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101.
The effect of energy status on the response of luteinizing hormone (LH) pulse frequency to acute short-term energy deficiency created by fasting in estradiol-treated ovariectomized Shiba goats was studied in two experiments. In experiment 1, eight goats whose mean body weight (BW) was 25.6 +/- 5.8 (mean +/- S.D.)kg were fed 500 g hay cubes daily for 1 week. Then they were fasted for 3 days. Blood samples were collected for 4 h at 6 min intervals on the last day of feeding, first, second and third day of fasting for LH analysis. The goats were divided into light (<24 kg, n = 4) and heavy (> or =24 kg, n = 4) groups for data analysis. There was no difference in LH pulse frequency between the last day of feeding and each day of fasting in the heavy group. LH pulse frequency was significantly (P < 0.05) suppressed on the second day (3.3 +/- 1.3 pulses/4 h) and on the third day (2.3 +/- 1.9 pulses/4 h) relative to the day prior to fasting (4.8 +/- 1.5 pulses/4 h) in the light group. In experiment 2, BW plus a body mass index (gBMI: (body weight (kg)/withers height (m)/body length (m)) x 10) were measured to define energy status. Nine goats (BW, 25.6 +/- 5.8 kg) were fed 500 g hay cubes daily for a week and then fasted for 3 days. Then they were divided into two groups offered either a maintenance (n = 4) or a restricted (n = 5) level of feeding for 4 weeks. The restricted level of feeding was 30% of maintenance requirement based on the BW recorded weekly. The feeding level was then adjusted to maintain BW for a further week followed by 3 day fasting for restricted animals. Blood samples were collected for 6 h at 10 min intervals on the day prior to fasting and on third day of fasting before and after the dietary manipulation. BW (26.6 +/- 2.2 to 26.8 +/- 3.8 kg) and gBMI (8.4 +/- 0.4 to 7.8 +/- 0.3) remained constant over the period prior to fasting for the maintenance animals but were significantly lower (P < 0.05) after 4 weeks for the restricted goats (BW, 26.3 +/- 2.1 to 21.5 +/- 2.4 kg; gBMI, 8.4 +/- 0.9 to 6.9 +/- 0.7). There was no significant difference in the LH pulse frequency between feeding and fasting day in both sampling periods in the maintenance group. In the restricted group, LH pulse frequency was not suppressed by fasting in the first sampling period (6.8 +/- 2.9 to 5.2 +/- 2.5 pulses/6 h), whereas it tended to be suppressed (4.8 +/- 3.1 to 1.6 +/- 2.3 pulses/6 h; P < 0.06) and was significantly (P < 0.05) correlated to body weight (r = 0.70) and gBMI (r = 0.81) after the dietary manipulation. These results suggest that the suppressive effect of short-term energy restriction (fasting) on pulsatile LH secretion is related to body energy status. 相似文献
102.
Chemiluminescence associated with the oxidative metabolism of salicylic acid in rat liver microsomes
Doi H Iwasaki H Masubuchi Y Nishigaki R Horie T 《Chemico-biological interactions》2002,140(2):109-119
Rat liver microsomal suspension (1 mg protein per ml) was incubated at 37 degrees C with 5 mM salicylic acid and 0.2 mM NADPH. The amounts of thiobarbituric acid reactive substances (TBARS) and 2,5-dihydroxybenzoic acid (2,5-DHB), an oxidative metabolite of salicylic acid increased with the incubation time. Simultaneously spontaneous chemiluminescence (CL) was found to be generated there. The addition of SKF-525A, an inhibitor of cytochrome P450 (P450), to the reaction mixture inhibited the CL generation together with the inhibition of the oxidative metabolism. The anti-oxidants and singlet oxygen scavengers like N,N-diphenylphenylenediamine (DPPD) and histidine suppressed the CL generation. The addition of 1,4-diazabicyclo [2.2.2] octane (DABCO), a singlet oxygen quencher, to the reaction mixture generating CL enhanced CL transiently and then CL decreased markedly. Thus CL observed here may possibly originate from the singlet oxygen. The CL generation was suggested to be closely related with salicylic acid-induced lipid peroxidation, and to be coupled with the oxidative metabolism mediated by P450 in rat liver microsomes. 相似文献
103.
Causal relationship between the loss of RUNX3 expression and gastric cancer 总被引:137,自引:0,他引:137
Li QL Ito K Sakakura C Fukamachi H Inoue Ki Chi XZ Lee KY Nomura S Lee CW Han SB Kim HM Kim WJ Yamamoto H Yamashita N Yano T Ikeda T Itohara S Inazawa J Abe T Hagiwara A Yamagishi H Ooe A Kaneda A Sugimura T Ushijima T Bae SC Ito Y 《Cell》2002,109(1):113-124
Runx3/Pebp2alphaC null mouse gastric mucosa exhibits hyperplasias due to stimulated proliferation and suppressed apoptosis in epithelial cells, and the cells are resistant to growth-inhibitory and apoptosis-inducing action of TGF-beta, indicating that Runx3 is a major growth regulator of gastric epithelial cells. Between 45% and 60% of human gastric cancer cells do not significantly express RUNX3 due to hemizygous deletion and hypermethylation of the RUNX3 promoter region. Tumorigenicity of human gastric cancer cell lines in nude mice was inversely related to their level of RUNX3 expression, and a mutation (R122C) occurring within the conserved Runt domain abolished the tumor-suppressive effect of RUNX3, suggesting that a lack of RUNX3 function is causally related to the genesis and progression of human gastric cancer. 相似文献
104.
