We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis. Moisture, protein, lipid and ash contents were determined by methods of Association of Analytical Chemist (AOAC) International. Fatty acid profile was determined by gas chromatography. Crude protein, fat, moisture and ash contents showed no significant differences between the two age groups. The contents of total polyunsaturated fatty acids and docosahexaenoic acid (DHA) were significantly higher and eicosapentaenoic acid (EPA) content was significantly lower in the two-year-old large yellow croaker than in the one-year-old (P<0.05). No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty acids, or the ratio of n-3/n-6 fatty acids among the large yellow croakers of the two age groups. We conclude that large yellow croakers are good food sources of EPA and DHA.
Age Factors ; Animals ; Fatty Acids ; analysis ; Muscles ; chemistry ; Perciformes ; metabolism

In order to elucidate mechanisms of Ca++ antagonistic action of kanamycin in the biological system, the effects of kanamycin on Ca++ transport in sarcoplasmic reticulum of rabbit skeletal muscle and liver mitochondria were studied. At the same time, the effect of the agent on Bowditch and Woodworth phenomena of rabbit heart as well as the superprecipitation of actomyosin isolated from rabbit skeletal muscle were studied. Since kanamycin inhibits the Bowditch staircase phenomena in rabbit cardiac muscle, it is speculated that kanamycin inhibits Ca++ influx across the cell membrane which is required for the muscular contraction. Kanamycin also inhibits the Woodworth staircase phenomena, indicating a decrease in size of the Ca++ pool in cardiac muscle which may be brought about by an inhibition of Ca++ transport in sarcoplasmic reticulum and mitochondria. Actually, kanamycin was found to inhibit both the activities of Ca++ activated adenosine triphosphatases (ATPase) and Ca++ transport in sarcoplasmic reticulum and mitochondria. Kanamycin also inhibits both the development of superprecipitation and the activity of Ca++activated ATPase of skeletal actomyosin in rabbits. From the results obtained above, it may be concluded that kanamycin possesses a Ca++ antagonistic action in the biological system.
Animal ; Calcium/antagonists & inhibitors* ; Kanamycin/pharmacology* ; Mitochondria, Liver/metabolism ; Muscles/metabolism ; Myocardium/metabolism ; Rabbits

Extracellular ATP (exATP) has been known to be a critical ligand regulating skeletal muscle differentiation and contractibility. ExATP synthesis was greatly increased with the high level of adenylate kinase 1 (AK1) and ATP synthase beta during C2C12 myogenesis. The exATP synthesis was abolished by the knock-down of AK1 but not by that of ATP synthase beta in C2C12 myotubes, suggesting that AK1 is required for exATP synthesis in myotubes. However, membrane-bound AK1beta was not involved in exATP synthesis because its expression level was decreased during myogenesis in spite of its localization in the lipid rafts that contain various kinds of receptors and mediate cell signal transduction, cell migration, and differentiation. Interestingly, cytoplasmic AK1 was secreted from C2C12 myotubes but not from C2C12 myoblasts. Taken together all these data, we can conclude that AK1 secretion is required for the exATP generation in myotubes.
Adenosine Triphosphate/*biosynthesis ; Adenylate Kinase/*metabolism ; Animals ; Cell Line ; Extracellular Space/metabolism ; Isoenzymes/*metabolism ; Mice ; Muscles/cytology/*metabolism

The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (control and fasted) and reared in 6 cages. After two weeks of adaptation, group I fasted for 28 d; group II was fed normally as a control. In 3, 7, 14, 21 and 28 d, 6 fish per group were sampled for proximate flesh composition, liver antioxidant enzyme activities and malondialdehyde flesh content analyses. In fasted fish, the reduction of lipid content in muscle occurred after day 3, and, compared to controls, the content of protein decreased from day 14, the activities of liver antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) increased from day 3, and flesh malondialdehyde levels increased from day 21. Flesh fat reduction shows that fasting may be used as a technique to reduce flesh lipid content in Sparus macrocephalus. However, considering flesh protein loss and the subsequent oxidative stress, the fasting technique should be used with precautions.
Animal Feed ; Animals ; Antioxidants ; metabolism ; Fasting ; physiology ; Glutathione Peroxidase ; metabolism ; Liver ; enzymology ; Malondialdehyde ; metabolism ; Muscles ; metabolism ; Perciformes ; metabolism ; Superoxide Dismutase ; metabolism

