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1.
The effects of supplementation of beef cattle diets with organic Se (0.3 mg/kg) and vitamin E (300 I.U. alpha-tocopheryl acetate/kg feed), for 55 d preceding slaughter, on the antioxidant status and oxidative stability of muscle was examined. Dietary vitamin E supplementation led to an increase (P < 0.05) in plasma, and longissimus muscle alpha-tocopherol levels. In minced longissimus muscle stored in 80% 02:20% CO2, lipid and oxymyoglobin oxidation were lower (P < 0.05) in muscle from vitamin E-supplemented animals compared with unsupplemented animals. Dietary Se supplementation did not significantly affect muscle Se levels, glutathione peroxidase activity, or susceptibility to lipid and oxymyoglobin oxidation in the presence or absence of vitamin E. Covariance analysis indicated that, in addition to muscle alpha-tocopherol, differences in muscle glutathione peroxidase activity, and pH could account for variation in the susceptibility of muscle to lipid and oxymyoglobin oxidation.  相似文献   

2.
REASONS FOR PERFORMING STUDY: There is a lack of well documented studies about muscular lesions in equine atypical myopathy (EAM). OBJECTIVES: To characterise morphopathological changes of striated muscles and myocardium, to progress understanding of this disease. METHODS: Thirty-two horses age 0.5-7 years kept on pasture were referred for a sudden ataxia/myoglobinuria syndrome. Clinical examination (stiffness, muscle pain, muscle fasciculations, abnormal gait, recumbency, myoglobinuria, tachycardia, sweating) and plasma CPK, LDH and AST levels were consistent with extensive myonecrosis and, together with anamnestic data, with so-called 'equine atypical myopathy' (EAM), a disease of unknown aetiology reported since 1939. Macroscopic and microscopic (histology, histoenzymology, ultrastructure) lesions were evaluated. RESULTS: Necropsic examination revealed large areas of muscle necrosis, the extent and severity of which varied between cases and muscles, but which were clearly more constant and severe in respiratory and postural muscles and in the myocardium. Histology highlighted a multifocal and monophasic process compatible with Zenker degeneration/necrosis that mostly and segmentally affected type 1 fibres. Histochemical evaluation revealed a weak and disorganised pattern of NADH tetrazolium reductase staining, the absence of calcium salts precipitates and a dramatic accumulation of lipid droplets. Ultrastructural examination often revealed fibres of which the sole modifications were altered mitochondria and sarcoplasmic lipidosis. CONCLUSIONS: Taken together, the data suggest that a primary alteration of mitochondria should be considered, although secondary mitochondrial abnormalities have yet to be ruled out. POTENTIAL RELEVANCE: The morphological features gathered here reveal that EAM shares most of the characteristics of toxic myopathies.  相似文献   

3.
肉色是衡量肉品质的重要感官指标,直接影响消费者的购买意愿。植物多酚是天然的抗氧化剂,日粮添加植物多酚可通过影响肌红蛋白氧化还原状态、脂质氧化程度及肌纤维类型来改善肉色及其稳定性。为进一步明确日粮中添加植物多酚调控肉色的作用机制,本文对植物多酚介导肉色稳定性的信号途径进行了综述,以期为今后通过在日粮中补充植物多酚调控机体抗氧化能力、促进肌纤维类型转化进而改善肉色提供理论依据。  相似文献   

4.
OBJECTIVE: To perform respiratory chain enzymatic activity assays on canine skeletal muscle biopsy specimens and establish reference range values of skeletal muscle enzyme activities for dogs. SAMPLE POPULATION: Biopsy specimens from the vastus lateralis muscle were obtained from 24 dogs (8 sexually intact males and 14 sexually intact females) ranging from 15 months to 6 years of age. PROCEDURE: Mean values of citrate synthase, cytochrome-c oxidase, succinate dehydrogenase, succinate dehydrogenase-cytochrome-c reductase, nicotinamide adenine dinucleotide (NADH) dehydrogenase, and NADH dehydrogenase-cytochrome-c reductase activities were established by use of 6 standard spectrophotometric assays for respiratory chain enzyme analysis. RESULTS: Compared with published data for skeletal muscle enzyme activities in humans, skeletal muscle enzyme activities in dogs were 2- to 4-fold higher. Additionally, citrate synthase activity, a marker for mitochondrial volume, was positively correlated with age in dogs, suggesting that mitochondrial volume increases with age, although no apparent change in respiratory chain enzymatic activity with an increase in age was found. CONCLUSIONS AND CLINICAL RELEVANCE: Reference range values for skeletal muscle enzyme activities of dogs are needed to accurately interpret results of respiratory chain enzymatic activity assays. During investigation of metabolic myopathies, if skeletal muscle biopsy specimens are evaluated for respiratory chain enzyme kinetics, they should be performed and evaluated in concert with skeletal muscle biopsy specimens from clinically normal animals of the same species.  相似文献   

