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11.
Jamal Bayad Nicole Sabolovic Denyse Bagrel Athanase Visvikis Maria Wellman Gerard Siest 《Cell biology and toxicology》1990,6(2):157-170
Eighteen IgGl monoclonal antibodies (blabs) have been produced against gamma-glutamyl transferase (GGT) from rat kidney. They were specific to the light subunit of the enzyme with affinity constants ranging from 0.3 to 7.5 108 M–1, while they did not react with GGT from other sources i.e. human and pig kidney, rat and guinea pig liver, suggesting species and organ specificity. Two of the blabs (N° 11 and 21) lost their immunoreactivities towards rat kidney GGT in the presence of N-acetyl-neuraminic acid, while immunoreactivities of the other blabs were unchanged. Furthermore, Mabs No 11 and 21 did not react with desialylated rat kidney GGT. These findings suggest that N-acetyl-neuraminic acid is involved in the epitopes recognized by these two Mabs.Abbreviations ELISA
enzyme linked immunosorbent assay
- GGT
gamma-glutamyltransferase
- Mab
monoclonal antibody
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis 相似文献
12.
D.W. Bruno 《FEMS microbiology letters》1988,51(2-3):135-139
Abstract The cell surface hydrophobicity of Renibacterium salmoninarum strains was examined using a salt aggregation method. Those strains which were virulent in the test animal were sticky, auto-agglutinating and possessed a hydrophobic cell surface. Those strains with a low virulence were non-sticky, non-agglutinating and failed to aggregate in a high molar salt. Strains could not be distinguished using biochemical tests. There was no change in hydrophobicity following re-isolation of the bacteria from experimentally infected rainbow trout, Salmo gairdneri . 相似文献
13.
Agnes Janoshazi David M. Ojcius Bruce Kone Julian L. Seifter A. K. Solomon 《The Journal of membrane biology》1988,103(2):181-189
Summary A membrane protein that is immunochemically similar to the red cell anion exchange protein, band 3, has been identified on the basolateral face of the outer medullary collecting duct (MCD) cells in rabbit kidney. In freshly prepared separated rabbit MCD cells, M.L. Zeidel, P. Silva and J.L. Seifter (J. Clin. Invest.
77:1682–1688, 1986) found that Cl–/HCO
3
-
exchange was inhibited by the stilbene anion exchange inhibitor, DIDS (4,4-diisothiocyano-2,2-disulfonic stilbene), with aK
1 similar to that for the red cell. We have measured the binding affinities of a fluorescent stilbene inhibitor, DBDS (4,4-dibenzamido-2,2-disulfonic stilbene), to MCD cells in 28.5 mM citrate and have characterized both a high-affinity site (K
1
s
=93±24 mM) and a lower affinity site (K
2
s
=430±260 nM), which are closely similar to values for the red cell of 110±51 nM for the high-affinity site and 980±200 nM for the lower affinity site (A.S. Verkman, J.A. Dix & A.K. Solomon,J. Gen. Physiol.
81:421–449, 1983). When Cl– replaces citrate in the buffer, the two sites collapse into a single one withK
1
s
=1500±400 nM, similar to the singleK
1
s
=1200±200 nM in the red cell (J.A. Dix, A.S. Verkman & A.K. Solomon,J. Membrane Biol.
89:211–223, 1986). The kinetics of DBDS binding to MCD cells at 0.25 M–1 are characterized by a fast process, =0.14±0.03 sec, similar to =0.12±0.03 sec in the red cell. These similarities show that the physical chemical characteristics of stilbene inhibitor binding to MCD cell band 3 closely resemble those for red cell band 3, which suggests that the molecular structure is highly conserved. 相似文献
14.
