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41.
Norepinephrine response to exercise at the same relative intensity before and after endurance exercise training 总被引:1,自引:0,他引:1
Greiwe Jeffrey S.; Hickner Robert C.; Shah Suresh D.; Cryer Philip E.; Holloszy John O. 《Journal of applied physiology》1999,86(2):531-535
It is welldocumented that endurance exercise training results in a bluntednorepinephrine (NE) response to exercise of a given absolute exerciseintensity. However, it is not clear what effect traininghas on the catecholamine response to exercise of the same relativeintensity because previous studies have provided conflicting results.The purpose of the present study was, therefore, to determine thecatecholamine response to exercise of the same relative exerciseintensity before and after endurance exercise training. Six women andthree men [age 28 ± 8 (SD) yr] performed 10 wk oftraining. Maximal O2 uptake(O2 max) wasdetermined during treadmill exercise. Fifteen-minute treadmill exercisebouts were performed at 60, 65, 70, 75, 80, and 85% ofO2 max before andafter training.O2 max was increasedby 20% (from 39.2 ± 7.7 to 46.9 ± 8.1 ml · kg1 · min1;P < 0.05) in response to training.Plasma NE concentrations were higher(P < 0.05) during exercise at thesame relative intensity after, compared with before, training at65-85% ofO2 max.Differences between heart rates and plasma epinephrine concentrationsafter, compared with before, training were not statisticallysignificant. These results provide evidence that the NE response toexercise is dependent on the absolute as well as the relative intensity of the exercise. 相似文献
42.
Muscle glycogen accumulation after endurance exercise in trained and untrained individuals 总被引:3,自引:0,他引:3
Hickner R. C.; Fisher J. S.; Hansen P. A.; Racette S. B.; Mier C. M.; Turner M. J.; Holloszy J. O. 《Journal of applied physiology》1997,83(3):897-903
Hickner, R. C., J. S. Fisher, P. A. Hansen, S. B. Racette,C. M. Mier, M. J. Turner, and J. O. Holloszy. Muscle glycogen accumulation after endurance exercise in trained and untrained individuals. J. Appl. Physiol. 83(3):897-903, 1997.Muscle glycogen accumulation was determined in sixtrained cyclists (Trn) and six untrained subjects (UT) at 6 and either48 or 72 h after 2 h of cycling exercise at ~75% peakO2 uptake(O2 peak), which terminated with five 1-min sprints. Subjects ate 10 gcarbohydrate · kg1 · day1for 48-72 h postexercise. Muscle glycogen accumulation averaged 71 ± 9 (SE) mmol/kg (Trn) and 31 ± 9 mmol/kg (UT) during the first 6 h postexercise (P < 0.01) and 79 ± 22 mmol/kg (Trn) and 60 ± 9 mmol/kg (UT) between 6 and 48 or 72 h postexercise (not significant). Muscle glycogenconcentration was 164 ± 21 mmol/kg (Trn) and 99 ± 16 mmol/kg(UT) 48-72 h postexercise (P < 0.05). Muscle GLUT-4 content immediately postexercise was threefoldhigher in Trn than in UT (P < 0.05)and correlated with glycogen accumulation rates (r = 0.66, P < 0.05). Glycogen synthase in theactive I form was 2.5 ± 0.5, 3.3 ± 0.5, and 1.0 ± 0.3 µmol · g1 · min1in Trn at 0, 6, and 48 or 72 h postexercise, respectively;corresponding values were 1.2 ± 0.3, 2.7 ± 0.5, and 1.6 ± 0.3 µmol · g1 · min1in UT (P < 0.05 at 0 h). Plasmainsulin and plasma C-peptide area under the curve were lower in Trnthan in UT over the first 6 h postexercise(P < 0.05). Plasma creatine kinaseconcentrations were 125 ± 25 IU/l (Trn) and 91 ± 9 IU/l (UT)preexercise and 112 ± 14 IU/l (Trn) and 144 ± 22 IU/l(UT; P < 0.05 vs.preexercise) at 48-72 h postexercise (normal: 30-200 IU/l).We conclude that endurance exercise training results in an increasedability to accumulate muscle glycogen after exercise. 相似文献
43.