5.
Spermatozoa are vulnerable to oxidative attack because they contain an abundance of polyunsaturated fatty acids that are susceptible to lipid peroxidation. In addition, functionally important proteins and DNA are also subject to oxidative modification and adduction by aldehydes, such as 4-hydroxynonenal (4HNE), generated as a consequence of the peroxidative process. The proteins adducted by 4HNE include elements of the mitochondrial electron transport chain, such as succinic acid dehydrogenase. The net result of such electrophilic attack is to stimulate generation of mitochondrial reactive oxygen species (ROS) in a self-perpetuating lipid peroxidation–ROS generation cycle that ultimately triggers the intrinsic apoptotic pathway, leading to a rapid loss of motility and cell death. A major point of difference between apoptosis in spermatozoa and somatic cells is that in the former, nuclear DNA is located in a compartment (the head) separate from the mitochondria and most of the cytoplasm (the midpiece). As a result, nucleases activated and released in the midpiece during apoptosis cannot gain access to the DNA in the sperm head in order to cleave the DNA. However, the ROS generated during apoptosis can readily gain access to the sperm nucleus and generate oxidative base adducts, typically 8-hydroxy, 2′-deoxyguanosine (8OHdG), which are converted into abasic sites by 8-oxoguanine glycosylase (OGG1), the only enzyme of the base excision repair pathway possessed by spermatozoa. These abasic sites subsequently become the foci of DNA fragmentation. Because defective sperm function and DNA damage are frequently associated with oxidative stress, there is a great deal of interest in the use of antioxidants in a therapeutic context. This presentation examines the fundamental relationships between oxidative stress and sperm function and considers the implications of recent findings for the management of sperm function and fertility in stallions.  相似文献   

6.
This study investigates the effect of the addition of plant‐derived extracts (control, garlic extract or a combination of carvacrol, thymol, cinnamic aldehyde and eugenol oils extracts) to pig feedstuff and the reduction in salt content (NaCl or a mixture 60:40 sodium chloride:potassium lactate) on some physicochemical characteristics and consumer acceptability of dry‐fermented sausages. Six different batches were formulated. The pH, color, lipid oxidation, and microbial counts were measured, and a consumer home test was performed. Both the use of a plant‐derived extract and salt type affected the dry‐fermented sausage characteristics. The low‐salt batches presented a lower pH and higher microbial counts than the control. The salt reduction affected the color but only in the oil batches, resulting in higher L* and lower a* values. The oil batches presented the highest TBAR values (>1 mg/kg), suggesting that antioxidant compounds present into the meat were not bioavailable on the sausages or were missed during the curing process. The use of plant‐derived extracts affected to consumer acceptability, whereas salt replacement did not. Oil batches scored lower than the other. From the current results, the oil extract would not be a recommended additive in pig feedstuff, especially when a low‐salt strategy will be employed.  相似文献   

