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21.
Dependence on exercise intensity of changes in electrolyte secretion from the skin sampled by a simple method 总被引:1,自引:0,他引:1
H Tanaka Y Osaka K Chikamori S Yamashita H Yamaguchi H Miyamoto 《European journal of applied physiology and occupational physiology》1990,60(6):407-411
Secreta from the palm and forearm was sampled for 1-min periods by a new technique, using a glass cylinder. Subjects exercised for 10-min periods at successive intensities of 40%, 50% and 65% VO2max with a leg ergometer operated in the supine position. Changes in the concentrations (values) of Na+, K+ and Cl- in their secreta during exercise were investigated. Significant positive correlations were found between the values of any two electrolytes in samples from the palm or the forearm, but the correlations between values for any one of the three electrolytes from the two sites were not significant. Values for concentrations of the electrolytes were significantly higher in samples from the palm than in those from the forearm at rest, 10 min after the beginning of exercise and at the end of exercise. No significant correlation was found between values for electrolytes in samples from the palm and the exercise intensity, but values for Na+ in samples from the forearm increased stepwise with increase in exercise intensity, and similar tendencies were observed for values of K+ and Cl-. The values for the three electrolytes in samples from the forearm, but not the palm, were significantly correlated with values for blood lactate, the percentage of VO2max and the heart rate. These results suggest that the present technique is suitable for successive samplings of secreta from the forearm, and that values for the electrolytes in samples are useful indices of exercise intensity. 相似文献
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Klaus D. Jürgens Manfred Pietschmann Kazuhiro Yamaguchi Traute Kleinschmidt 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1988,158(4):469-477
Summary The oxygen binding properties of the blood of the camelid species vicuna, llama, alpaca and dromedary camel were measured and evaluated with respect to interspecific differences. The highest blood oxygen affinity, not only among camelids but of all mammals investigated so far, was found in the vicuna (P50=17.6 Torr compared to 20.3–21.6 Torr in the other species). Low hematocrits (23–34%) and small red blood cells (21–30 m3) are common features of all camelids, but the lowest values are found in theLama species. Capillary densities were determined in heart and soleus muscle of vicuna and llama. Again, the vicuna shows exceptional values (3720 cap/mm2 on average in the heart) for a mammal of this body size. Finally, heart weight as percent of body weight is higher in the vicuna (0.7–0.9%) than in the other camelids studied (0.5–0.7%). The possibility that these parameters, measured in New World tylopodes at sea level, are not likely to change considerably with transfer to high altitude, is discussed.In the vicuna, a unique combination of the following features seems to be responsible for an out-standing physical capability at high altitude: saturation of blood with oxygen in the lung is favored by a high blood oxygen affinity, oxygen supply being facilitated by low diffusion distances in the muscle tissue. Loading, as well as unloading, of oxygen is improved by a relatively high oxygen transfer conductance of the red blood cells, which is due to their small size and which compensates the negative effect of a low hematocrit on the oxygen conductance of blood. Blood oxygen transport is presumably favored by two factors: a relatively large heart mass and, as a result of low hematocrit, a low blood viscosity. Both are advantageous for achieving a high maximal cardiac output. 相似文献
25.
Electron microscopy of hepatitis B virus core antigen expressing yeast cells by freeze-substitution fixation 总被引:1,自引:0,他引:1
M Yamaguchi T Hirano K Sugahara H Mizokami M Araki K Matsubara 《European journal of cell biology》1988,47(1):138-143
We have used the freeze-substitution fixation technique for electron microscopy of yeast cells that express the hepatitis B virus core antigen (HBcAg) following transformation with the cloned gene. Abundant spherical particles were found within the transformed cells. These particles had a uniform size and shape, measured about 21 nm in diameter, had electron-lucent centers, and consisted of many subunits. They were localized in both the cytoplasm and the nucleus. None of these particles was found in the cells of the parent strain. Comparison of the HBcAg particles isolated from the yeast cells and the particles within the yeast cells demonstrated that the 21-nm particles were in fact ultrastructurally superimposable on HBcAg. Thus, the HBcAg particles within the yeast cells were similar to the HBcAg particles in human liver tissues infected with hepatitis B virus, not only in their size and appearance, but also in their intracellular localization. These results suggest that the yeast cell has the same machinery for synthesis and intracellular translocation of the HBcAg polypeptides as the human cell. 相似文献
26.
The photosystem II core complex purified from digitonin extractsof spinach chloroplasts was resolved into two chlorophyll-proteincomplexes by digitonin polyacrylamide gel electrophoresis aftertreatment with 1 M potassium thiocyanate. One of the chlorophyll-proteincomplexes resolved consisted of 47, 32, 30 and 9 kDa polypeptidesand the other was complementally composed of only the 43 kDapolypeptide. The former complex was highly active in the photoreductionof 2, 6-dichlorophenol indophenol by 1,5-diphenylcarbazide andretained all of the components responsible for the electrontransport from the secondary electron donor (Z) to the primaryelectron acceptor (QA). EPR signal IIfast and IIslow were alsopreserved in this complex although their hyperfine structureswere largely modified. The complex was estimated to contain1.8 molecules of plastoquinone A as well as 1.5, 3.7 and 3.9molecules of cytochrome b559, pheophytin and ß-carotene,respectively, per QA. These results indicate that potassiumthiocyanate specifically removes the 43 kDa polypeptide fromthe PS II core complex leaving the electron transport systemin an almost intact state. (Received June 17, 1987; Accepted October 23, 1987) 相似文献
27.
