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11.
N. Cohen G. Weber B.L. Banner A.F. Welton W.C. Hope H. Crowley W.A. Anderson B.A. Simko M. O'Donnell J.W. Coffey C. Fiedler-Nagy C. Batula-Bernardo 《Prostaglandins & other lipid mediators》1984,27(4):553-562
The syntheses and biological activity of (all
)-7,7-dimethyl-5-8,- 11,14-eicosatetraenoic acid, (all
)-7,7,-dimethyl-5,8,11-eicosatrienoic acid, (
,
-7,7-dimethyl-5,8-eicosadienoic acid, (all
)-10,10-dimetyl- 5,8,11,14-eicosatetraenoic acid, (all
-10,10-dimethyl-5,8,11-eicosatrienoic acid, and
.-(
,
-15-hydroxy-7,7-dimethyl-5,8-eicosadienoic acid are described. These arachidonic acid analogs are all inhibitors of ionophore-induced SRS-A biosynthesis in rat peritoneal cells. Their mode of action may involve inhibition of phospholipase A2 rather than Δ5-lipoxygenase. These compounds failed to exhibit significant activity in an
model designed to detect inhibitors of antigen-induced, leukotriene-mediated bronchoconstriction is sensitized guinea pigs. 相似文献
12.
A simple one-step procedure is described on the isolation of androgen glucuronides from various rat tissues. This procedure uses polyacrylamide gel electrophoresis, and permits a quantitative isolation of a single band containing the total androgen glucuronides without the contamination of free androgens and androgen sulfates. This procedure was used to determine the ability of various tissues of the rat to form androgen glucuronides directly when they were incubated with 1,2-[3H]-testosterone (0.1 μM) . Of eleven organs studied, only the accessory sex organs (ventral prostate, seminal vesicle, and coagulating gland), liver, and kidney were capable of forming androgen glucuronides. At the end of a one-hour incubation period, approximately 1% of the total radiolabeled steroids in the prostatic tissue minces were in the form of glucuronide conjugates. The predominant androgen glucuronide formed in the accessory sex organs was 5α-androstane-3α,17β-diol 17β-d-glucuronide. This is in contrast to the rat liver and kidney in which testosterone glucuronide was the predominant conjugate.A similar amount of labeled glucuronide conjugates was formed from either [3H]-testosterone, [3H]-dihydrotestosterone or [3H]-androstenedione, whereas negligible amount of steroid conjugates was formed from [3H]-cortisol. The formation of androgen glucuronides requires metabolically active tissues; furthermore, the conjugation process was inhibited by the antiandrogen, cyproterone acetate, or by metabolic inhibitors, such as oligomycin or N-ethylmaleimide. 相似文献
13.
Summary A cytochemical study involving enzymic digestions, chemical extractions and specific staining methods was made of the host-parasite interface in downy mildew infected pea plants. Enzymic hydrolysis revealed both the penetration and extrahaustorial matrices to have a proteinaceous component, possibly glycoprotein, while the extrahaustorial matrix had cellulose as an additional constituent. Intense silver proteinate staining of both matrices following a prolonged incubation in thiocarbohydrazide indicated the presence of complex carbohydrates. Carbohydrates were confirmed as constituents of both matrices following the complete suppression of silver staining using the aldehyde blocking agents dimedone and sodium borohydride. Both matrices also exhibited a marked affinity for phosphotungstic acid. Following acetylation a complete elimination of phosphotungstate staining resulted, again indicating carbohydrate as a constituent of both matrices. Digestion of the fungal cell wall using an enzyme which hydrolyses -1,3-glucans showed that these carbohydrates are important in its construction. However such enzyme treatment did not affect the structural integrity of either the penetration or extrahaustorial matrix. The extrahaustorial membrane exhibited negligible staining with phosphotungstic-chromic acid treatment, while the host plasmalemma showed a positive but variable staining reaction. A very intense staining reaction characterized the fungal plasmalemma after staining with either phosphotungstic-chromic acid, phosphotungstic acid or silver proteinate. 相似文献
14.
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16.
The effect of extracellular matrix interactions on morphologic transformation in vitro 总被引:1,自引:0,他引:1
K J Pienta B C Murphy R H Getzenberg D S Coffey 《Biochemical and biophysical research communications》1991,179(1):333-339
There is emerging evidence that the structure and function of a cell is dependent in part on the contacts that cells make with the extracellular matrix. We report here the effect of extracellular matrices secreted from both normal and tumor cells have on the structure of normal rat kidney epithelial cells. Normal rat kidney cells plated on the basement membrane secreted by tumor cells adopt a morphology and phenotype which closely resembles a Kirsten-ras transformed normal rat kidney cell. This morphologic transformation was not observed for cells plated on individual extracellular matrix components or on basement membrane secreted by normal placenta cells. This suggests that tumor derived basement membrane has unique characteristics which may cause morphologic transformation of normal rat kidney cells. 相似文献
17.
Human lymphocyte guanylate cyclase activities are increased in a dose-dependent fashion by incubation of intact cells with phorbol myristate acetate, a tumor promoter and lymphocyte mitogen. Increased activity is detectable after 1 minute, and peak membrane-bound and soluble forms of guanylate cyclase occur after 10- and 30-minute exposure to phorbol myristate acetate, respectively. The soluble form is stimulated much more than the membrane form. Enzyme activities measured in the presence of either Ca2+, Mg2+, or Mn2+ are elevated to similar degrees. Comparisons of phorbol and a series of its diesters revealed a good correlation between the capacities for guanylate cyclase stimulation, lymphocyte mitogenesis, and tumor promotion. 相似文献
18.
19.
Abstract A class of very potent nucleoside transport inhibitors is present in two molecular forms around physiological pH. We investigated whether the monoprotonated or the unionized species of these molecules binds to this camer protein with higher affinity. 相似文献
20.
Christopher I Keeling Macaire MS Yuen Nancy Y Liao T Roderick Docking Simon K Chan Greg A Taylor Diana L Palmquist Shaun D Jackman Anh Nguyen Maria Li Hannah Henderson Jasmine K Janes Yongjun Zhao Pawan Pandoh Richard Moore Felix AH Sperling Dezene P W Huber Inanc Birol Steven JM Jones Joerg Bohlmann 《Genome biology》2013,14(3):R27