Quantitative proteomics is a technique that allows for large-scale comparison of the levels of individual proteins present in a biological sample. This technique has not previously been applied to examine the response of skeletal muscle proteins to an acute bout of exercise. In the present study, quantitative proteomics was applied to investigate whether the levels of individual skeletal muscle proteins are acutely affected by a short bout of high-intensity exercise. Gastrocnemius muscle was sampled from fasted rats either at rest, immediately following 3 min of high-intensity exercise or after 30 min of recovery. Muscle samples were submitted to two-dimensional gel electrophoresis and 61 of the resulting protein spots were selected for quantitative analysis. It was found that skeletal muscle protein levels were generally not acutely affected by a short bout of high-intensity exercise, with only four of the 61 proteins selected for analysis being significantly altered. These altered proteins were identified using liquid chromatography electrospray ionization-tandem mass spectrometry as creatine kinase, troponin T and a combination of heat shock 20 kDa protein and adenylate kinase 1. In conclusion, quantitative proteomics is sensitive enough to detect acute changes in skeletal muscle protein levels in response to exercise. We have found that the levels of most individual skeletal muscle proteins are not immediately altered in response to a short bout of high-intensity exercise and recovery in fasted rats.

summaryBreast volume and morphology of eight subjects were measured before conception and at intervals throughout pregnancy until 1 month of lactation. Breast volume before conception ranged from 293 to 964 ml. At the end of pregnancy the volume of breast tissue had increased by 145 ± 19 ml (mean ± s.e.m., n = 13 breasts, range 12-227 ml) with a further increase to 211 ± 16 ml (n = 12 breasts, range 129-320 ml) by 1 month of lactation. Urinary excretion of lactose increased at 22 weeks of pregnancy, signalling the capacity of the breast to synthesize lactose at this time. During pregnancy, both the change in breast volume and the change in cross-sectional area of the areola were related to the concentration of human placental lactogen in the plasma. The growth of the nipple and the rate of excretion of lactose were related to the concentration of prolactin in the plasma. During the first 3 days after birth, the rate of excretion of lactose was related to the rate of excretion of progesterone. There was no relationship between the growth of the breast during pregnancy and the amount of milk produced at 1 month of lactation.

-Our results suggest that isolated cardiomyocytes are capable of downregulating energy-consuming processes other than contraction when oxygen supply is decreased. Regions of myocardial tissue are also capable of downregulating metabolic activity during ischemia by shutting down contractile activity (myocardial hibernation). We suggest that metabolic downregulation associated with myocardial hibernation may not be exclusively due to reduced rates of contractile activity. Other energy-using processes (eg, protein synthesis, mRNA synthesis, ion channel activity, and proton leak) may also be shut down.

Background: Stagonospora nodorum, a fungal ascomycete in the class dothideomycetes, is a damaging pathogen of wheat. It is a model for necrotrophic fungi that cause necrotic symptoms via the interaction of multiple effector proteins with cultivar-specific receptors. A draft genome sequence and annotation was published in 2007. A second-pass gene prediction using a training set of 795 fully EST-supported genes predicted a total of 10762 version 2 nuclear-encoded genes, with an additional 5354 less reliable version 1 genes also retained.

Oxidative stress and alterations in cellular calcium homeostasis are associated with the development of cardiac hypertrophy. However, the early cellular mechanisms for the development of hypertrophy are not well understood. Guinea pig ventricular myocytes were exposed to 30 microM H(2)O(2) for 5 min followed by 10 units/mL catalase to degrade the H(2)O(2), and effects on protein expression were examined 48 h later. Transient exposure to H(2)O(2) increased the level of protein synthesis more than 2-fold, assessed as incorporation of [(3)H]leucine (n = 12; p < 0.05). Cell size was increased slightly, but there was no evidence of major cytoskeletal disorganization assessed using fluorescence microscopy. Changes in the expression of individual proteins were assessed using iTRAQ protein labeling followed by mass spectrometry analysis (LC-MALDI-MSMS); 669 proteins were identified, and transient exposure of myocytes to H(2)O(2) altered expression of 35 proteins that were predominantly mitochondrial in origin, including TCA cycle enzymes and oxidative phosphorylation proteins. Consistent with changes in the expression of mitochondrial proteins, transient exposure of myocytes to H(2)O(2) increased the magnitude of the mitochondrial NADH signal 10.5 +/- 2.3% compared to cells exposed to 0 microM H(2)O(2) for 5 min followed by 10 units/mL catalase (n = 8; p < 0.05). In addition, metabolic activity was significantly increased in the myocytes 48 h after transient exposure to H(2)O(2), assessed as formation of formazan from tetrazolium salt. We conclude that a 5 min exposure of ventricular myocytes to 30 microM H(2)O(2) is sufficient to significantly alter protein expression, consistent with the development of hypertrophy in the myocytes. Changes in mitochondrial protein expression and function appear to be early sequelae in the development of hypertrophy.