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1.
涎腺导管上皮细胞体外感染HCMV模型的建立 总被引:5,自引:0,他引:5
目的 建立涎腺导管上皮细胞体外人巨细胞病毒 (HCMV)感染模型。方法 用免疫细胞化学方法初步鉴定涎腺导管上皮细胞 (HSG)角蛋白 8(cytokeratin 8,CK8)和角蛋白 18(CK18)抗原的表达 ;观察HCMV感染HSG后导致的病变 ;观察宿主细胞中病毒颗粒的超微结构 ;用RT PCR及nest RT PCR检测HCMVIE1(即刻早期 1) /IE2基因的转录 ;用免疫细胞化学法检测HCMV感染细胞中IE1/IE2蛋白的表达。结果 呈上皮样贴壁生长的HSGCK8和CK18阳性表达 ;HCMV感染后 12小时 ( 12h .p .i.)即可见细胞病变 ,6 0h .p .i.CPE已极为明显 ,72h .p .i.绝大部分细胞出现病变。感染的HSG细胞在细胞核、内质网、细胞质中出现数量不等的 3种不同形态的疱疹病毒样颗粒。宿主细胞中可检测到HCMVIE1/IE2的转录以及IE1/IE2蛋白的表达。结论 成功建立了涎腺导管上皮细胞体外HCMV感染模型 相似文献
2.
A. Skálová Michal Michal Aleš Ryška Roderick H. W. Simpson Zdenčk Kinkor Jiří Walter Ilmo Leivo 《Virchows Archiv : an international journal of pathology》1999,434(6):537-546
Twenty oncocytic myoepitheliomas (MEs) and pleomorphic adenomas (PAs) were composed of interlacing fascicles of swollen spindle-shaped
or/and epithelioid oncocytic myoepithelial cells showing intense finely granular immunoreactivity with anti-mitochondrial
antibody. Focal vacuolation of the cytoplasm of oncocytic myoepithelial cells and their gradual transition into sebaceous
metaplasia were observed in 3 cases. Another unusual feature found in 5 cases was the presence of slit-like adenomatoid spaces
lined with double-layered oncocytic myoepithelium closely resembling Warthin’s tumour. The nuclei of oncocytic cells were
characterized by enlargement, hyperchromasia and polymorphism, which should not be confused with malignancy. Oncocytic change
in myoepithelial cells in MEs and PAs can cause pitfalls in the differential diagnosis of salivary gland tumours. We describe
some unusual histological features associated with onococytic metaplasia in benign myoepithelial cell-derived salivary gland
tumours, hoping to help to avoid the overdiagnosis of malignancy.
Received: 24 September 1998 / Accepted: 31 January 1999 相似文献
3.
Keratin 14 immunoreactive cells in pleomorphic adenomas and adenoid cystic carcinomas of salivary glands 总被引:4,自引:0,他引:4
Ogawa Y Toyosawa S Ishida T Ijuhin N 《Virchows Archiv : an international journal of pathology》2000,437(1):58-68
Our recent study of developing myoepithelial cells (MECs) in rat salivary glands demonstrated that developing MECs begin to
express α-smooth muscle actin (αSMA) first and, thereafter, keratin 14. Therefore, it is unlikely that duct basal cells expressing
keratin 14 alone are immature or undifferentiated MECs. In this study we carried out immunohistochemistry of pleomorphic adenomas
and adenoid cystic carcinomas including normal salivary glands using monoclonal antibodies to keratin 14, smooth muscle proteins
and keratin 19. The smooth muscle proteins examined included αSMA, h-caldesmon and h1-calponin; h1-calponin was observed in
keratinocytes and nerve fibers, indicating that the protein is not specific to smooth muscle, whereas αSMA and h-caldesmon
turned out to be highly specific markers for smooth muscle cells in normal tissues. In normal glands, MECs were positive for
both keratin 14 and smooth muscle proteins (αSMA and h-caldesmon). Non-MEC cells were essentially devoid of smooth muscle
proteins. Non-MEC duct basal cells expressed keratin 14 with or without keratin 19, and luminal cells keratin 19 with or without
keratin 14. This suggests that the keratin 14-positive, smooth muscle proteins-negative duct basal cells are luminal cell
progenitors. Luminal cells in tubular structures of both tumors were positive for keratin 19 with or without keratin 14. Nonluminal
peripheral cells of pleomorphic adenomas were mostly positive for keratin 14, and a small fraction of them expressed smooth
muscle proteins. Conversely, peripheral cells of adenoid cystic carcinomas were mostly positive for smooth muscle proteins,
and some of them expressed keratin 14. These results strongly suggest (1) that the luminal cell progenitors transform into
major constituents of pleomorphic adenoma cells with keratin 14 but not smooth muscle proteins, and (2) that the peripheral
cells of adenoid cystic carcinoma are derived from undifferentiated MECs. Solid structures of pleomorphic adenomas were formed
by proliferation of the peripheral cells. MECs were observed only occasionally in the periphery. Solid and cribriform structures
of adenoid cystic carcinomas were formed by proliferation of the luminal cells. MECs were observed in the periphery and around
the pseudocyst.