The estimation of the amount of evolutionary divergence that has taken
place between two DNA coding sequences depends strongly on the degree of
constraint on amino acid replacements. If amino acid replacements are
relatively unconstrained, the individual nucleotide is the appropriate unit
of analysis and the method of Tajima and Nei can be used. If amino acid
replacements are constrained, however, this method is shown to be
inapplicable. For sequences with strong amino acid constraints, a method is
outlined analogous to the Tajima and Nei method using codons as the unit of
analysis. Only synonymous substitutions are used. Codon usage data can be
employed to estimate the necessary parameters of the calculation, or a
priori models of substitution may be employed. Sequences with significant
but intermediate constraints on amino acid replacements are, in principle,
unanalyzable.
相似文献
44.
Mitogenic activity of pituitary hormones on cell cultures of normal and carcinogen-induced tumor epithelium from rat mammary glands 总被引:5,自引:2,他引:3 下载免费PDF全文
Cell suspension containing normal or tumor epithelium were readily obtained by enzymatically digesting rat mammary glands from perphenazine-treated (prolactin-hypersecreting) cycling, female virgin animals or hormone- responsive mammary tumors from animal treated with dimethylbenzanthracene. Cell suspensions were fractioned into predominantly epithelial and predominantly stromal cells by their differential rates of attachment to culture dishes. Both normal mammary and tumor epithelial cells were characterized by the presence of specific cell-junctional complexes, desmosome-like structures, surface microvilli, and their ability to synthesize casein. Serum-dependent protease activity was greater in cultures derived from tumors, and cells from such cultures grew in agarose whereas those from the non-neoplastic gland did not. The addition of prolactin to the culture medium stimulated DNA synthesis in primary or secondary epithelial cultures from tumors, whereas additional insulin and hydrocortisone with prolactin were required for similar levels of DNA synthesis in cultures from non-neoplastic glands. The fraction of cells synthesizing DNA was, however, smaller than that with 10 percent serum measured in the same time period. Both growth hormone and epidermal growth factor stimulated DNA synthesis but to a lesser extent than did prolactin. Prolactin with hydrocortisone and insulin were relatively inactive in promoting DNA synthesis of the nonepithelial cells whereas pituitary fibroblast growth factor was more active. These mitogenic effects were obtained when the hormones were added to the medium at near physiological concentrations, and paralleled the known activities of the hormones in control of mammary gland growth and development in the rat. 相似文献
45.
Gordon SE Westerkamp CM Savage KJ Hickner RC George SC Fick CA McCormick KM 《Canadian journal of physiology and pharmacology》2007,85(6):646-651
The purpose of this study was to examine the effect of blocking nitric oxide synthase (NOS) activity via NG-nitro-L-arginine methyl ester (L-NAME) on myonuclear addition in skeletal muscle under basal and overloaded conditions. Female Sprague-Dawley rats (approx. 220 g) were placed into 1 of the following 4 groups (n = 7-9/group): 7-day skeletal muscle overload (O), sham operation (S), skeletal muscle overload with L-NAME treatment (OLN), and sham operation with L-NAME treatment (SLN). Plantaris muscles were overloaded via bilateral surgical ablation of the gastrocnemius muscles and L-NAME (0.75 mg/mL) was administered in the animals' daily drinking water starting 2 days prior to surgery and continued until sacrifice. Myonuclear addition was assessed as subsarcolemmal incorporation of nuclei labeled with 5-bromo-2'-deoxyuridine (approx. 25 mg.(kg body mass)-1.day-1) delivered via osmotic pump during the overload period. As expected, muscle wet mass, total protein content, fiber cross-sectional area, and myonuclear addition were significantly higher (p 相似文献
46.