The metabolism and mutagenic activation of 2-acetylaminofluorene by human and rat hepatocytes and kidney cells were measured. High performance liquid chromatography was used to separate the 2-acetylaminofluorene metabolites, and a cell-mediated Salmonella typhimurium mutagenesis assay was used to detect mutagenic intermediates. Rat and human differences were observed with cells from both organs and levels of metabolism and mutagenesis were higher in human cells. Within a species, liver and kidney cell differences were also evident, with levels of hepatocyte-mediated metabolism and mutagenesis being greater than kidney cells. Human inter-individual variation was apparent with cells from both organs, but the variation observed was significantly greater in hepatocytes than kidney cells. A knowledge of such differences, including an understanding that they may vary with the chemical being studied, should be useful in the extrapolation of rodent carcinogenesis data to humans.Abbreviations AAF
2-acetylaminofluorene
- AF
2-aminofluorene
- DMSO
dimethylsulfoxide
- HPLC
high performance liquid chromatography
- N-OH-AAF
N-hydroxy-2-acetylaminofluorene
- 1-OH-AAF
1-hydroxy-2-acetylaminofluorene
- 3-OH-AAF
3-hydroxy-2-acetylaminofluorene
- 5/9-OH-AAF
a combination of 5 and 9-hydroxy-2-acetylaminofluorene
- 7-OH-AAF
7-hydroxy-2-acetylaminofluorene
- 8-OH-AAF
8-hydroxy-2-acetylaminofluorene 相似文献
15.
Michael S. Goligorsky David N. Menton Keith A. Hruska 《The Journal of membrane biology》1986,92(2):151-162
Summary In order to examine the possibility of parathyroid hormone-mediated ultrastructural rearrangements in target epithelium, isolated canine renal proximal tubular cells were grown on a collagen-coated semipermeable membrane in a defined medium. Scanning and transmission electron microscopy of these monolayers revealed abundant microvilli. Exposure of the proximal tubular cells to parathyroid hormone resulted in a biphasic changes involving: (1) dramatic shortening and rarefaction of microvilli within 1 min; and (2) recovery of microvillar topography after 5 min. A similar shortening of microvilli was observed following exposure to ionomycin, whereas incubation with cyclic AMP resulted in an elongation of microvilli. Parathyroid hormone stimulated cyclic AMP production and increased cytoplasmic free calcium concentration in cultured proximal tubular cells. Pretreatment of cells with a calmodulin inhibitor abolished the effect of parathyroid hormone on brush border topography. Shortening of microvilli was associated with a disappearance of microvillar core filaments. Staining of F-actin with fluoresceinphalloidin showed that parathyroid hormone resulted in fragmentation of stress fibers. It is concluded that parathyroid hormoneinduced cell activation involves cytoplasmic-free calcium, calmodulin, and the cytoskeleton. 相似文献
16.
Degradation of Boc CCK7 (Boc Tyr1 (SO3H)-Met2-Gly3-Trp4-Met5-Asp6-Phe7-NH2), a fully active analog of CCK8, by purified rabbit kidney neutral metalloendopeptidase (enkephalinase) was studied as a basis for the rational design of potent peptidases-resistant analogs of cholecystokinin. Characterization of the metabolites was performed by HPLC using several elution procedures. Three cleavage sites were evidenced: one major at the Asp6-Phe7 bond and two minor at Gly3-Trp4 and Trp4-Met5 bonds. All cleavages were fully inhibited by thiorphan, a potent inhibitor of enkephalinase. The relative importance of the different cleavages was established using several cholecystokinin analogs. At 25 degrees C the half-disappearance time was 18 min for Boc CCK7, Boc[diNle2,5]CCK7 and 70 min for Boc[diNle2,5 D.Asp6]CCK7. Although, half-life of Boc CCK7 and Boc[diNle2,5]CCK7 were identical, the replacement of Met by Nle, a more hydrophobic aminoacid, greatly favoured the cleavage at the Trp4-Nle5 bond which became the major breakdown. This feature was exemplified by the substitution of L.Asp by D.Asp, preventing the Trp4-Nle5 cleavage, which gave rise to the most enkephalinase-resistant analog in this series. 相似文献
17.