7.
Typical skeletal muscles are composed of mixed muscle fiber types, which are classified as slow-twitch (type I) and fast-twitch (type II) fibers, whereas pectoralis major muscles (PMs) in broiler chickens are 100% composed of type IIb fast-twitch fibers. Since metabolic properties differ among muscle fiber types, the combination of muscle fiber types is involved in physiological functions and pathological conditions in skeletal muscles. In this study, using serial block-face scanning electron microscopy, we compared three-dimensional (3D) mitochondrial properties in type IIb fibers in broiler PMs and those in type I fibers of broiler gastrocnemius muscles (GMs) heterogeneously composed of slow- and fast-twitch muscle fibers. In type I fibers in the GMs, elongated mitochondria with numerous interconnections to form a substantial network among myofibrils were observed. Along with lipid droplets sandwiched by mitochondria, these features are an adaptation to effective oxidative respiration and constant oxidative damage in slow-twitch muscle fibers. In contrast, type IIb fibers in the PMs showed small and ellipsoid-shaped mitochondria with few interconnections and no lipid droplets, forming a sparse network. The mitochondrial spatial network comprises of active mitochondrial dynamics to reduce mitochondrial damage; therefore, type IIb fibers possess physiologically low capacity to maintain mitochondrial wellness due to static mitochondrial dynamics. Based on 3D mitochondrial properties, we discussed the contrasting physiological functions between type I and IIb fibers and proposed a high contractile power and low stress resistance as unique physiological properties of broiler PMs.  相似文献   

8.
9.
Recent investigations were conducted on mitochondria obtained from broilers with low and high feed efficiency (FE) within the same genetic line that were fed the same diet, thereby allowing relationships between mitochondrial function and the phenotypic expression of FE to be clearly established. In these studies, breast muscle, liver and duodenal mitochondria obtained from broilers with high FE exhibited a more tightly coupled respiratory chain along with lower electron leak and reactive oxygen species (ROS) production compared with broilers with low FE. Elevated electron leak in low FE was due to site-specific defects in electron transport at Complex I, III, or both of the respiratory chains in breast and leg muscles and at Complex I, II, or III (depending on energy substrate) in duodenal mitochondria. Increased ROS production was presumably responsible for increased protein oxidation in low FE muscle mitochondria. Of 14 respiratory chain proteins investigated in breast muscle, the expression of 4 (3 in Complex III and 1 in Complex IV) was higher in low FE mitochondria. Interestingly, low FE was associated with a general suppression in respiratory chain complex activities (I, II, III, and IV) in breast muscle and liver. Elucidation of the mechanisms responsible for lower ROS production and tighter coupling of the respiratory chain in high FE mitochondria will greatly facilitate our understanding of the cellular basis for the phenotypic expression of FE.  相似文献   

10.
肌红蛋白影响畜禽活体肌肉和宰后鲜肉肉色的研究进展   总被引:4,自引:0,他引:4  
肉色是影响消费者购买肉产品的最主要因素,因为消费者通过肉色对肉产品新鲜度和卫生状况产生第一印象。肉色的化学本质是肌红蛋白分子,本文综述了4个肌红蛋白分子(脱氧肌红蛋白、氧合肌红蛋白、高铁肌红蛋白、碳氧肌红蛋白)的结构及其相互转化反应和对畜禽活体肌肉和宰后鲜肉肉色的影响。  相似文献   

11.
Studies have demonstrated the importance of mitochondria to sperm functionality, as the main source of ATP for cellular homoeostasis and motility. However, the role of mitochondria on sperm metabolism is still controversial. Studies indicate that, for some species, glycolysis may be the main mechanism for sperm energy production. For ram sperm, such pathway is not clear. Thus, we evaluated ram sperm in response to mitochondrial uncoupling and glycolysis inhibition aiming to assess the importance of each pathway for sperm functionality. Statistical analysis was performed by the SAS System for Windows, using the General Linear Model Procedure. Data were tested for residue normality and variance homogeneity. A p < .05 was considered significant. Groups treated with the mitochondrial uncoupler Carbonyl cyanide 3 chlorophenylhydrazone (CCCP) showed a decrease in the percentage of cells with low mitochondrial activity and high mitochondrial membrane potential. We also observed that the highest CCCP concentration promotes a decrease in sperm susceptibility to lipid peroxidation. Regardless the lack of effect of CCCP on total motility, this substance induced significant alterations on sperm kinetics. Besides the interference of CCCP on spermatic movement patterns, it was also possible to observe such an effect in samples treated with the inhibitor of glycolysis (2‐deoxy‐d ‐glucose, DOG). Furthermore, treatment with DOG also led to a dose‐dependent increase in sperm susceptibility to lipid peroxidation. Based on our results, we suggest that the glycolysis appears to be as important as oxidative phosphorylation for ovine sperm kinetics as this mechanism is capable of maintaining full motility when most of the cells have a low mitochondrial membrane potential. Furthermore, we found that changes in the glycolytic pathway trough glycolysis inhibition are likely involved in mitochondrial dysfunction and sperm oxidative unbalance.  相似文献   