Aging affects metabolism, leading to physiological and functional impairments, and is also related to changes in body composition, including reduced skeletal muscle mass and increased body fat. These changes are correlated with the pathophysiology of sarcopenia, which is defined as age-related loss of skeletal muscle mass and strength. Low testosterone levels are associated with unfavorable body composition changes, and sex hormones decrease with aging. Androgen deficiency, along with lack of exercise and poor nutrition, may be among the modifiable contributors to sarcopenia. Testosterone treatment has been reported to have beneficial effects on muscle mass and function, but the results have been inconsistent. Here, we discuss the correlation between testosterone and muscle mass and function, the impact of testosterone on sarcopenia, and the probable mechanisms underlying these effects.
Adipose Tissue ; Aging ; Body Composition ; Gonadal Steroid Hormones ; Metabolism ; Muscle, Skeletal ; Muscles ; Sarcopenia* ; Testosterone*

A case of Leigh's disease (subacute necrotizing encephalomyelopathy) is reported with such noteworthy features as early onset, dystonia, paraparesis the presence of low attenuation areas in both basal ganglias on computerized tomography of the brain and the presence of a high signal intensity in both basal ganglias in T2 weighted image by MR. The electron microscopic findings of muscle biopsy are suggestive of pleoconial mitochondrial myopathy.
Basal Ganglia/pathology ; Case Report ; Dystonia/diagnosis/*etiology ; Energy Metabolism ; Human ; Infant ; Leigh Disease/*diagnosis/metabolism/pathology ; Male ; Muscles/pathology

OBJECTIVETo study apoptosis and expression of apoptosis-related proteins in experimental different denervated guinea-pig facial muscle.

METHODAn experimental model was established with guinea pigs by compressing the facial nerve 30 second (reinnervated group) and resecting the facial nerve (denervated group). TUNEL method and immunohistochemical technique (SABC) were applied to detect the apoptosis and expression of apoptosis-related proteins bcl-2 and bax from 1st to 8th week after operation.

RESULTExperimentally denervated facial muscle revealed consistently increase of DNA fragmentation, average from(34.4 +/- 4.6)% to (38.2 +/- 10.6)%, from 1st week to 8th week after operation; Reinnervated facial muscle showed a temporal increase of DNA fragmentation, and then the muscle fiber nuclei revealed decreased DNA fragmentation along with the function of facial nerve recovered, latterly normal, average from (32.0 +/- 8.03)% to (5.6 +/- 3.5)%, from 1st week to 8th week after operation. In denervated group, bcl-2 and bax were expressed strongly; in reinnervated group, bcl-2 expressed consistently, but bax disappeared latterly along with the function of facial nerve recovered.

CONCLUSIONExpression of DNA fragmentation and apoptosis-related proteins in denervated muscle are general reaction to denervation. bcl-2 can prevent early apoptotic muscle fiber to survival until reinnervation. It is concluded that proteins control apoptosis may give information for possible therapeutic interventions to reduce the rate of muscle fiber death in denervated atrophy in absence of effective primary treatment.

Animals ; Apoptosis ; Denervation ; Facial Muscles ; cytology ; innervation ; metabolism ; Female ; Guinea Pigs ; Male ; Proto-Oncogene Proteins c-bcl-2 ; metabolism