Received: 2 December 1999 / Accepted: 12 January 2000 相似文献
4.
Reconstruction of pleomorphic adenoma of the salivary glands in three-dimensional collagen gel matrix culture 总被引:1,自引:0,他引:1
Fujita Y Yoshida T Sakakura Y Sakakura T 《Virchows Archiv : an international journal of pathology》1999,434(2):137-143
The morphogenesis of salivary gland pleomorphic adenoma was examined in vitro using three-dimensional (3-D) collagen gel
culture. Pleomorphic adenoma cells were isolated from three parotid gland tumours and cultured as monolayers, after which
they were subcultured in floating-collagen gel sandwiches. Cells cultured in both conditions were immunohistochemically characterized
and compared using antibodies against various proteins representative of each histological component of salivary glands. Monolayers
had myoepithelial characteristics, being positive for vimentin and α-smooth muscle actin. In collagen gels, however, the cells
assembled in epithelial nests, showing an architecture similar to that of pleomorphic adenoma. The nests were composed of
duct-lining epithelial cells that were positive for epithelial markers, surrounded by myoepithelial cells. Collagen gel culture
induces multi-directional differentiation of adenoma cells, suggesting that pleomorphic adenomas originate from stem or reserve
cells.
Received: 26 March 1998 / Accepted: 1 September 1998 相似文献
5.
Yasunori Takeda Goro Ishikawa 《Virchows Archiv : an international journal of pathology》1982,399(1):41-48
Summary Crystalloids found in salivary duct cysts of the human parotid gland were examined by scanning electron microscopical observations with electron probe X-ray microanalysis. The cystic spaces were filled with numerous crystalloids which had a variety of forms with slight eosinophilic and glassy appearance. Scanning electron microscopically, crystalloids were hexagonal and rhombohedral in shape, and cutting the surface showed a polycyclic structure or regular parallel lamination. By electron probe X-ray microanalysis, sulphur was the only detected element. The present study suggests that crystalloids resulted from deposition from supersaturated saliva containing sulphur containing compounds into the cystic lumen or into epithelial cytoplasm. 相似文献
6.
J. P. Klussmann E. Krueger T. Sloots Z. Berneman G. Arnold G. R. F. Krueger 《Virchows Archiv : an international journal of pathology》1997,430(5):417-426
Human herpesvirus 7 (HHV-7) was grown in a CD4+ lymphoblastic cell line (SupT1) and in cord blood mononuclear cells (CBMC).
Virus infection was demonstrated by immunohistology with positive control sera, with monoclonal antibodies and by in situ
hybridization for viral DNA. Cytopathic effects following HHV-7 infection generally resemble those after HHV-6 infection but
are less pronounced. The ultrastructural appearance of HHV-7 and the replicative stages were similar to those described by
Kramarsky and Sander for HHV-6. There were some minor discrepancies, including quite an extensive and space-filling tegument,
a slightly different structure of the nucleoid, the frequent finding of nucleocapsids without any visible core and apparently
scarce or delicate spikes on the envelope. These differences may suggest HHV-7 rather than HHV-6, but this finding needs confirmation.
