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31.
K Higuchi A Ogo T Maki M Haji R Takayanagi M Ohashi H Nawata K Kato H Ibayashi 《Endocrinologia japonica》1989,36(6):881-885
The steroid, 19-hydroxyandrost-4-ene-3, 17-dione (19-hydroxyandrostene-dione, 19-OH-A-dione) has been known to enhance the mineralocorticoid action of aldosterone. To investigate the age-related change in the plasma 19-OH-A-dione concentration, plasma 19-OH-A-dione, androst-4-ene-3, 17-dione (A-dione), aldosterone and cortisol of 38 non-hypertensive healthy subjects (18 young men and 20 aged men) measured by specific radioimmunoassays. The basal plasma 19-OH-A-dione and A-dione concentration in aged men was significantly lower than in young men (P less than 0.01). Moreover, there was found to be a positive correlation between plasma 19-OH-A-dione and A-dione (P less than 0.01). On the other hand, plasma aldosterone and cortisol in aged men showed a tendency to decrease, but no statistical significance compared to young men was observed. This study demonstrated that there was an apparent age-related decrease not only in plasma A-dione, but also in plasma 19-OH-A-dione, an amplifier or aldosterone action. 相似文献
32.
Calyculin A and okadaic acid: inhibitors of protein phosphatase activity 总被引:44,自引:0,他引:44
H Ishihara B L Martin D L Brautigan H Karaki H Ozaki Y Kato N Fusetani S Watabe K Hashimoto D Uemura 《Biochemical and biophysical research communications》1989,159(3):871-877
Calyculin A and okadaic acid induce contraction in smooth muscle fibers. Okadaic acid is an inhibitor of phosphatase activity and the aims of this study were to determine if calyculin A also inhibits phosphatase and to screen effects of both compounds on various phosphatases. Neither compound inhibited acid or alkaline phosphatases, nor the phosphotyrosine protein phosphatase. Both compounds were potent inhibitors of the catalytic subunit of type-2A phosphatase, with IC50 values of 0.5 to 1 nM. With the catalytic subunit of protein phosphatase type-1, calyculin A was a more effective inhibitor than okadaic acid, IC50 values for calyculin A were about 2 nM and for okadaic acid between 60 and 500 nM. The endogenous phosphatase of smooth muscle myosin B was inhibited by both compounds with IC50 values of 0.3 to 0.7 nM and 15 to 70 nM, for calyculin A and okadaic acid, respectively. The partially purified catalytic subunit from myosin B had IC50 values of 0.7 and 200 nM for calyculin A and okadaic acid, respectively. The pattern of inhibition for the phosphatase in myosin B therefore is similar to that of the type-1 enzyme. 相似文献
33.
Quantitation and immunohistochemical localization of cathepsins E and D in rat tissues and blood cells 总被引:2,自引:0,他引:2
The distribution of cathepsins E and D in various rat tissues and blood cells was determined by immunoprecipitation and by immunohistochemistry with discriminative antibodies specific for each enzyme. While cathepsin D was detected in all of the tissues and blood cells tested (except for erythrocytes), cathepsin E had a relatively limited distribution. The cathepsin E content was highest in the stomach and was succeeded in the following order by the urinary bladder, thymus, spleen, cervical lymph node and bone marrow. Significant amounts of cathepsin E were also found in the colon, rectum, jejunum, skin, lung, kidney and submandibular gland. The other tissues tested had little or no detectable cathepsin E content. Of the blood cells tested, lymphocytes and peritoneal neutrophils contained high levels of cathepsin E. Erythrocytes had cathepsin E only as aspartic proteinases. When the subcellular localization of cathepsin E in the neutrophils was investigated by fractionation of the postnuclear supernatants, the enzyme behaved as a soluble cytosolic enzyme. In contrast, cathepsin D was mainly associated with the granular fraction. The immunohistochemical localization of cathepsins E and D was clearly different in the stomach, large intestines, kidney and urinary bladder, but was similar in the lymph node and spleen. The tissue-fixed macrophages, which were notable in the skeletal and cardiac muscle tissues, submucosal layers of the gastrointestinal tracts, salivary gland, lung and trachea, also exhibited similar intense immunoreactivities demonstrative of both cathepsins E and D. 相似文献
34.
M Kato H Nakayama Z Makita S Aoki Y Kuroda K Misawa H Yoshida K Yanagisawa S Nakagawa 《Hormones et métabolisme》1989,21(5):245-248
We have developed a radioimmunoassay (RIA) for nonenzymatically glycated serum proteins. The polyclonal antibodies prepared against reduced glycated human albumin were specific for the glucitollysine residues of serum proteins. Serum proteins from diabetic patients (n = 25) contained 5.3 +/- 2.8 nmoles of glucitollysine/mg protein, compared to 2.0 +/- 0.2 in controls (n = 20). The intra- and inter-assay variables were 3.2-6.2% and 4.4-8.6%, respectively. Results from this assay procedure correlated well with those from the boronate affinity chromatography procedure (r = 0.94; P less than 0.001). The data suggested that diabetic serum proteins contained at least 2.5 times as much immunochemically detectable glucitollysine residures as normal serum proteins after reduction of the proteins with sodium borohydride. 相似文献
35.
Carboxyl-terminal deletion analysis of the Streptococcus mutans glucosyltransferase-I enzyme 总被引:9,自引:0,他引:9
Sequential deletion of the carboxyl-terminal amino acids (including the six direct repeating units) of the glucosyltransferase-I (GTF-I) enzyme of Streptococcus mutans revealed differential effects on sucrase and GTF activities. Removal of all but one repeating unit resulted in a truncated enzyme with significant sucrase activity but no detectable GTF activity. These results are compatible with the presence of two functional domains in the enzyme. 相似文献
36.
