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1.
Various sex hormones (testosterone, oestradiol, dehydroepiandrosterone), in the form of suspensions in oil, are injected into the allantois of normal and chondrodystrophic (Creeper) chick embryos of 6 days 1/2 incubation. Observations made on each of the phenotypes on the 12th day of incubation show that oil injected alone causes a significant decrease in the dry weight of the tibiae. This inhibitory effect is partially abolished when the oil is injected together with the sex hormones, testosterone being the most effective.  相似文献   

2.
Physical exercise induces cell proliferation in the adult hippocampus in rodents. Serotonin (5-HT) and angiotensin (Ang) II are important mediators of the pro-mitotic effect of physical activity. Here, we examine precursor cells in the adult brain of mice lacking angiotensin-converting enzyme (ACE) 2, and explore the effect of an acute running stimulus on neurogenesis. ACE2 metabolizes Ang II to Ang-(1–7) and is essential for the intestinal uptake of tryptophan (Trp), the 5-HT precursor. In ACE2-deficient mice, we observed a decrease in brain 5-HT levels and no increase in the number of BrdU-positive cells following exercise. Targeting the Ang II/AT1 axis by blocking the receptor, or experimentally increasing Trp/5-HT levels in the brain of ACE2-deficient mice, did not rescue the running-induced effect. Furthermore, mice lacking the Ang-(1–7) receptor, Mas, presented a normal neurogenic response to exercise. Our results identify ACE2 as a novel factor required for exercise-dependent modulation of adult neurogenesis and essential for 5-HT metabolism.  相似文献   

3.
During pseudopregnancy in the Rabbit the DNA synthesis in the uterine epithelium is very reduced. These results conjoined with the decrease of the mitotic index and previous ultrastructural observations allow to think that multinucleated cells proceed mainly by cell fusion.  相似文献   

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目的 观察依那普利(Ena)对高糖诱导的大鼠肾小球系膜细胞(GMCs)增殖及分泌转化生长因子-β1(TGF-β1)和层粘连蛋白(LN)的影响.方法 大鼠GMCs分别培养于正常浓度葡萄糖(NG,5.5mmol/L)、高浓度葡萄糖(HG,20mmol/L)及高糖和不同浓度(10-7mol/L、10-6mol/L、10-5mol/L)的Ena中,同时设空白对照.分别采用四甲基偶氮唑蓝(MTT)法和酶联免疫吸附试验(ELISA)、放射免疫法(RIA)检测不同时间(24 h、48 h、72 h)GMCs增殖情况和细胞培养上清液中TGF-β1、LN的含量.结果 与空白对照组比较,正常糖组和高糖组GMCs增殖增加,TGF-β1、LN分泌增多(P〈0.001),高糖组更明显(P〈0.001).与高糖组比较,高、中、低浓度的Ena干预均可逆转上述变化.且在一定浓度范围内,Ena无明显细胞毒性.结论 高糖可致GMCs增殖和TGF-β1、LN分泌增多,Ena可抑制高糖诱导的GMCs增殖与分泌TGF-β1、LN,这可能是其减少细胞外基质(ECM)积聚的机理之一,并有利于延缓糖尿病肾病肾小球硬化(GS)的进展.  相似文献   

6.
This paper describes the induction of uterine eosinophilia as well as of deep endometrial edema and increase of uterine wet weight in the immature rat by the catecholestrogens 2-OH-estradiol and 4-OH-estradiol. These effects are thought to be mediated by eosinophils via a specific eosinophil receptor system. 4-OH-estradiol was equipotent with estradiol, whereas the effect of 2-OH-estradiol was significantly weaker.  相似文献   

7.
An integrated histological and ultrastructural study of the endometrial microcirculation in rats reveals that lymphatic capillaries are absent from the superficial uterine mucosa. Blood capillaries are fenestrated, and their basement membrane may be poorly developed.  相似文献   

8.
Summary An integrated histological and ultrastructural study of the endometrial microcirculation in rats reveals that lymphatic capillaries are absent from the superficial uterine mucosa. Blood capillaries are fenestrated, and their basement membrane may be poorly developed.Supported by a grant from the Nationaal Fonds voor Wetenschappelijk Onderzoek-Fonds voor Geneeskundig Wetenschappelijk Onderzoek (Belgium).  相似文献   