12.
A trial was conducted to biochemically explain the decreased lipid deposition and increased protein accretion observed in pigs fed carnitine. Our hypothesis was that an increase in the ratio of acetyl CoA:CoA-SH produced by stimulation of fatty acid oxidation by supplemental L-carnitine may decrease branched-chain alpha-keto acid dehydrogenase activity and increase pyruvate carboxylase activity. Such changes could reduce oxidative loss of branched-chain amino acids and provide more carbons for amino acid biosynthesis. Yorkshire gilts (n = 36; 12 per treatment) were fed a control diet or diets containing either 50 or 125 ppm of added L-carnitine during growth from 56 to 120 kg. After slaughter, the semitendinosus muscle and liver were collected for isolation of mitochondria and hepatocytes. Increasing dietary L-carnitine did not influence growth performance (P > 0.10) but linearly decreased (P < 0.05) 10th rib backfat thickness and increased (linear, P < 0.05) percentages of lean and muscle. The rates of [1-(14)G]palmitate oxidation in isolated hepatocytes and isolated mitochondria, and incorporation of [35S]methionine into the acid insoluble fraction of isolated hepatocytes were increased (linear, P < 0.01) in pigs fed L-carnitine. Flux through branched-chain alpha-keto acid dehydrogenase linearly decreased (P < 0.01) in isolated liver and muscle mitochondria with increasing dietary carnitine. Flux through pyruvate carboxylase was increased (linear, P < 0.01) in isolated mitochondria from liver of pigs fed carnitine, and assays with particle-free extracts indicated that the amount of mitochondrial pyruvate carboxylase was tripled by feeding carnitine (linear, P < 0.01). The association of increased protein accretion and reduced backfat thickness with greater rates of palmitate oxidation, more rapid flux through pyruvate carboxylase, and reduced flux through branched-chain alpha-keto acid dehydrogenase suggests pigs fed carnitine are more able to use fat for energy, divert carbon toward synthesis of amino acids, and spare branched-chain amino acids for protein synthesis.  相似文献   

13.
This study evaluated the effects of cryopreservation by slow freezing on the mitochondrial function, DNA integrity, and developmental ability of bovine embryos and examined whether resveratrol treatment of the frozen‐thawed blastocysts improved embryonic viability. In vitro produced bovine embryos were subjected to slow freezing. After thawing, the ATP content and mitochondrial DNA integrity (mtDNA), determined by real‐time PCR targeting short and long mitochondrial sequences, was found to be lower in frozen‐thawed embryos than in fresh embryos, and mtDNA copy number was significantly reduced during the 24‐hr incubation post warming. Furthermore, immunostaining against double‐strand DNA revealed DNA damage in frozen‐thawed embryos. When frozen‐thawed embryos were incubated in the medium containing 0.5 µM resveratrol, SIRT1 expression, and survival rate of the embryos significantly improved compared with the vehicle‐treated embryos. In addition, cell‐free mtDNA content in medium was higher in case of resveratrol‐treated embryos than of vehicle‐treated embryos. In conclusion, slow freezing affects mitochondrial integrity and function in the blastocysts. In the frozen‐thawed embryos, mitochondria were removed during post‐thawing incubation and resveratrol enhanced the process, resulting in improved survivability of the embryos.  相似文献   

14.
Cytopathic bovine viral diarrhoea viruses (cp BVDV) induce apoptosis in permissible cell cultures via the intrinsic pathway, which involves the mitochondria as key organelles. An important event is the irreversible opening of the permeability transition pore (PTP) and the breakdown of the transmembrane potential DeltaPsi(m). The resulting release of cytochrome C from the mitochondria serves as a trigger to form the apoptosome which then leads to caspase activation and cell death. In contrast, noncytopathic (ncp) BVDV do not seem to affect cells in vivo or in vitro, suggesting that they inhibit apoptosis. Interestingly, inhibition of caspases in cells infected with cp BVDV delayed the apoptotic cascade but did not prevent the cytopathic effect (CPE). This suggests that the induction of apoptosis and the processes finally leading to the CPE may proceed separately, implying that the inhibition of apoptosis by ncp BVDV has to start earlier in the cascade. In this study we show that in fact apoptosis inhibition in cells infected with ncp BVDV must occur at the mitochondrial level, before the activation of the caspase cascade occurs. To elucidate the role of mitochondria after infection of cells with ncp BVDV, expression of Bcl-2 and Bax were analysed. It was shown that while Bax expression was not affected, the anti-apoptotic Bcl-2 protein was upregulated, presumably suppressing initiation of cell death and enabling persistent infection in vitro.  相似文献   