Mature HHV-7 particles measured 170 nm in diameter, with nucleocapsids of 90–95 nm and a tegument of about 30 nm.
Received: 30 September 1996 / Accepted: 8 January 1997 相似文献
7.
D. Accili Maria Gabriella Gabrielli Giovanna Menghi Giovanni Materazzi 《Anatomy and embryology》1999,199(2):113-123
The developmental expression of salivary glycoconjugates was investigated in the rat submandibular and sublingual glands
by conventional and lectin histochemistry. By the time of the first differentiation of secretory structures, in spite of similar
morphological features, a different histochemical reactivity was detected, accounting for a relevant content of neutral glycoconjugates
in the submandibular gland and the occurrence of both neutral and acidic glycoconjugates in the sublingual one. The use of
lectins allowed the main changes of secretory components to be noted around gestational day 18. DBA and WGA lectins seemed
to act as pre- and post-natal development markers while Con A lectin was indicative of post-natal differentiation. Taken together,
data from lectin histochemistry indicated the transitional occurrence of glycoconjugates, probably involved in temporally
restricted functions, as well as the co-existence of different secretory components that might also reflect maturational changes
of single products.
Accepted: 31 July 1998 相似文献
8.
L. Alos R. Carrillo J. Ramos J. M. Baez C. Mallofre P. L. Fernandez A. Cardesa 《Virchows Archiv : an international journal of pathology》1999,434(4):291-299
Three cases of epithelial-myoepithelial carcinoma (EMC) with coexisting areas of high grade carcinoma are reported. In two
of the cases there was a previous recurrence, and in all three patients there had been a sudden increase in size before final
surgery. The typical ductal and myoepithelial components of EMC showed the usual biphasic pattern and the expected immunophenotypes,
with expression of wide spectrum cytokeratins, Cam 5.2 and EMA in the ductal part, and muscle-specific actin, smooth muscle
actin, S-100 protein, vimentin and cytokeratins in the myoepithelial component. These areas also had a low mitotic count and
low proliferation rate as measured by immunohistochemistry and by flow cytometry. Conversely, areas of high-grade tumour had
the features of a large cell carcinoma, with focal mucin secretion in two cases. This high-grade component showed an epithelial
immunophenotype in two cases, and was negative for all tested markers in the third one. The mitotic counts and the proliferation
rates were much higher in these anaplastic areas. One of the patients died 3 months after treatment; another developed lymph
node metastases 1 year later and was alive after 6 years of follow-up. The third patient was alive without evidence of disease
7 months after wide surgical resection of the tumour. The possibility of anaplastic transformation in EMC makes thorough sampling
mandatory in this type of neoplasm.
Received: 14 Octobre 1998 / Accepted: 7 December 1998 相似文献
9.
Michal M Skálová A Mukensnabl P 《Virchows Archiv : an international journal of pathology》2000,437(4):465-468
We describe a 45-year-old man who had a 2-year history of a slowly enlarging tumor in the left parotid gland. Histologically,
the tumor was a mucinous cystadenoma with focal apocrine differentiation, which revealed a widespread invasive micropapillary
adenocarcinoma component. A rim of lymphoid tissue surrounded the margins of the micropapillary carcinoma. The invasive micropapillary
adenocarcinoma component was morphologically identical with the invasive micropapillary carcinoma of the mammary gland. The
tumor is different from so-far recognized salivary gland tumor entities.
Received: 25 October 1999 / Accepted: 13 June 2000 相似文献
10.
