperfusion model was constructed. For the N + I/R group, electroacupuncture at non ST36 acupoint, which is away from ST36 about 0.5 cm, and then the intestinal ischemia/reperfusion model was performed. Measurements of the levels of inflammatory markers tumour necrosis factor α (TNFα) and interleukin-1 beta (IL-1β), cytochrome c (CYCS), and the mitochondrial membrane pro-apoptotic protein (BAX), anti-apoptotic protein Bcl-2 were performed. ResultsCompared to I/R group, the intensity of cytoplasmic CYCS in intestinal tissues was significantly decreased in the ST 36 + I/R group (1.65 vs. 0.18, p < 0.05). Compared to N + I/R group, the intensity of cytoplasmic CYCS in intestinal tissues was also dramatically declined in the ST 36 + I/R group (1.37 vs. 0.18, p < 0.05). The level of CYCS in mitochondria in rats in the ST 36 + I/R group were appreciably increased than those of rats in the I/Rgroup (1.42 vs. 0.06, p < 0.05), and CYCS in mitochondria was also largely expressed in ST36 + I/R group than N + I/R group (1.42 vs. 0.08, p < 0.05). Bcl-2 was shown to be elevated in the ST 36 + I/R group than I/R group (1.01 vs. 0.10) and N + I/R group (1.01 vs. 0.09, all p < 0.05), whereas BAX expression was greatly decreased in the ST36 + I/R group than I/R group (0.11 vs. 0.78 ) and N + I/R group (0.11 vs. 0.87, all p < 0.05). ConclusionThe results suggest the EA intervention has a protective effect upon mitochondria, preventing CYCS release and the subsequent activation of downstream apoptosis pathway. It is proposed that patients due to undergo gastrointestinal surgery get benefit from EA preconditioning at ST 36.

Effects of a high-fat diet on superoxide anion generation and membrane fluidity in liver mitochondria in rats

BackgroundObesity is a primary factor of lifestyle-related diseases, and the age of its onset has decreased. The reactive oxygen species (ROS), the superoxide anion, is generated in the mitochondrial electron transport chain and the damage it induces in cells may be a contributing factor to obesity-related lifestyle diseases. In the present study, the influence of the ingestion of a high-fat diet (HFD) on superoxide anion generation in rat liver mitochondria (Mt) and membrane fluidity was investigated.MethodsMale Wistar rats were fed a normal diet (ND, n = 6) or HFD (n = 6). Liver Mt were isolated and oxygen consumption, superoxide anion production (the adrenaline method), and membrane fluidity (the spin label method) were measured.ResultsAfter 11 weeks, body weights and abdominal circumferences were higher in the HFD group than in the ND group. Mt oxygen consumption was higher in the HFD group than in the ND group. Superoxide anion production was significantly lower in the HFD group than in the ND group, while no significant changes were observed in membrane fluidity.ConclusionAlthough rats developed diet-induced obesity, it did not reach the level of disease development. The promotion of lipid metabolism appeared to reduce superoxide anion production, but did not influence membrane fluidity. While superoxide anion damages cells as an oxidative stress, ROS and superoxide dismutase are essential signaling molecules in the body. The present results suggest that the continuous ingestion of a HFD impairs Mt and induces disease development.

Specific Features of Immediate Ultrastructural Changes in Brain Cortex Mitochondria of Rats with Different Tolerance to Hypoxia under Various Modes of Hypoxic Exposures.

We performed ultrastructural study of cerebral cortex mitochondria in rats with different tolerance to oxygen deficiency (low resistant and highly resistant specimens). Low resistant rats were characterized by the prevalence of mitochondria with lightened matrix due to the nondense packing of cristae. By contrast, mitochondria of highly resistant animals had the dense packing of cristae. The structure of mitochondria underwent adaptive changes at 14-10% O2 in the inspired air. Under these conditions, structural characteristics of the cerebral cortex in hypoxia-sensitive rats resembled those in resistant animals. The decrease in O2 concentration to 8% was accompanied by ultrastructural signs of mitochondrial damage, which correlated with de-energization of the cell and dysfunction of adaptive signaling systems. Ultrastructural features of cerebral cortex mitochondria in animals with low and high tolerance to acute oxygen deficiency confirm the hypothesis that they are associated with two different "functionaland-metabolic portraits".

Protective effect of Zanthoxylum armatum fruit on Heart Mitochondrial Antioxidants Against Isoproterenol Induced Cardiac Damage in Rats

Background: Mitochondria are prone to oxidative stress induced by chemicals and resulting in cardiac damage which can be ameliorated by the use of herbal drugs. Zanthoxylum armatum (Z. armatum) fruit are used as age-old herbal remedies. Their pharmacological and therapeutics actions are not exploited in detail. Objective: The present study is to analyze the antioxidants in the heart mitochondria of the rats challenged with isoproterenol hydrochloride (ISO) and the ameliorative effect of Z. armatum fruit. Method: The antioxidant effect of hydroethanolic extract of Z. armatum fruit on mitochondrial dysfunction induced by ISO in rats were appraised by studying the antioxidant enzymes namely superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST) and lipid peroxidation (LPO) in mitochondrial fractions. Results: Pretreatment with Z. armatum fruit at two different concentrations (200mg, 400mg/kg body weight) not only increased the activities of endogenous antioxidant enzymes (SOD, CAT, GPx, GST) and reduced glutathione (GSH) but also decreased the level of LPO in myocardial infarction (MI) induced rat heart mitochondria exposed to ISO. Conclusion: The enhanced antioxidant activity of Z. armatum fruit protected the heart mitochondria in rats against ISO-induced damage. This study may have a significant impact on the diseases that is caused by free radicals and the role of antioxidants in averting the diseases.