15.
Oxidative stress is a major factor explaining sperm dysfunction of spermatozoa surviving freezing and thawing and is also considered a major inducer of a special form of apoptosis, visible after thawing, in cryopreserved spermatozoa. To obtain further insights into the link between oxidative stress and the induction of apoptotic changes, stallion spermatozoa were induced to oxidative stress through redox cycling after exposure to 2‐methyl‐1,4‐naphthoquinone (menadione), or hydroxyl radical formation after FeSO4 exposure. Either exposure induced significant increases (p < 0.05) in two markers of lipid peroxidation: 8‐iso‐PGF and 4‐hydroxynonenal (4‐HNE). While both treatments induced changes indicative of spermptosis (caspase‐3 activation and decreased mitochondrial membrane potential) (p < 0.01), menadione induced sperm necrosis and a dramatic reduction in motility and thiol content in stallion spermatozoa. Thus, we provided evidence that oxidative stress underlies spermptosis, and thiol content is a key factor for stallion sperm function.  相似文献   

16.
Oleic acid (18:1n‐9) is the most abundant fatty acid in bovine adipose tissue. Because most of the lipid in bovine muscle is contributed by intramuscular adipocytes, oleic acid also is the predominant fatty acid in beef. In many species, the concentration of oleic acid in adipose tissue is dictated by the average concentration of oleic acid in the diet, but in ruminant species such as beef cattle, oleic acid is hydrogenated largely to stearic acid by ruminal microorganisms. In these species, the concentration of oleic acid in adipose tissue is dependent upon the activity of Δ9 desaturase, encoded by the stearoyl coenzyme A desaturase (SCD) gene. Expression of the SCD gene is essential for bovine preadipocyte differentiation, and desaturase gene expression and catalytic activity increase dramatically as adipose tissue mass increases after weaning. Feeding a hay‐based diet to American Wagyu steers to a typical Japanese bodyweight endpoint (650 kg) markedly stimulated desaturase enzyme activity as well as the accumulation of both oleic acid and intramuscular lipid, but the increase in oleic acid and intramuscular lipid was much less in hay‐fed Angus steers. Increasing the concentration of oleic acid improves the palatability and healthiness of beef, and Korean Hanwoo and Japanese Black (and American Wagyu) seem especially well adapted to accumulate oleic acid in their adipose tissue.  相似文献   

17.
选用1日龄健康AA肉鸡120只随机均分成4组,使用硫酸铜作为铜源,饲喂玉米-豆粕型基础日粮,对照组饲料铜含量为11mg/kg,3个试验高铜组饲料铜含量分别为110,220,330mg/kg,试验至60日龄结束,来探讨高铜日粮对肉鸡肝线粒体膜通透性、脂类代谢及肝和肌肉铜含量的影响。结果显示:(1)随着铜浓度的增加和/或饲养日龄的延长,线粒体膜通透性转换孔(Mitochondrial permeability transition pore,MPTP)逐渐扩大(P0.05);(2)血清总胆固醇(T-Ch)含量110,220mg/kg铜添加组低于对照组(P0.05),330mg/kg铜添加组极显著低于对照组(P0.01),而甘油三酯(TG)的含量在各高铜组均极显著低于对照组(P0.01);(3)与对照组相比,肝脏铜含量110,220mg/kg铜添加组有所增加(P0.05),330mg/kg铜添加组极显著增加(P0.01),肌肉中铜含量在各高铜组均极显著高于对照组(P0.01)。这说明高铜可造成肝线粒体不同程度的肿胀和损伤,改变肉鸡脂类的新陈代谢,明显增加肝和肌肉组织的铜含量。  相似文献   