Immunohistochemistry of myoepithelial cells during development of the rat salivary glands 总被引:2,自引:0,他引:2
Y. Ogawa Shinobu Yamauchi Akio Ohnishi Reiko Ito Naokuni Ijuhin 《Anatomy and embryology》1999,200(2):215-228
Using a battery of monoclonal antibodies specific for rat proteins, immunohistochemistry was carried out on the developing
myoepithelial cells (MECs) of the rat major salivary glands. The proteins examined were α-smooth muscle actin (αSMA), h1-calponin
(calponin), keratin 14 (K14), β subunit of S-100 protein (S-100β), vimentin and glial fibrillary acidic protein (GFAP). The
MECs exhibited immunoreactivity for αSMA, calponin and K14, but not that for S-100β, vimentin and GFAP. Immunoreactivity for
αSMA appeared in the MECs from the time when the microfilaments were initially deposited in these cells, i.e., at 20 days
in utero in the sublingual and submandibular glands and at birth in the parotid gland. Calponin immunoreactivity was seen
1 day earlier than αSMA. The appearance was almost at the same time as the onset of the MEC differentiation in each gland.
A small number of the MECs expressed weak K14 immunoreactivity from the time when the acinus-intercalated duct structure was
established, i.e., at 21 days in utero in the sublingual gland, at 5 days after birth in the perotid gland and after 5 weeks
post-natally in the submandibular gland. In addition, K14 immunoreactivity was observed in the basal cells of the striated
and excretory ducts. The first appearance of K14 in these cells again coincided with the emergence of the duct system in each
gland, i.e., at 20 days in utero in the sublingual gland, at 21 days in utero in the submandibular gland and at 3 days after
birth in the parotid gland. Finally, the MECs in all the glands were found to redistribute as the acini matured. As the acini
grew rapidly during the weaning period in the parotid and the sublingual glands, the MECs ceased to surround the acini. Thereafter,
they disappeared from the acini in the parotid gland, whereas they reappeared in the sublingual gland. In the submandibular
gland, the MECs were confined to the terminal tubules until 4 weeks after birth. Thereafter, the acini were established and
invested by the MECs. In conclusion, immunohistochemistry of calponin and αSMA is a useful tool for identification of the
MEC during its earliest differentiation, which has hitherto been possible only electron microscopically. In addition, it is
suggested that the MEC is heterogeneous and the functionally differentiated MEC appears after weaning around acini of the
mucous and seromucous glands.
Accepted: 11 January 1999 相似文献
11.
A polarized salivary cell monolayer useful for studying transepithelial fluid movement in vitro 总被引:2,自引:0,他引:2
Xinjun He Gemma A. J. Kuijpers Gertrud Goping Jill A. Kulakusky Changyu Zheng Christine Delporte Chung-Ming Tse Robert S. Redman Mark Donowitz Harvey B. Pollard B. J. Baum 《Pflügers Archiv : European journal of physiology》1998,435(3):375-381
There are no reported, convenient in vitro models for studying polarized functions in salivary epithelial cells. Accordingly,
we examined three often-used salivary cell lines for their ability to form a polarized monolayer on permeable, collagen-coated
polycarbonate filters. Only the SMIE line, derived from rat submandibular gland, had this ability. The SMIE cell monolayer
exhibited junctional complexes, with a tight-junction-associated protein, ZO-1, localized to cell–cell contact areas. The
Na+/K+-ATPase α1-subunit was detected predominantly in the basolateral membranes, while the Na+/H+ exchanger isoform 2 appeared primarily in the apical membranes. Using adenovirus-mediated cDNA transfer, SMIE cells were
shown to be capable of routing marker proteins (β-galactosidase ± a nuclear targeting signal, α1-antitrypsin, aquaporin-1)
to appropriate locations. Furthermore, this salivary cell monolayer provided a convenient tool for studying aquaporin-1-mediated,
osmotically directed, transepithelial fluid movement in vitro. Thus, SMIE cells appear to be a useful experimental model with
which to study some polarized functions in a salivary epithelial cell line.
Received: 16 September 1997 / Accepted: 17 September 1997 相似文献
12.