The polymerase chain reaction for Mycoplasma pulmonis 总被引:2,自引:0,他引:2
R Harasawa K Koshimizu T Uemori O Takeda K Asada I Kato 《Microbiology and immunology》1990,34(4):393-395
In vitro DNA amplification by polymerase chain reaction was examined to detect Mycoplasma pulmonis. A pair of synthetic oligonucleotide primers was constructed, and used to amplify a unique sequence of M. pulmonis DNA. Amplified products were detected by agarose gel electrophoresis and verified by blot hybridization with a synthetic oligonucleotide probe. This system detected cellular DNA of M. pulmonis but not M. arthritidis or M. neurolyticum, and thus appears to be useful for M. pulmonis diagnosis. 相似文献
37.
K Yamashita A Umemoto S Grivas S Kato S Sato T Sugimura 《Nucleic acids symposium series》1988,(19):111-114
DNA adducts formed by 12 heterocyclic amines were analyzed by 32P-postlabeling method. Several DNA adducts were detected in rat liver by administration of each heterocyclic amine. Total adduct levels ranged from 0.5 for 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) to more than 250 for 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) per 10(7) nucleotides 24 hr after intragastric administration of these compounds. The N-hydroxy derivative of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was reactive toward DNA in vitro to form adducts. Addition of acetic anhydride to N-OH-MeIQx greatly enhanced its reactivity to DNA. 32P-Postlabeling analysis revealed that the MeIQx-DNA adducts formed in vivo and in vitro were identical. Thus, MeIQx would be metabolized in vivo to N-hydroxy form and further esterified to produce more reactive species, such as N-acetoxy form, which modify DNA to form adducts. 相似文献
38.
The heterogeneity of rat kidney lysosomes revealed by immunoelectron microscopic staining for cathepsins B and H 总被引:1,自引:0,他引:1
The heterogeneity of lysosomes was studied by analyzing the immunostaining behavior of cathepsins B and H in rat kidney proximal tubule cells. Rat kidneys were fixed by perfusion and embedded in Lowicryl K4M. A protein A-gold technique was applied to serial sections and a double labeling technique to conventional sections. By analyzing the immunostaining behavior of cathepsins B and H in the same lysosomes which were cut into separate sections, four types of lysosomes were found: Type 1 positive for both proteinases; type 2 strongly positive for cathepsin B, but weakly or negative for cathepsin H; type 3 strongly positive for cathepsin H, but weakly or negative for cathepsin B; and type 4 negative for both proteinases. The double labeling by two different sizes of the protein A-gold probes showed these four types of lysosomes. The results indicate that there exists the lysosomal heterogeneity of the proteinase content in the kidney proximal tubule cells. 相似文献
39.
Nobuo Kato Sumiko Mizuno Yukio Imada Masayuki Shimao Chikahiro Sakazawa 《Applied microbiology and biotechnology》1988,27(5-6):567-571
Summary Formaldehyde dismutase was greatly stabilized by immobilization in a urethane prepolymer (PU-6). The immobilized enzyme exhibited stochiometrical dismutation of formaldehyde to methanol and formate in several repeated reactions. Conversion of methanol to formate occurred in a reaction with an immobilized enzyme system consisting of alcohol oxidase, catalase and formaldehyde dismutase, and with an intact cell-mixture of Hansenula polymorpha and Pseudomonas putida. Furthermore, the stability of the cell-mixture during repeated reactions was greatly improved by the immobilization, the 600 mM methanol added periodically being converted to formate in a 75% yield in 12 h. The immobilized cellsystem was also effective for the conversion of several aliphatic alcohols, C1 to C4, to the corresponding acids. 相似文献
40.
Sachiko Aono Hiroshi Sato Reiji Semba Shigeo Kashiwamata Kanefusa Kato † Lawrence F. Eng† 《Journal of neurochemistry》1988,50(3):717-721
The behavior of marker proteins of glial cells [alpha-enolase, beta-S100 protein, and glial fibrillary acidic protein (GFAP)] was investigated quantitatively by using enzyme immunoassay systems during the development of cerebellar hypoplasia in jaundiced Gunn rats. A neuronal marker protein, gamma-enolase, was also measured as a reference. At postnatal day 8 corresponding to the early stage of cerebellar damage, the amount of beta-S100 on a protein basis was significantly higher in jaundiced homozygotes (jj) than in control nonjaundiced heterozygotes (j+), whereas no differences in alpha- and gamma-enolases and GFAP were observed between the two groups of rats. At days 15 and 30, which correspond, respectively, to the advanced and late stages of cerebellar damage, the three glial proteins, especially GFAP, were higher and the neuronal protein was lower in the jj rat cerebellum than in the control. These results are consistent with the reported histological observations that neuronal cells are vulnerable and damaged by bilirubin, whereas glial cells seem to be less sensitive. On the other hand, the amounts of beta-S100 and alpha-enolase per cerebellum were significantly lower in jj rats at days 15 and 30, as in the case of gamma-enolase, whereas that of GFAP remained at the same level as the control at day 15 and showed a slight but significant decrease at day 30. The possibility is suggested that beta-S100 and GFAP may be available as biochemical indicators of glial cells, especially in the early and advanced stages of cerebellar damage, respectively, but that alpha-enolase is less available. 相似文献