Uterine biopsy in the mare on day 4 post-ovulation causes an acute inflammatory reaction which results in premature luteolysis. In this study, seven mares (4 to 6 years of age) were used in a switchback experimental design to test the hypothesis that in the mare parenterally administered PBZ will block luteolysis induced by uterine biopsy on day 4 post-ovulation. All mares were allowed two normal estrous cycles (range 18 to 24 days). On the first day of estrus of the third estrous cycle each mare was intravenously given 2 grams PBZ (treatment) or 10 ml 0.9% saline (control) daily until signs of estrus were exhibited. The day of ovulation (day 0) was determined by rectal palpation and subsequently verified by peripheral plasma progesterone concentrations. On day 4 following ovulation all mares were subjected to uterine biopsy, and subsequent estrus detection was performed daily using an andro-genized gelding. A total of 19 estrous cycles (ten for PBZ treatment and nine for controls) were evaluated. Mean number of days (+/-SE) from uterine biopsy to induced estrus was 5.00+/-0.16 for control cycles and was significantly different (P<0.025) when compared with 9.20+/-0.34 days for treatment cycles. Results of this study suggest that PBZ can block luteolysis in the mare induced by uterine biopsy on day 4 post-ovulation, possibly as a result of accumulating PBZ in acutely inflamed uterine tissue and inhibiting prostaglandin synthesis. 相似文献
18.
19.
In vitro growth and differentiation of human kidney tubular cells on a basement membrane substrate 总被引:4,自引:0,他引:4
An Hang Yang Jeanine Gould-Kostka Terry D. Oberley 《In vitro cellular & developmental biology. Plant》1987,23(1):34-46
Summary Kidney cortical tubular cells, mainly proximal tubular cells, isolated from human kidney and grown either on a basement membrane
substrate in chemically defined medium or on plastic in serum-supplemented medium, had substantial proliferative potential
and could be propagated for more than 10 generations or 8 passages before senescence. Basement membrane produced on a plastic
substrate by the HR-9 endodermal cell line could replace serum supplementation in promoting tubular cell growth. Tubular cells
grown on an HR-9 basement membrane substrate exhibited stable epithelial morphology over an extended period of time; in the
presence of 5% serum they differentiated into organized structures such as hemicysts and cell cords. Cells grown on plastic
failed to differentiate and gradually degenerated. Tubular cells on HR-9 basement membrane were characterized by densely packed
microvilli, abundant rough endoplasmic reticulum and free polysomes, basal cell membrane interdigitations, a well-developed
endocytotic apparatus, and conspicuous junctional complexes—all features of the proximal tubular cell. Compared with cells
on plastic substrate, there were higher levels of the brush border enzymes γ-glutamyl transpeptidase,l-leucine aminopeptidase, and alkaline phosphatase in cells maintained on an HR-9 basement membrane substrate, further supporting
the conclusion that a basement membrane substrate promoted differentiation of tubular cells. These data and morphological
observations indicate that a basement membrane substrate can promote growth and both functional and morphologic differentiation
of human kidney tubular cells.
This work was supported by the Veterans Administration. 相似文献
20.
The murine “housekeeping” enzyme, cytosolic NADP-isocitrate dehydrogenase (E.C. 1.1.1.42) (genetic locus:Idh-1), exhibited a complex pattern of allele-specific expression. Protein electrophoresis on cellulose-acetate gels and determination of relative enzymatic activity by means of densitometry revealed that in heart tissue (but not liver tissue) of certain hybrid crosses the AA-homodimer was underrepresented relative to total enzymatic activity, and the degree of underrepresentation changed during development. In mixtures of homozygous tissue extracts of heart tissue (but not liver tissue) the AA-homodimer was underrepresented relative to the BB-homodimer. Relative activity of allelic isozymes varied as a function of tissue (heart versus liver), age, and the parental source of the Idh-1a allele, but did not vary as a function of sex. Allele-specific expression was also exhibited in kidney tissue of the same animals. In adult male kidney tissue extracts from heterozygotes, the AA-hornodimer was underrepresented relative to total enzymatic activity; in adult female kidney tissue extracts from heterozygotes, a more codominant phenotype was observed. Tissue extracts from immature hybrid animals exhibited a phenotype midway between the adult male and adult female phenotypes. Tissue extracts from castrated males exhibited a phenotype equivalent to that seen in females. Relative activity of allelic isozymes in kidney varied as a function of age and sex, but did not vary as a function of the parental source of the Idh-1a allele. While cytosolic NADP-IDH is a “housekeeping” enzyme, expressed in multiple tissues of the mouse, differences in the relative intensities of allelic isozyme bands provide evidence for tissue- and stage-specific regulatory variation. 相似文献