A Pseudomonas aeruginosa TIR effector mediates immune evasion by targeting UBAP1 and TLR adaptors 下载免费PDF全文
Paul RC Imbert Arthur Louche Jean‐Baptiste Luizet Teddy Grandjean Sarah Bigot Thomas E Wood Stéphanie Gagné Amandine Blanco Lydia Wunderley Laurent Terradot Philip Woodman Steve Garvis Alain Filloux Benoit Guery Suzana P Salcedo 《The EMBO journal》2017,36(13):1869-1887
Bacterial pathogens often subvert the innate immune system to establish a successful infection. The direct inhibition of downstream components of innate immune pathways is particularly well documented but how bacteria interfere with receptor proximal events is far less well understood. Here, we describe a Toll/interleukin 1 receptor (TIR) domain‐containing protein (PumA) of the multi‐drug resistant Pseudomonas aeruginosa PA7 strain. We found that PumA is essential for virulence and inhibits NF‐κB, a property transferable to non‐PumA strain PA14, suggesting no additional factors are needed for PumA function. The TIR domain is able to interact with the Toll‐like receptor (TLR) adaptors TIRAP and MyD88, as well as the ubiquitin‐associated protein 1 (UBAP1), a component of the endosomal‐sorting complex required for transport I (ESCRT‐I). These interactions are not spatially exclusive as we show UBAP1 can associate with MyD88, enhancing its plasma membrane localization. Combined targeting of UBAP1 and TLR adaptors by PumA impedes both cytokine and TLR receptor signalling, highlighting a novel strategy for innate immune evasion. 相似文献
47.
Díaz López E A Morales Ruíz EJ Vargas Ramírez P Hernández Herrera RC Reséndiz Melgar I Brena Hernández JM Loeza Corte 《Phyton》2015,84(2):319-330
The effect of six phosphorus levels (0, 40, 80, 120, 160 and 200 kg/ha) on the duration of cumulative leaf area, biomass and agronomic yield was determined in the maize cultivars: Amarillo Almoloya, Cacahuacintle and Condor in 2010 and 2011. Such cultivars were sown in the Cerrillo Piedras Blancas Mexico. A completely randomized complete block design with factorial arrangement was utilized. High phosphorus levels (120, 160 and 200 kg/ha) positively affected the duration of cumulative leaf area; greatest values were obtained in Cacahuacintle. A greater duration of accumulated leaf area contributes to determine high values of biomass accumulation and grain yield in this cultivar. Leaf area duration appeared to be a useful tool for evaluating different genotypes in a given environment. 相似文献
48.
49.
Saito T Mehanna M Wang X Cusick RD Feng Y Hickner MA Logan BE 《Bioresource technology》2011,102(1):395-398
Carbon cloth anodes were modified with 4(N,N-dimethylamino)benzene diazonium tetrafluoroborate to increase nitrogen-containing functional groups at the anode surface in order to test whether the performance of microbial fuel cells (MFCs) could be improved by controllably modifying the anode surface chemistry. Anodes with the lowest extent of functionalization, based on a nitrogen/carbon ratio of 0.7 as measured by XPS, achieved the highest power density of 938 mW/m2. This power density was 24% greater than an untreated anode, and similar to that obtained with an ammonia gas treatment previously shown to increase power. Increasing the nitrogen/carbon ratio to 3.8, however, decreased the power density to 707 mW/m2. These results demonstrate that a small amount of nitrogen functionalization on the carbon cloth material is sufficient to enhance MFC performance, likely as a result of promoting bacterial adhesion to the surface without adversely affecting microbial viability or electron transfer to the surface. 相似文献
50.
Simon E Brill Anant RC Patel Richa Singh Alexander J Mackay Jeremy S Brown John R Hurst 《Respiratory research》2015,16(1)