OBJECTIVE: To investigate the expression of myosin heavy chain (MHC) in normal laryngeal muscle and the difference between the adductor and abductor. METHOD: Seven patients with total laryngectomy were enrolled in this study. The adductor muscles were acquired from the lateral cricoarytenoid (LCA) muscle and the abductor muscles were acquired from the posterior cricoarytenoid (PCA) muscle. The expression of myosin heavy chain were detected with fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining respectively. RESULT: (1) MHC-II b was expressed in laryngeal muscles at mRNA levels, and not expressed at the protein level; (2) At both mRNA level and protein level, the expression of MHC-I was higher in the PCA muscles than in the LCA muscles while MHC-II level was higher in the LCA muscles than in the PCA muscles. CONCLUSION (1) MHC-II b protein was not expressed in human laryngeal muscles; (2) Phenotypic differences were significant in laryngeal adductor and abductor muscles based on their different functions. PCA contained larger percentage of MHC-I fibers, while LCA contained more MHC-II fibers.
Aged ; Female ; Humans ; Laryngeal Muscles ; chemistry ; metabolism ; Male ; Middle Aged ; Myosin Heavy Chains ; genetics ; metabolism ; Phenotype ; Protein Isoforms

OBJECTIVETo investigate the activity of bilateral posterior cricoarytenoid muscle satellite cell after denervation or reinnervation with ansa cervicalis.

METHODSTwenty four dogs were randomly divided into 3 groups. The bilateral laryngeal recurrent nerves were cut in group one in all dogs. The bilateral laryngeal recurrent nerves were anastomosed with ansa cervicalis after incision in group two in all dogs. The dogs in group three were used as control. Nine weeks after surgery, the electromyography was used to test the regeneration of the nerve. The posterior cricoarytenoid muscles biopsy were collected. The expression of mRNA of Myogenin, Myf5, and Pax7 was assayed by realtime RT-PCR after total RNA isolation.

RESULTSTwo dogs died after surgery in incision and anastomose group. The electromyography suggested that the RLN of all dogs had denervated in the incision group and had reinnervated in the anastomose group after 9 weeks. Myogenin mRNA from RLN incision dogs PCA muscles had greater expression versus controls (Z = 1.42, P < 0.01) or anastomosed dogs (Z = 1.38, P < 0.01). Myf5 mRNA expression from RLN incision dogs PCA muscles had significant increase versus control dogs (Z = 1.66, P < 0.01) or anastomosed dogs (Z = 1.69, P < 0.01). Pax7 mRNA expression from RNL incision dogs had significant increase compared with control (Z = 1.66, P < 0.01) or anastomosed animals (Z = 1.42, P < 0.05). There was no significant difference in Myogenin (Z = 1.34, P > 0.05), Myf5 (Z = 0.54, P > 0.05) and Pax (Z = 0.54, P > 0.05) mRNA expression between controls and anastomosed animals.

CONCLUSIONSThe bilateral denervation of RLN cause significantly increasing in dog PCA muscle satellite cell proliferation and differentiation. The bilateral reinnervation of RLN cause PCA muscle satellite cell come back nonproliferative, quiescent state in dog.

Animals ; Cell Differentiation ; Cell Proliferation ; Dogs ; Laryngeal Muscles ; innervation ; Muscle Denervation ; Neck Muscles ; innervation ; Recurrent Laryngeal Nerve ; surgery ; Satellite Cells, Perineuronal ; cytology ; metabolism

We investigated the effects of simulated ischemia on intracellular Cl- concentration ([Cl-]i) in guinea pig ventricular myocardial cells and possible role of the [Cl-]i on the ischemia/reperfusion-induced arrhythmias in perfused rat hearts. Our results provided direct evidence that the [Cl-]i in ventricular muscle was increased under ischemic conditions, which suggested that activation of the Cl-(-)HCO3- exchanger by ischemia would partially contribute to the elevation of [Cl-]i. Application of stilbene derivatives or lowering Cl- concentration in perfusion solution delayed the onset of ischemia-induced deterioration in action potentials, pHi, [Cl-]i, and suppressed the incidence of ischemia/reperfusion-induced arrhythmias. The conclusion was made to emphasize the important role of intracellular Cl- homeostasis in cardiac physiology and pathogenesis of myocardial ischemia/reperfusion injury.
Action Potentials ; Animals ; Arrhythmias, Cardiac ; etiology ; metabolism ; Chlorides ; metabolism ; Guinea Pigs ; Hydrogen-Ion Concentration ; Microelectrodes ; Myocardial Reperfusion Injury ; complications ; metabolism ; Myocytes, Cardiac ; metabolism ; Papillary Muscles ; cytology