Using cell-free reactions, we investigated the role of the 5′ cloverleaf (5′CL) and associated C-rich sequence in Coxsackievirus B3 RNA replication. We showed that the binding of poly(C) binding protein (PCBP) to the C-rich sequence was the primary determinant of RNA stability. In addition, inhibition of negative-strand synthesis was only observed when PCBP binding to both stem-loop ‘b’ and the C-rich sequence was inhibited. Taken together, these findings suggest that PCBP binding to the C-rich sequence was sufficient to support RNA stability and negative-strand synthesis. Mutational analysis of the three conserved structural elements in stem-loop ‘d’ showed that they were required for efficient negative- and positive-strand synthesis. Finally, we showed an RNA with a 5′ terminal deletion (Δ49TD RNA), which was previously isolated from persistently infected cells, replicated at low but detectable levels in these reactions. Importantly, the critical replication elements identified in this study are still present in the Δ49TD RNA. 相似文献
13.
S. Fatherazi K. T. Izutsu J. R. Martinez 《Pflügers Archiv : European journal of physiology》1996,433(1-2):116-122
Using the whole-cell patch-clamp technique, we investigated developmental changes in the expression of an acetylcholine-
(Ach-) activated Cl–conductance in rat submandibular acinar cells. ACh induced an oscillatory inward current in cells isolated from animals older
than 5 weeks, but not in animals less than 2–3 weeks of age. The current/voltage (I/V) relationship of the ACh-induced current was that of an outward rectifier, and the current was inhibited by intracellular
BAPTA, a Ca2+ buffer, indicating the current was Ca2+ activated. The ACh-induced current was also blocked in the presence of DPC and SITS, two Cl–current inhibitors in other tissues. Ionomycin mimicked the effect of ACh but in a nonoscillatory fashion. The appearance
of the ionomycin-induced currents was also age related, as the current was not observed to occur in animals less than 2–3
weeks old. Since both ACh and ionomycin significantly increase cytosolic [Ca2+] in the acinar cells of young animals, the correlation between the age dependence of the ACh-activated Cl–current and the ionomycin-activated Cl–current responses suggests that the lack of responsiveness observed in the young animals is due to the absence of Ca2+-activated Cl–channels, rather than to a deficiency of a cellular mediator.
Received: 8 July 1996 / Received after revision and accepted: 2 September 1996 相似文献
14.
The parathyroid glands of the adult rat harbor a number of neuroendocrine markers, biologically active peptides and ”classical”
neuromessengers in addition to parathyroid hormone (PTH). Their appearance during parathyroid development is, however, not
known. In the present study we have examined several neuroendocrine markers and neuromessengers in the parathyroid glands
of the developing rat [embryonic stage 21(E21), newborn, 1, 2, 3, 4 week old, and adult rats] using immunocytochemistry. Chromogranin
A- and PTH-mRNA were also examined by in situ hybridization and the mRNA levels were quantitated by computerized image analysis.
Protein gene product 9.5- and synaptophysin-containing nerve fibers appeared already before birth and then gradually increased
in number postnatally, and at the age of 4 weeks the nerve fibers were moderate in number to numerous. Nerve fibers containing
calcitonin gene-related peptide, neuropeptide Y and vasoactive intestinal polypeptide also increased gradually in number,
while galanin- , substance P- and tyrosine hydroxylase-containing fibers remained few throughout development. The glandular
cells expressed chromogranin A, pancreastatin and PTH already before birth. The levels of chromogranin A- and PTH-mRNA were
low at E21 and increased markedly at birth; chromogranin A mRNA levels had increased even more at 1 week postnatally. Three
to 4 weeks after birth the levels of PTH- and chromogranin A mRNA again increased, then stabilized at a slightly lower level
in the adult rat. Our findings demonstrate that the parathyroid glands of rat are already innervated and express PTH and chromogranin
A before birth and that the density of peptide-containing nerve fibers changes during development. The stepwise increases
of PTH- and chromogranin A mRNAs during development indicate marked changes in parathyroid activity occurring at birth and
at weaning.
Accepted: 21 January 1997 相似文献
15.
Alterations of basement membrane in di-isopropanolnitrosamine- induced carcinogenesis of the rat thyroid gland: an immunohistochemical study 总被引:2,自引:0,他引:2
Lu S Huang M Kobayashi Y Komiyama A Li X Katoh R Kawaoi A 《Virchows Archiv : an international journal of pathology》2000,436(6):595-601
Alterations of basement membrane (BM) in di-isopropanolnitrosamine (DIPN)-induced carcinogenesis of the rat thyroid gland
were examined by means of immunohistochemical localization of collagen type IV (CN-IV), laminin (LN), and fibronectin (FN)
in pre-nodular and nodular thyroid lesions, correlating with the morphogenesis and proliferative activity of these lesions.
