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101.
Previously it was demonstrated that Klebsiella pneumoniae O3 lipopolysaccharide (KO3 LPS) exhibited much stronger adjuvant action on antibody response to subcutaneously (s.c.) injected sheep red blood cells or deaggregated bovine serum albumin than did other kinds of LPS, the R-form LPS lacking the O-specific polysaccharide chain of KO3 LPS (R-LPS), and the lipid A fractionated from KO3 LPS. We compared histological changes in the regional subcutaneous tissues of mice injected subcutaneously (s.c.) with KO3 LPS, the lipid A, and R-LPS. At the early stage after injection, KO3 LPS induced the infiltration of a large number of inflammatory cells, mainly polymorphonuclear leukocytes (PMN), at the site of injection. Neither R-LPS nor the lipid A induced the accumulation of PMN so much as KO3 LPS did. When injected s.c. with LPS from Escherichia coli O111 (EO111 LPS) and O55 (EO55 LPS), and Salmonella enteritidis (Sent LPS), the appearance of PMN at the regional site was much less than KO3 LPS. KO3 LPS could accumulate more 51Cr-labeled leukocytes at the injection site than EO111 LPS and Sent LPS. Administration of acetylsalicylic acid, which can inhibit leukocyte migration in inflammatory lesions, suppressed its adjuvant action. It was therefore suggested that the strong adjuvant action of KO3 LPS in s.c. injection might be dependent on its potent capability of accumulating PMN at the regional subcutaneous tissue. Furthermore, at the late stage after injection, the formation of several lymphoid follicles at the regional site was seen only in mice injected with KO3 LPS. It might be also related to the strong adjuvant action of KO3 LPS. 相似文献
102.
Involvement of Ca2+ release and activation of phospholipase A2 in mitochondrial dysfunction during anoxia 总被引:1,自引:0,他引:1
During anoxic incubation, depletion of mitochondrial ATP was followed by release of Ca2+ with concomitant increase in the rate of state 4 respiration due to disruption of the diffusion barrier against protons. The external addition of ATP and its non-metabolizable analog, beta,gamma-methylene adenosine 5'-triphosphate, prevented both the release of Ca2+ and increase in the rate of state 4 respiration. Addition of EGTA, which did not prevent release of the ion, resulted in little increase in the respiration rate. Addition of an inhibitor of mitochondrial phospholipase A2, such as quinacrine, dibucaine, or chlorpromazine, also prevented increase in the respiration rate without affecting Ca2+ release from mitochondria during anoxic incubation. Non-esterified polyunsaturated fatty acids were also found to be liberated from anoxic mitochondria. External addition of the ATP-analog, EGTA, and inhibitors of phospholipase A2 suppressed the liberation of non-esterified polyunsaturated fatty acids. Melittin and Ca2+, which activate phospholipase A2, increased the rate of state 4 respiration and the liberation of fatty acids. These findings support the hypothesis proposed previously that the following sequence changes occurs in mitochondria during anoxia; depletion of ATP, liberation of free calcium from mitochondria, and disruption of the diffusion barrier against H+ of the inner membrane. The results also indicate another event; activation of phospholipase A2 by release Ca2+ which results in H+ leakiness of the inner membrane. 相似文献
103.
A Seko K Kitajima M Iwasaki S Inoue Y Inoue 《The Journal of biological chemistry》1989,264(27):15922-15929
New glycoproteins of 100-120 kDa were isolated from the unfertilized eggs of flounder, Paralichthys olivaceus. Compositionally indistinguishable glycopeptides of 6 kDa were also purified from the activated or fertilized eggs. These high and low molecular mass glycoproteins are characterized by high (about 85%) carbohydrate content. Although some heterogeneities exist in the amino acid sequences, the 6-kDa glycopeptides (decapeptides with single large N-linked glycan chains), isolated from the fertilized eggs are the repeating units of the high molecular mass glycoproteins. As judged from several distinctive features the 100-120-kDa glycoproteins are apparently major components of cortical alveoli of flounder eggs and are regarded as members of glycoproteins we have defined under the name of "hyosophorin" (Kitajima, K., Inoue, S., and Inoue, Y. (1989) Dev. Biol. 132, 544-553). Composition analysis, Smith degradation, hydrazinolysis-nitrous acid deamination, permethylation analysis, and 400-MHz 1H NMR spectroscopy provided evidence for the structure of a novel penta-antennary glycan chain attached to the repeating unit (decapeptide) of the protein core. The structure thus determined is: (Formula: see text). The presence of a unique class of carbohydrate-rich glycoproteins (H-hyosophorin) in the unfertilized eggs, their conversion to the repeating unit (L-hyosophorin) at fertilization, and the finding of a free glycan chain that was formed by scission between the GlcNAc and Asn residues of L-hyosophorin, in the fertilized eggs including embryos of 4-11-h postinsemination, support the view that these molecules may be important in fertilization and subsequent development. 相似文献
104.
105.