Ishikawa Keiko; Kamada Hiroshi; Yamaguchi Isomaro; Takahashi Nobutaka; Harada Hiroshi 《Plant & cell physiology》1988,29(3):461-466
Carrot and tobacco plants were transformed with Agrobacteriumtumefaciens harboring wild-type, aux or cyt Tiplasmids. In tobacco, these wild and mutant Ti plasmids inducedthe formation of non-morphogenic galls, galls with shoots, andgalls with roots, respectively. In carrot, however, transformationwith any of these plasmids resulted in only the formation ofamorphous tumors. Determination of IAA and cytokinin contentsshowed that in tobacco, significantly high amounts of cytokininsor IAA are present in the cells transformed with Ti plasmidspossessing cytokinin or IAA biosynthetic genes, respectively.In carrot, cytokinin contents were also high in the cells transformedwith Ti plasmids having cytokinin biosynthetic genes, whereasIAA contents of the cells were similar regardless of the plasmidsused for transformation. These results suggest that the mechanism regulating IAA metabolismmay be different in tobacco and carrot. (Received June 25, 1987; Accepted February 1, 1988) 相似文献
28.
Hara Takayuki; Nagatani Akira; Yamaguchi Isomaro; Murofushi Noboru; Takahashi Nobutaka; Furuya Masaki 《Plant & cell physiology》1988,29(6):913-918
In the fern Lygodium japonicum, the effect of the exogenousapplication of two gibberellin methyl esters, gibberellin A4methyl ester (GA4Me) and gibberellin A20 methyl ester (GA20Me)on spore germination in the dark and uptake of GA4Me and GA20Meby spores was investigated. Tritiated GA4Me and GA20Me wereprepared and used as radioactive tracers. The activity of GA4Mewas more than 100-fold that of GA20Me for the induction of sporegermination. When treated for 24 h, the activity for inducingspore germination remained after removal of the gibberellinmethyl esters from the medium. The amount of GA4Me taken upby spores was more than three times that of GA20Me throughoutthe 24 h time course of treatment. The uptake of both gibberellinmethyl esters was proportional to the external concentrationfor the range of concentrations between 109 M and 106M. When treated with the tritiated gibberellin methyl estersat 106 M and 107 M for 24 h, most of the gibberellinmethyl esters taken up by the spores were not metabolized. Althoughthe uptake of the two gibberellin methyl esters differed by3- to 5- fold, their abilities to induce spore germination differedby more than 100-fold. Therefore, the difference in the activityof the two gibberellin methyl esters regarding the inductionof spore germination could not be explained solely by the differencein their uptake. (Received January 11, 1988; Accepted May 26, 1988) 相似文献
29.
The primary structure of the mitochondrial energy-linked nicotinamide nucleotide transhydrogenase deduced from the sequence of cDNA clones 总被引:4,自引:0,他引:4
The amino acid sequence of the bovine mitochondrial nicotinamide nucleotide transhydrogenase, which catalyzes hydride ion transfer between NAD(H) and NADP(H) coupled to proton translocation across the mitochondrial inner membrane, has been deduced from the corresponding cDNA. Two clones were isolated by screening a bovine lambda gt10 cDNA library, using two synthetic oligonucleotides and a cDNA restriction fragment as probes. The inserts together covered 3,105 base pairs of coding sequence, corresponding to 1.035 amino acid residues. However, the reading frame at the 5' end was still open. N-terminal sequence analysis of the isolated enzyme indicated the presence of 8 additional residues. Thus, the mature transhydrogenase appeared to have 1,043 amino acid residues and a calculated molecular weight of 109,212. The deduced amino acid sequence of the transhydrogenase contained the sequences of four tryptic peptides that had been isolated from the enzyme. Two of these were the peptides that had been used for construction of the oligonucleotide probes. The other two were tryptic peptides isolated after labeling the NAD-binding site of the transhydrogenase once with [3H]p-fluorosulfonylbenzoyl-5'-adenosine (FSBA), and another time with [14C]N,N'-dicyclohexylcarbodiimide. The FSBA-labeled peptide was found to be located immediately upstream of the [14C]N,N'-dicyclohexylcarbodiimide-labeled peptide, about 230 residues from the N terminus. One of the tryptic peptides used for oligonucleotide probe construction was the same as that labeled with [3H]FSBA when the NAD-binding site was protected from FSBA attack. This peptide, which might be at the NADP-binding site of the transhydrogenase, was located very near the C terminus of the enzyme. The central region of the transhydrogenase (residues 420-850) is highly hydrophobic and appears to comprise about 14 membrane-spanning segments. By comparison, the N- and the C-terminal regions of the enzyme, which contain the NAD- and the putative NADP-binding sites, respectively, are relatively hydrophilic and are probably located outside the mitochondrial inner membrane on the matrix side. There is considerable homology between the bovine enzyme and the Escherichia coli transhydrogenase (two subunits, alpha with Mr = 54,000 and beta with Mr = 48,700), whose amino acid sequence has been determined from the genes (Clarke, D.M., Loo, T.W., Gillam, S., and Bragg, P.D. (1986) Eur. J. Biochem. 158, 647-653). 相似文献
30.