Adult male rats of the Wistar strain were injected s.c. in the back with DIPN, and the thyroid glands were removed at the
15th and 30th week of treatment. Each of 133 thyroid lesions was histochemically analyzed. The follicular epithelial BM as
revealed by CN-IV and LN was discontinued or completely lost during the progression of thyroid lesions from pre-nodular to
nodular lesions and finally overt carcinomas. At the same time, the BM of vascular endothelial cells demonstrated a loss of
dense capillary networks of follicles, a sinusoidal dilatation and, predominantly in carcinomas, development of interstitial-type
blood vessels. However, FN, which was hardly stained in the normal thyroid tissue, was remarkably deposited in the interstitium
of invasive carcinomas. These observations strongly suggested that alterations of BM structure play a key role in the morphogenesis
of rat thyroid tumors, and that the expression of FN is an important step in the invasive growth of thyroid tumors.
Received: 12 October 1999 / Accepted: 30 December 1999 相似文献
16.
Möck M Schwarz C Wahle P Thier P 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1999,124(4):529-532
As clearly indicated by our electrophysiological work, GABAergic inhibition plays a powerful role in the pontine nuclei (PN),
the major link between cerebral cortex and the cerebellum. Using the technique of in situ hybridization for the mRNA encoding
for the γ-aminobutyric acid (GABA)-synthesizing isoenzyme glutamic acid decarboxylase67 (GAD67), we demonstrate here the total absence of potentially GABAergic neurons from the rat PN. This negative finding supports
the notion that GABAergic inhibition in the PN of rats, unlike that of higher mammals, is exclusively based on extrapontine
GABAergic afferents.
Received: 20 August 1998 / Accepted: 29 October 1998 相似文献
17.
M.-Y. Lee S.-L. Shin S.-H. Han M.-H. Chun 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1999,128(3):309-314
The birthdates of GABAergic amacrine cells in the rat retina were investigated by immunocytochemistry using anti-GABA and
anti-bromodeoxyuridine (BrdU) antisera. The ratio of co-localization of GABA to BrdU increased gradually from embryonic-day
13 (E13) and showed a peak value on E18 in the central retina and on E20 in the periphery. After birth, until postnatal-day
3 (P3), a few co-localized cells were observed in the inner nuclear layer (INL). However, in the peripheral retina, co-localized
cells were observed in the INL and ganglion cell layer until P5. Our results suggest that the birthdates of GABA-immunoreactive
cells vary, depending on cell-type and that there is a temporal lag in the GABA-immunoreactive cell production in the peripheral
retina relative to the central retina.
Received: 11 January 1999 / Accepted: 20 April 1999 相似文献
18.
Induction of adenocarcinoma containing myoepithelial cells in rat submandibular gland by 7,12-dimethylbenz(a)anthracene 总被引:1,自引:0,他引:1
Ogawa Y Wan F Toyosawa S Ijuhin N 《Virchows Archiv : an international journal of pathology》2000,437(3):314-324
In an attempt to induce adenocarcinoma containing myoepithelial cells (MECs) in the rat submandibular gland, we injected 7,12-dimethylbenz(a)anthracene
(DMBA) dissolved in acetone into the glands of rat pups at the age of 10 days. In both male and female pups, the glands, including
their developing terminal secretory units, contained far greater numbers of cells positive for proliferating cell nuclear
antigen (PCNA) than did adult glands. A single administration of 1% DMBA (0.05 ml/130 g b.w.) did not produce adenocarcinoma,
but did induce occasional sarcomas, such as rhabdomyosarcoma and fibrosarcoma, in 2 months. Most glands regenerated with minimal
scar formation. Microscopically, these glands were atypical in that they contained increased numbers of PCNA-positive cells,
underdeveloped granular ducts, and striated ducts surrounded by MECs positive for alpha smooth muscle actin (αSMA). Though
these features were also observed in the regenerated glands after acetone injection, the number of PCNA-positive cells was
relatively high in the glands of DMBA-treated females, especially in the terminal secretory unit. The second DMBA injection
at 10 weeks of age produced adenocarcinoma made up of αSMA-positive MECs and keratin 19-positive duct cells. Such MEC-associated
adenocarcinoma was induced in the glands of more than half the female but not the male animals. Replacement of either of the
double DMBA treatments with acetone, or DMBA treatment, single or double, of adult glands did not produce adenocarcinoma,
but did produce sarcoma and squamous cell carcinoma. These results suggest that (1) at least two genetic mutations are necessary
for induction of adenocarcinoma with MECs in the rat submandibular gland, (2) the mutation is efficiently introduced to pup
glands whose terminal secretory units exhibit extreme proliferative activity, and (3) the second mutation is difficult to
introduce in male glands, whose proliferative activity is relatively low, and/or transformed cells need some female hormone
after the mutation to propagate.