The murine Leydig tumor cell line, MLTC-1, contains a gonadotropin receptor-coupled adenylate cyclase. Although the binding of human choriogonadotropin (hCG) initially causes cells to accumulate cAMP, in time, the response to hCG is attenuated by desensitization. Treating intact cells with the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), or with diacylglycerol also causes desensitization of the hCG response. These compounds are activators of calcium/phospholipid-dependent protein kinase (PKC). Treating MLTC-1 cells with TPA or dioctanoylglycerol increased the portion of PKC in the cell membrane fraction. This phenomenon is associated with activation of PKC. Treating isolated membranes with purified PKC desensitize the hCG response. Thus, desensitization caused by TPA or dioctanoylglycerol is probably mediated by PKC. PKC is normally activated when phosphoinositides are metabolized to diacylglycerol and inositol phosphates. There was no significant accumulation of inositol phosphates when cells were treated with hCG. hCG did not increase the portion of PKC in the cell membrane fraction. However, hCG could desensitize isolated membranes, but TPA could not. We conclude that although protein kinase C activity can desensitize the gonadotropin response, hCG does not cause desensitization by activating PKC. The implications of this observation are discussed. 相似文献
106.
S Sumi K Inoue R Hosotani M Kogire R Doi M Yun S Higashide H Minote K Takaori H Kaji 《Life sciences》1990,47(13):1115-1119
The effect of intravenous administration of human epidermal growth factor on the splanchnic blood flows was examined in anesthetized dogs, using an ultrasonic transit-time volume flow meter. Human epidermal growth factor (0.1, 0.5 and 1 microgram/kg) significantly increased blood flows in the portal vein (36.9 +/- 7.4% at 1 microgram/kg) and the superior mesenteric artery (49.0 +/- 16.8% at 1 microgram/kg). Systemic blood pressure monitored simultaneously was significantly decreased (8.4 +/- 1.2% at 1 microgram/kg). This study is the first to demonstrate that intravenous administration of epidermal growth factor increases the portal venous blood flow. 相似文献
107.
108.
An adenosine-assimilating bacterium, Klebsiella sp. strain LF1202, inducibly formed a novel nucleoside phosphorylase which acted on both purine and pyrimidine nucleosides when the cells were cultured in medium containing adenosine as a sole source of carbon and nitrogen. The enzyme was purified (approximately 83-fold, with a 17% activity yield) to the homogeneous state by polyacrylamide gel electrophoresis. The molecular weight of the purified enzyme was calculated to be 125,000 by gel filtration of Sephadex G-200 column chromatography, although the enzyme migrated as a single protein band with a molecular weight of 25,000 on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis; thus, it was thought to consist of five identical subunits. Besides purine nucleosides (adenosine, inosine, and guanosine), the purified enzyme also acted on pyrimidine nucleosides such as uridine, 2'-deoxyuridine, and thymidine. The purified enzyme catalyzed the synthesis of adenine arabinoside, a selective antiviral pharmaceutic agent, from uridine arabinoside and adenine. 相似文献
109.
T Fujii K Kondo F Shimizu H Sone J Tanaka T Inoue 《Applied and environmental microbiology》1990,56(4):997-1003
An integration plasmid, pIARL28, containing the ribosomal DNA gene as a homologous recombination sequence was constructed for introduction of the alpha-acetolactate decarboxylase gene into brewer's yeast. The transformation efficiency of pIARL28 was 20- to 50-fold higher than those of the other YIp vectors, as yeast cells had approximately 140 copies of the ribosomal DNA gene. All transformants showed very high alpha-acetolactate decarboxylase activity due to the multiple integrated copies of the plasmid. The transformants were grown in nonselective conditions, and segregants which had maintained the alpha-acetolactate decarboxylase expression cassette but no other vector sequences were isolated. Southern analysis showed that these marker-excised segregants contained more than 20 copies of the alpha-acetolactate decarboxylase gene and were stably maintained under nonselective conditions. Fermentation tests confirmed that the diacetyl concentration was considerably reduced in wort fermented by these marker-excised segregants. The degree of reduction was related to the copy number of the alpha-acetolactate decarboxylase gene. 相似文献
110.
S Kasahara S Nishikawa H Ishida T Nagata N Yamauchi K Ohishi Y Wakano H Inoue 《Biochemical and biophysical research communications》1992,182(2):817-823
The role of 5'-methylthioadenosine (MTA), formed during the process of polyamine biosynthesis, on differentiation of osteoprogenitor cells was assessed by its effects on alkaline phosphatase (ALP) activity, bone nodule formation and osteopontin contents of cultured rat calvaria (RC) cells. These three markers were stimulated by exogenous MTA and were depressed by 5'-difluoromethylthioadenosine (DFMTA), a synthetic inhibitor of MTA phosphorylase, which cleaves MTA to adenine and 5-methylthioribose-1-phosphate. 5-Methylthioribose and 2-keto-4-methylthiobutyrate, metabolites of 5-methylthioribose-1-phosphate, had no effects on ALP activity and bone nodule formation in the presence or absence of DFMTA. On the other hand, adenine enhanced ALP activity, bone nodule formation and osteopontin contents in mineralized nodules and also partially reversed DFMTA-induced inhibition of these three markers. MTA, its metabolites and DFMTA did not affect the growth of RC cells under these culture conditions. These results suggest that adenine formed from MTA is important in the differentiation of RC cells. 相似文献