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81.
Glucocorticoids Increase Catecholamine Synthesis and Storage in PC 12 Pheochromocytoma Cell Cultures 总被引:10,自引:4,他引:6
Arthur S. Tischler Robert L. Perlman† Gardiner M. Morse Beth E. Sheard† 《Journal of neurochemistry》1983,40(2):364-370
Abstract: Glucocorticoids, cholera toxin and high plating density all increase the activity of tyrosine 3-monooxygenase (TH) in cultured PC12 pheochromocytoma cells. Glucocorticoids increase enzyme activity in cells treated with cholera toxin and in cells grown at high plating density. Glucocorticoids also increase the content of stored catecholamines in the cells. In cells cultured under routine conditions, glucocorticoids primarily increase the stores of dopamine. The addition of ascorbate to the culture medium increases the storage of norepinephrine in both steroid-treated and untreated cells. Incubation of the cells in media containing 56 n M K+ causes the release of the same percentage of stored dopamine from steroid-treated as from untreated cells. Steroid-treated cells contain more dopamine than do untreated cells and therefore, in response to high K+ , the steroid-treated cells secrete more dopamine than do untreated cells. We conclude that the activity of tyrosine 3-monooxygenase in PC12 cells can be regulated by several distinct mechanisms; that glucocorticoids cause a coordinate increase in TH activity and in catecholamine storage; that steroids increase the storage of catecholamines in a releasable pool; and that the steroid-induced increase in catecholamine storage may result in increased secretion of catecholamines from steroid-treated cells. 相似文献
82.
Venkataraman Amarnath Traci L. Miller Arthur D. Broom 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1983,741(2):224-229
Poly(5-fluoro-2′-deoxyuridylic acid) was synthesized and its properties were compared with those of poly(dT) and poly(dU). It readily complexed with poly(dA). The 1:1 complex melted at about 20°C lower than poly(dA) · poly(dT). A triple-stranded helix, poly(dA)·2 poly(dF5U) was formed only in high salt (2.0 M NaCl). 相似文献
83.
84.
Arthur E. Greene Jesse Charney Warren W. Nichols Lewis L. Coriell 《In vitro cellular & developmental biology. Plant》1972,7(6):313-322
Summary Three mosquito cell cultures designated as Suitor's clone ofAedes aegypti, Culiseta inornata andAedes vexans were shown to be moth by immunological, karyological, and isozyme analyses. The cells reacted with rabbit antimoth serum
but not rabbit antimosquito serum. Chromosome analyses indicated Lepidopteran rather than Dipteran morphology, and three isozyme
systems were confirmative. Any one of these assays would be sufficient to indicate that contamination had occurred and could
be used as a periodic check for identity of cell cultures. Morphology and growth characteristics are also valid criteria to
distinguish between these particular orders of insect cells.
These studies were supported by Grant CA-04953-12 from the National Cancer Institute; General Research Support Grant FR-5582
from the National Institues of Health; and Grant-in-Aid Contract M-43 from the State of New Jersey.
Recipient of Research Career Award 5-K3-16,749. from the National Institutes of Health. 相似文献
85.
Arthur E. Greene Jesse Charney Warren W. Nichols Lewis L. Coriell 《In vitro cellular & developmental biology. Plant》1972,7(5):313-322
Summary Three mosquito cell cultures designated as Suitor's clone ofAedes aegypti, Culiseta inornata, andAedes vexans were shown to be moth by immunological, karyological, and isozyme analyses. The cells reacted with rabbit antimoth serum
but not rabbit antimosquito serum. Chromosome analyses indicated Lepidopteran rather than Dipteran morphology, and three isozyme
systems were confirmative. Any one of these assays would be sufficient to indicate that contamination had occurred and could
be used as a periodic check for identity of cell cultures. Morphology and growth characteristics are also valid criteria to
distinguish between these particular orders of insect cells.
These studies were supported by Grant CA-04953-12 from the National Cancer Institute; General Research Support Grant FR-5582
from the National Institutes of Health; and Grant-in-Aid Contract M-43 from the State of New Jersey.
Recipient of Research Career Award 5-K3-16,749 from the National Institutes of Health. 相似文献
86.
The use of the quantitative nasal culture was investigated as a means of evaluation of new antimicrobial drugs in man. Cyclacillin was somewhat more active in vitro than penicillin G against penicillin G-resistant organisms. Cyclacillin was highly effective in suppressing staphylococci susceptible to penicillin G in nasal carriers but did not suppress staphylococci resistant to penicillin G. Although in previous studies by others cyclacillin was effective in treating mice infected with penicillin G-resistant staphylococci, in the present studies cyclacillin was not effective in suppressing nasal penicillin G-resistant staphylococci in man at doses which markedly suppressed penicillin G-sensitive organisms. 相似文献
87.
The Kinetics of Sodium Transport in the Toad Bladder : I. Determination of the transport pool 总被引:4,自引:3,他引:1
A compartmental model of toad bladder sodium content has been developed, whereby it is possible to measure the four unidirectional fluxes across the opposite faces of the transport compartment, as well as the amount of sodium in the compartment. 24Na is added to the mucosal medium of a short-circuited bladder mounted between halves of a chamber in which the fluid is stirred by rotating impellers. After a steady state is reached, nonradioactive medium is flushed through both sides of the chamber, collected, and counted. The data from each chamber are fitted to sums of exponentials and interpreted in terms of conventional compartmental analysis. Three exponentials are required, with half-times of 0.2, 2.2, and 14.0 min. It is shown that the first of these represents chamber washout, the second the transport pool, and the third a tissue compartment which is not involved in active sodium transport and which does not communicate with the transport pool. The second compartment contains 10.5 µEq of sodium per 100 mg dry weight, an amount equal to approximately 30% of total tissue sodium. The results also indicate, as expected from electrophysiological data, that the mucosal-facing side of the transport compartment is over 10 times as permeable to sodium as the serosal, or pump, side. 相似文献
88.
Arthur Wallace 《Plant and Soil》1971,34(1):121-131
Summary When nonexchangeable absorption of Rb86, Na22, and Cs137 by bush bean (Phaseolus vulgaris L. var. Improved Tendergreen) was determined at different root temperatures and with and without Ca additions or pretreatments,
a strong interaction between temperature and Ca was observed. Ca inhibited Rb86 absorption markedly at low temperatures but had less effect on Cs137. Absorption of Na22 was inhibited by Ca at both low and high temperatures. Little effect for Ca with sometimes a Viets effect was observed at
high temperature for Rb but not for Cs or Na. Ratio pairs of Rb, Ca, and Na were used as an index of similarity of absorption
mechanisms. Cs and Rb, and Na and Rb appeared to be absorbed by different mechanisms at 10−3
M as indicated by temperature and Ca responses. Nitrate-N stimulated uptake of Rb only at high temperature with or without
Ca but not at low temperature. Ca in the pretreatment tended to result in greater long distance transport to shoots of Rb86 and Cs137 for the high temperature but Ca in the test solution slightly decreased the long distance transport. The data are discussed
in terms of the Viets effect and of a possible role of Ca in synthesis of transport proteins. 相似文献
89.
90.
Andrew G. Smith John D. Gilbert W. Arthur Harland Charles J. W. Brooks 《The Biochemical journal》1974,139(3):793-795
Cholest-5-ene-3beta,26-diol, isolated from human brain, was further characterized by oxidation to 3-oxocholest-4-en-26-ol and to 3-oxocholest-4-en-26-oic acid. Identification was achieved by comparison (by t.l.c., g.l.c. and g.l.c.-mass spectrometry) with corresponding reference compounds derived from kryptogenin. 相似文献