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11.
S Masumura M Hashimoto Y Hashimoto T Sato I Kihara Y Watanabe 《European journal of applied physiology and occupational physiology》1982,48(2):157-161
Activities of glycolytic enzymes in the aorta were investigated in female Wistar rats. There were two groups of rats; one served as the control (sedentary rats), while the other group was forced to run on a treadmill for 10 weeks. In the control animals, the activities of hexokinase, phosphofructokinase and aldolase were relatively lower than those of the other glycolytic enzymes (phosphoglucose isomerase, lactate dehydrogenase and pyruvate kinase). After exercise, the activity of phosphofructokinase increased by 15%, whereas the other enzymatic activities were much the same as in the controls. Within the limits of the experiments, the increased percentage of phosphofructokinase was statistically significant (p less than 0.05). Since phosphofructokinase is a putative rate limiting enzyme, this enzymatic activation may indicate that glycolytic activity in the rat aorta is enhanced during and after running exercise. 相似文献
12.
The effects of estrogen on the uridine uptake into cells were examined in primary cultures of liver parenchymal cells from Xenopus laevis. The total uptake of [3H]uridine into the estrogen-treated cells and its incorporation into RNA were about 1.5 times higher than the values for control cells. The uptake of [3H]adenosine and its incorporation into RNA were not affected by estrogen. An experiment in which liver parenchymal cells were double labeled with [3H]uridine and [3H]adenosine showed that estrogen elevated the specific radioactivity of the UTP pool 1.4-fold the value found for the control cells, but that of the ATP pool was not altered by estrogen. Short term labeling revealed that estrogen did not significantly alter the rate of the initial uptake of [3H]uridine into the cells, but it did stimulate [3H]uridine phosphorylation about 1.7-fold. Uridine kinase activity measured in cell-free extracts of hepatocytes treated with estrogen had a value 1.6 times that of the control cells. These data indicate that the stimulation of [3H]uridine uptake and phosphorylation in Xenopus laevis hepatocytes in the presence of estrogen is caused by the enhancement of uridine kinase activity. 相似文献
13.
Masanori Shinzato Mikihiro Shamoto Satoru Hosokawa Chiyuki Kaneko Akido Osada Miyuki Shimizu Asako Yoshida 《Biotechnic & histochemistry》1995,70(3):114-118
The present study shows that Langerhans cells can be differentiated from Interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells. 相似文献
14.
Stimulation of death receptors (Fas on human T-cell leukemia Jurkat cells and tumor necrosis factor receptor-1 on human monoblastic leukemia U937 cells) triggers the specific degradation of 28S ribosomal RNA, and this process may contribute to cell death through the inhibition of protein synthesis. We have developed an analytical method using a polyacrylamide-agarose composite gel to evaluate ribosomal subunits in apoptotic cells (human breast carcinoma MCF-7 cells treated with staurosporine and human 293T cells irradiated with ultraviolet light were used in addition to the two apoptosis systems described above). No alterations were detected by this method, suggesting that apoptosis, including the process of ribosomal RNA degradation, does not cause fragmentation or extensive conformational changes in the ribosome. We also examined the status of 21 different ribosomal proteins in apoptotic cells by immunoblotting with polyclonal antibodies. S11 was specifically downregulated in apoptotic MCF-7 cells and in other apoptotic breast carcinoma cells. Previous studies have shown that S11 is heterogeneously expressed in cancer cells. Taken together, it appears that particular intracellular environments regulate the expression of S11 protein. However, the mechanism by which this process is modulated is as yet unknown. Furthermore, we have demonstrated that our composite gel electrophoresis system can efficiently detect ubiquitination of ribosomal subunits. 相似文献