18.
以45 ℃老化48 d的超干燕麦种子(含水量4%)为材料,通过水势为0(蒸馏水)和-1.2 MPa的 PEG-6000在20 ℃黑暗条件引发12 h后,分析其发芽率、发芽指数、平均发芽时间及幼苗活力指数,种胚细胞及线粒体的超微结构、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)和丙二醛(MDA)含量的变化,以探讨PEG引发对其萌发及幼苗生长、种胚细胞及线粒体结构和抗氧化性能的影响。结果表明:PEG引发提高了超干燕麦老化种胚细胞及其线粒体的SOD、APX及GR活性,其种胚细胞内SOD、APX和GR活性分别提高了26.7%、20.9%和26.9%,其线粒体内SOD、APX和GR活性分别提高了19.2%、19.4%和17.1%,使种胚细胞及线粒体内MDA含量分别降低了28.3%和13.7%,并维持了其正常的细胞及线粒体结构,从而促进其萌发。然而,蒸馏水引发则相反。种胚细胞与线粒体在超干燕麦老化种子的引发过程中具有协同性,且线粒体发挥着更重要的作用。  相似文献   

19.
In mammals, excess energy is stored primarily as triglycerides, which are mobilized when energy demands arise and cannot be covered by feed intake. This review mainly focuses on the role of long chain fatty acids in disturbed energy metabolism of the bovine species. Long chain fatty acids regulate energy metabolism as ligands of peroxisome proliferator-activated receptors. Carnitine acts as a carrier of fatty acyl groups as long-chain acyl-CoA derivatives do not penetrate the mitochondrial inner membrane. There are two different types of disorders in lipid metabolism which can occur in cattle, namely the hypoglycaemic-hypoinsulinaemic and the hyperglycaemic-hyperinsulinaemic type with the latter not always associated with ketosis. There is general agreement that fatty acid β-oxidation capability is limited in the liver of (ketotic) cows. In accord, supplemental L-carnitine decreased liver lipid accumulation in periparturient Holstein cows. Of note, around parturition concurrent oxidation of fatty acids in skeletal muscle is highly activated. Also peroxisomal β-oxidation in liver of dairy cows may be part of the hepatic adaptations to a negative energy balance (NEB) to break down fatty acids. An elevated blood concentration of nonesterified fatty acids is one of the indicators of NEB in cattle among others like increased β-hydroxy butyrate concentration, and decreased concentrations of glucose, insulin, and insulin-like growth factor-I. Assuming that liver carnitine concentrations might limit hepatic fatty acid oxidation capacity in dairy cows, further study of the role of acyl-CoA dehydrogenases and/or riboflavin in bovine ketosis is warranted.  相似文献   

20.
The study was conducted to investigate the effects of dietary leucine on antioxidant activity and expression of antioxidant‐ and mitochondrial‐related genes in longissimus dorsi muscle and liver of piglets. Three diets were formulated with different levels of supplemented leucine (0%, 0.25%, 0.5%). Results showed that supplementation of 0.25% leucine significantly increased antisuperoxide anion (ASA) and antihydroxyl radical (AHR) levels and activities of total superoxide dismutade (T‐SOD), glutathione peroxidase (GPx), glutathione S‐transferase (GST), and total antioxidant capacity (T‐AOC) in serum, longissimus dorsi muscle and liver of piglets as compared with the control group. The SOD2, catalase (CAT), GPx, GST, glutathione reductase (GR), and nuclear factor erythroid 2‐related factor 2 (Nrf2) mRNA levels in longissimus dorsi muscle and liver were significantly increased by 0.25% leucine supplementation. However, the malondialdehyde (MDA) content and the mRNA level of Kelch‐like ECH‐associated protein 1 (Keap1) exhibited an opposite tendency. Additionally, supplementation of 0.25% leucine significantly increased the mRNA levels of mitochondrial‐related genes in longissimus dorsi muscle and liver of piglets. Results suggested that supplementation of 0.25% leucine improved antioxidant activity and mitochondrial biogenesis and function of piglets, which was related to the increase in antioxidant enzymes activities and upregulation of expression of antioxidant‐ and mitochondrial‐related genes.  相似文献   

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