9.
The 3H-oestradiol receptor complex obtained from the cytosol fraction of foetal guinea-pig uterus was purified by the following steps: column chromatography in Sephadex G-15 and Ultrogel, and by electrofocusing on polyacrylamide plates. In the final step a concentration of 15-17% of the foetal uterine oestradiol receptor protein was obtained. The isoelectric point (pl) of this receptor was determined to be 6.1-6.2.  相似文献   

10.
Summary This paper describes the induction of uterine eosinophilia as well as of deep endometrial edema and increase of uterine wet weight in the immature rat by the catecholestrogens 2-OH-estradiol and 4-OH-estradiol. These effects are thought to be mediated by eosinophils via a specific eosinophil receptor system. 4-OH-estradiol was equipotent with estradiol, whereas the effect of 2-OH-estradiol was significantly weaker.Acknowledgments. This work was supported by Grant B-1493-8435 from the University of Chile. We are indebted to Prof. R. Knuppen, Lübeck, for providing the CE.  相似文献   

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Rapidly renewing epithelial tissues such as the intestinal epithelium require precise tuning of intercellular adhesion and proliferation to preserve barrier integrity. Here, we provide evidence that desmoglein 2 (Dsg2), an adhesion molecule of desmosomes, controls cell adhesion and proliferation via epidermal growth factor receptor (EGFR) signaling. Dsg2 is required for EGFR localization at intercellular junctions as well as for Src-mediated EGFR activation. Src binds to EGFR and is required for localization of EGFR and Dsg2 to cell–cell contacts. EGFR is critical for cell adhesion and barrier recovery. In line with this, Dsg2-deficient enterocytes display impaired barrier properties and increased cell proliferation. Mechanistically, Dsg2 directly interacts with EGFR and undergoes heterotypic-binding events on the surface of living enterocytes via its extracellular domain as revealed by atomic force microscopy. Thus, our study reveals a new mechanism by which Dsg2 via Src shapes EGFR function towards cell adhesion.  相似文献   

13.
C S Potten  J C Bullock 《Experientia》1983,39(10):1125-1129
The changes in the labeling index (LI) with time after a single injection of tritiated thymidine (3HTdR) at each of 4 different times of the day have been studied. Slight differences occur in the shape of these LI curves, (e.g. in the timing of the peaks) depending on the time of day when the initial injection was given. Thus, the time of day influences not only the number of cells in DNA synthesis but also determines the subsequent behavior of the labeled cells. The curves show 3 distinct peaks from which estimates of the cell cycle time can be made. The technique permits the cell cycle time to be estimated. From the data as a whole a minimum cell cycle time of 90 h for basal cells in the epidermis on the back of a mouse is obtained. The technique also provides estimates for the duration of S + G2 + M which varies depending on the time of day that the label is given. The LI curves can best be understood if the basal layer is assumed to contain 2 cell populations with differing cell cycle times; one having a long cell cycle (about 180 h) but short S-phase and containing the stem cells, the other having a short cell cycle (about 90 h) and a long S-phase duration and consisting of transit cells.  相似文献   

14.
Perchloric acid-soluble protein (PSP) may play an important role in the regulation of cellular physiological functions because it has been highly conserved throughout evolution; however, this role has not been well elucidated. In previous reports, we suggested that PSP regulates cell proliferation. In this study, we examined the effect of PSP expression on proliferation of the normal rat kidney cell line NRK-52E, the rat hepatocyte cell line RLN-10, and the rat hepatoma cell line dRLh-84. Cells transfected with pcDNA-sense-PSP (pcDNA-S-PSP) over-expressed PSP mRNA and protein, and cell proliferation of the transfected cells was suppressed compared with that of cells transfected with pcDNA-empty (pcDNA-E). Cell viability of pcDNA-S-PSP-transfected cells was similar to that of pcDNA-E-transfected cells. Thus, over-expression of PSP suppresses cell proliferation without any influence on cell viability. These findings are the first to report an inhibitory activity of PSP on cell proliferation. Received 27 April 2001; received after revision 8 June 2001; accepted 8 June 2001  相似文献   