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Murine monoclonal antibodies to the myelin-associated glycoprotein (MAG) recognize Leu-7-reactive molecules on human mononuclear cells 总被引:2,自引:0,他引:2
M Arai M Nishizawa T Inuzuka M Tanaka H Baba S Sato T Miyatake 《Journal of immunology (Baltimore, Md. : 1950)》1987,138(10):3259-3263
It is known that the antibody to human myelin-associated glycoprotein (MAG) reacts with a subset of human mononuclear cells (MNC) mediating a natural killer (NK) activity. The properties of the target molecule of the anti-MAG antibody, however, have not yet been elucidated. Three (GC-J4, MC-P2, and MC-P4) of five murine monoclonal antibodies (mAb) to MAG bound to human MNC. Moreover, MC-P2 and MC-P4 inhibited the binding of 125I-labeled anti-Leu-7 to MNC in a dose-dependent fashion. Conversely, anti-Leu-7 inhibited the binding of MC-P2 and MC-P4 to MNC, but did not inhibit the binding of GC-J4. Therefore, it is possible that MC-P2 and MC-P4 bind directly to or close to the Leu-7 epitope, and that GC-J4 binds to the epitope which is distinct from the Leu-7 epitope. The electrophoretic patterns of immunoprecipitates with GC-J4, MC-P2 and anti-Leu-7 from detergent lysates of surface-labeled human MNC were very similar. The target molecules of anti-Leu-7 and anti-MAG mAb have apparent m.w. of 205, 170, 150, 135, 110, 85, 65, and 55 kDa. All of the molecules precipitated by these mAb are monomeric or noncovalently associated proteins, because the electrophoretic mobilities of the proteins remained unchanged whether the samples were reduced or not. MC-P4 may have a higher affinity for the 65 kDa molecule than the other mAb, and precipitates the 58 kDa molecule as well. Therefore, the fine antigenic specificity of MC-P4 is slightly different from those of anti-Leu-7 or MC-P2. The implication of these results is that mAb, whose specificity is directed to the carbohydrate part of human MAG, reacts with the Leu-7 reactive molecules on human MNC, and that at least two epitopes detected by anti-MAG mAb coexist on the surface molecules with various apparent m.w. 相似文献
18.
19.
A new fluorogenic acceptor for sialyltransferase, 2-[(2-pyridyl)amino]ethyl O-beta-D-galactopyranosyl-(1----4)-beta-D-glucopyranoside, was prepared from lactose as a starting material. Sialyltransferase activity was assayed by incubation of the enzyme with the acceptor and CMP-N-acetylneuraminic acid, separation of the fluorogenic sialylated product from the enzymatic reaction mixture by HPLC, and measurement of the product. Compared to assays so far reported that use radioactive substrates, this assay is simple and rapid. This method was used to assay sialyltransferase activity in human serum. 相似文献
20.
The binding nature of mibolerone in cytosols and nuclear extracts from hypertrophic human prostate was examined in comparison with that of R 1881. The binding of mibolerone in the cytosol and nuclear extract was single and of high affinity when evaluated by the method of Scatchard (1949). Binding of mibolerone with testosterone-binding globulin was not detected. The sedimentation coefficients of the binder for mibolerone in the cytosol and nuclear extract were 10.6 S and 3.6 S, respectively. When triamcinolone acetonide was induced in the binding medium, inhibition of mibolerone binding in the cytosol by testosterone and dihydrotestosterone was potentiated and this may imply that the binding observed in the presence of triamcinolone acetonide was responsible for the binding of the androgen receptor. In the nuclear extract, the binding was attributable mainly to the androgen receptor irrespective of the presence or absence of triamcinolone acetonide. These properties of the binding observed in the hypertrophic human prostate were almost same as those of the binding with R 1881. Although maximum binding sites measured using mibolerone were correlated with those using R 1881 in the cytosols as well as in the nuclear extracts, the values obtained with mibolerone were slightly greater than those with R 1881. Thus, mibolerone seems to be a suitable ligand for measuring the androgen receptor, but when compared with R 1881 no special merits in using mibolerone were detected. 相似文献