Received: 21 December 1999 / Accepted: 10 March 2000 相似文献
19.
J. T. Seo Y. J. Kim R. M. Case M. C. Steward 《Pflügers Archiv : European journal of physiology》1997,435(1):74-81
To investigate the role of Cl– in the regulation of the basolateral transporters of salivary acinar cells, we have measured cell volume and intracellular
pH (pHi) in perfused rat mandibular glands using proton NMR spectroscopy and BCECF fluorometry respectively. When perfusate Cl– was replaced by glucuronate, isethionate, methylsulphate, nitrate or thiocyanate, cell volume decreased slowly by about 15%
over a 10-min period. Replacement with bromide, which substitutes for Cl– on the Na+-K+-2Cl– cotransporter, caused only a small (4%) reduction in cell volume. Replacement of Cl– by glucuronate, isethionate or methylsulphate evoked a biphasic increase in pHi consisting of a rapid initial increase followed by a slower secondary rise whose time course was similar to that of cell
shrinkage. As judged by the effects of HCO3
– omission, 100 μM 4,4’-diisothiocyanatostilbene-2,2’-disulphonic acid (DIDS) and 1 mM amiloride, the initial rise in pHi was due to Cl–/HCO3
– exchange while the secondary rise resulted from activation of Na+/H+ exchange. Although replacement of Cl– by nitrate or thiocyanate also caused cell shrinkage, these substituting anions were less effective in activating the exchanger.
Therefore, while the upregulation of the exchanger following Cl– replacement may be due in part to cell shrinkage, there is also evidence for the involvement of an anion-sensitive regulatory
mechanism. This would be consistent with the hypothesis that both changes in cell volume and in intracellular Cl– concentration contribute to the up-regulation of the exchanger following muscarinic stimulation.
Received: 12 November 1996 / Received after revision: 11 August 1997 / Accepted: 18 August 1997 相似文献
20.
Glutathione is an essential metabolite required for resistance to oxidative stress in the yeastSaccharomyces cerevisiae 总被引:8,自引:0,他引:8
Glutathione (GSH) is an abundant cellular thiol which has been implicated in numerous cellular processes and in protection
against stress caused by xenobiotics, carcinogens and radiation. Our experiments address the requirement for GSH in yeast,
and its role in protection against oxidative stress. Mutants which are unable to synthesis GSH due to a gene disruption in
GSH 1, encoding the enzyme for the first step in the biosynthesis of GSH, require exogenous GSH for growth under non-stress conditions.
Growth can also be restored with reducing agents containing a sulphydryl group, including dithiothreitol, β-mercaptoethanol and cysteine, indicating that GSH is essential only as a reductant during normal cellular processes. In addition,
the GSH 1-disruption strain is sensitive to oxidative stress caused by H2O2 and tert-butyl hydroperoxide. The requirement for GSH in protection against oxidative stress is analogous to that in higher
eukaryotes, but unlike the situation in bacteria where it is dispensable for growth during both normal and oxidative stress
conditions.
Received: 20 September / 21 October 1995 相似文献