15.
To determine if intestinal stromal cells secrete diffusible factors such as insulin-like growth factors (IGFs) capable of regulating epithelial cell growth in vitro, stromal cells were isolated by enzymatic digestion of rat intestine. Incorporation of [3H]thymidine into DNA and [14C]leucine into protein of IEC-6 cells, a model intestinal epithelial cell line, was significantly increased (two- to threefold) when the IEC-6 cells were co-cultured with stromal cells, relative to IEC-6 cells grown alone. Medium conditioned by stromal cells stimulated DNA synthesis of IEC-6 cells in a dose-dependent manner. Analysis of the conditioned medium revealed that intestinal stromal cells secreted IGF-I, but little IGF-II, in addition to an M r 32,000 IGF-binding protein (IGFBP-2) and an IGFBP having M r∼ 24,000. We conclude that rat intestinal stromal cells secrete one or more diffusible factors, which may include IGF-I and IGFBPs, capable of stimulating proliferation of IEC-6 cells in vitro. Received 25 August 1997; received after revision 7 November 1997; accepted 20 November 1997  相似文献   

16.
There is an immense load of non-pathogenic commensal bacteria in the distal small intestine and the colon of mammals. The physical barrier that prevents penetration (translocation) of these organisms into the body is a simple epithelium comprised of the single enterocyte/colonocyte cell layer with its overlying mucus. In this review, we discuss the roles of intestinal T cells in initiating and regulating innate and adaptive mucosal immune responses of the mucosal immune system that avoid or limit penetration of the commensal intestinal bacteria. Received 9 August 2002; accepted 9 September 2002 RID="*" ID="*"Corresponding author.  相似文献   

17.
The measurement of the binding of steroid hormone receptors to biospecific adsorbants requires the development of "exchange" techniques. Two types of techniques based on the principle of differential dissociation were standardized: solid phase exchange with hydroxylapatite and liquid phase exchange with adsorption of the ligand to charcoal dextran. In both cases, binding of oestradiol to its receptor was measured in calf uterine cytosol extracts. Results obtained by both techniques were comparable. The half-times of the oestradiol-receptor complex dissociation determined from exchange kinetics are on the same order as those obtained by direct methods used in previous studies.  相似文献   

18.
Summary The3H-oestradiol receptor complex obtained from the cytosol fraction of foetal guinea-pig uterus was purified by the following steps: column chromatography in Sephadex G-15 and Ultrogel, and by electrofocusing on polyacrylamide plates. In the final step a concentration of 15–17% of the foetal uterine oestradiol receptor protein was obtained. The isoelectric point (pl) of this receptor was determined to be 6.1–6.2.The expenses of the investigation were partially defrayed by a grant from the Centre National de la Recherche Scientifique (CNRS), France (Equipe de Recherche CNRS No. 187).  相似文献   

19.
DNA aneuploidy has been identified as a prognostic factor in the majority of epithelial malignancies. We aimed at identifying ploidy-associated protein expression in endometrial cancer of different prognostic subgroups. Comparison of gel electrophoresis-based protein expression patterns between normal endometrium (n?=?5), diploid (n?=?7), and aneuploid (n?=?7) endometrial carcinoma detected 121 ploidy-associated protein forms, 42 differentially expressed between normal endometrium and diploid endometrioid carcinomas, 37 between diploid and aneuploid endometrioid carcinomas, and 41 between diploid endometrioid and aneuploid uterine papillary serous cancer. Proteins were identified by mass spectrometry and evaluated by Ingenuity Pathway Analysis. Targets were confirmed by liquid chromatography/mass spectrometry. Mass spectrometry identified 41 distinct polypeptides and pathway analysis resulted in high-ranked networks with vimentin and Nf-κB as central nodes. These results identify ploidy-associated protein expression differences that overrule histopathology-associated expression differences and emphasize particular protein networks in genomic stability of endometrial cancer.  相似文献   

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