The ANGUSTIFOLIA gene of Arabidopsis, a plant CtBP gene, regulates leaf-cell expansion, the arrangement of cortical microtubules in leaf cells and expression of a gene involved in cell-wall formation
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Kim GT Shoda K Tsuge T Cho KH Uchimiya H Yokoyama R Nishitani K Tsukaya H 《The EMBO journal》2002,21(6):1267-1279
105.
106.
Sagane Y Watanabe T Kouguchi H Sunagawa H Obata S Oguma K Ohyama T 《Biochemical and biophysical research communications》2002,292(2):434-440
The nontoxic-nonhemagglutinin (NTNHA) component, in both isolated form and the neurotoxin (NT)/NTNHA complexed form, was prepared protease-free from toxin complexes produced by Clostridium botulinum type D strain 4947. NTNHA in both preparations was found to be spontaneously converted to the nicked NTNHA form leading to 15- and 115-kDa fragments with the excision of several amino acid residues at specific sites on SDS-PAGE during long-term incubation, while that of the NT/NTNHA/hemagglutinin complexed form remained unnicked single-chain polypeptides under the same conditions. Considering that the NTNHA preparation contained small amounts of the nicked form of NTNHA and the addition of trypsin accelerated the cleavage, it is speculated that a nicked form of NTNHA remaining after the purification and/or NTNHA itself catalyzes the cleavage of intact NTNHA. 相似文献
107.
Kashino Y Koike H Yoshio M Egashira H Ikeuchi M Pakrasi HB Satoh K 《Plant & cell physiology》2002,43(11):1366-1373
Using a recently introduced electrophoresis system [Kashino et al. (2001) Electrophoresis 22: 1004], components of low-molecular-mass polypeptides were analyzed in detail in photosystem II (PSII) complexes isolated from a thermophilic cyanobacterium, Thermosynechococcus vulcanus (formerly, Synechococcus vulcanus). PsbE, the large subunit polypeptide of cytochrome b(559), showed an apparent molecular mass much lower than the expected one. The unusually large mobility could be attributed to the large intrinsic net electronic charge. All other Coomassie-stained polypeptides were identified by N-terminal sequencing. In addition to the well-known cyanobacterial PSII polypeptides, such as PsbE, F, H, I, L, M, U, V and X, the presence of PsbY, PsbZ and Psb27 was also confirmed in the isolated PSII complexes. Furthermore, the whole amino acid sequence was determined for the polypeptide which was known as PsbN. The whole amino acid sequence revealed that this polypeptide was identical to PsbTc which has been found in higher plants and green algae. These results strongly suggest that PsbN is not a member of the PSII complex. It is also shown that cyanobacteria have cytochrome b(559) in the high potential form as in higher plants. 相似文献
108.
Tarui H Mori N Nishida R Okabe K Kuwahara Y 《Bioscience, biotechnology, and biochemistry》2002,66(1):135-140
A new monoterpene lactone from the acarid mite, Schwiebea araujoae, was elucidated without its isolation by GC/FT-IR and GC/MS analyses to be 3-(4-methyl-3-pentenyl)-2(5H)-furanone (1) and tentatively named as alpha,alpha-acariolide. The structure of 1 was identified by its synthesis from alpha-bromo-gamma-butyrolactone via 4 reaction steps. The synthesized compound gave the same GC/MS and GC/FT-IR spectra as those of the natural product. The other monoterpene lactone was likewise elucidated from the unidentified Rhizoglyphus mite to be 4-(4-methyl-3-pentenyl)-2(5H)-furanone (2) and named as alpha,beta-acariolide; it was also identified by its synthesis in 5 reaction steps from the same butyrolactone as the starting material. GC/MS and GC/FT-IR spectra of the preparation were identical to those of the natural product. 相似文献
109.
The spatial and temporal patterns of post-embryonal cell growth and cell division were characterised in excised cotyledons
of vegetable marrow (Cucurbita pepo L. var. giromontia Alef.) incubated in water. The concurrent roles of these two processes in cotyledon growth were determined using paradermal
sections of the first palisade layer of developing cotyledons. Tissue specificity was observed in the pattern of cell division.
The daughter cells derived from an initial cell, which had already differentiated before imbibition of the seeds, were tightly
packed in a cluster, which enabled us to monitor cell division during early cotyledon development. Heterogeneity of cell size
was recognised during the process of cell proliferation in the cluster, suggesting that cell division is uncoupled from control
of cell size. There was significantly more cell division in the marginal part of the cotyledons than in other parts, suggesting
high activity of the marginal meristem. Light enhanced cell and cotyledon enlargement, but had no effect on the number of
divisions. This study elucidated the cellular basis of post-germinative Cucurbita cotyledon morphogenesis and development.
Electronic Publication 相似文献
110.
Histochemical analysis of macrophage migration inhibitory factor in psoriasis vulgaris 总被引:1,自引:1,他引:0
Shimizu T Nishihira J Mizue Y Nakamura H Abe R Watanabe H Ishibashi T Shimizu H 《Histochemistry and cell biology》2002,118(3):251-257
Psoriasis is a persistent cutaneous disease characterized by skin inflammation and infiltration of immunocytes such as lymphocytes and monocytes/macrophages, concomitant with abnormal epidermal hyperproliferation. We previously showed that the serum level of macrophage migration inhibitory factor (MIF) and its production by peripheral blood mononuclear cells of patients with psoriasis were closely correlated with the severity of clinical symptoms; however, the precise role of MIF in psoriatic epidermis remains to be clarified. The current study was carried out to elucidate the possible involvement of MIF in psoriasis, using immunohistochemistry and in situ hybridization. In contrast to elevated serum MIF in psoriasis, MIF-positive staining in the lesional psoriatic epidermis was significantly decreased, as demonstrated by immunohistochemical analysis using an anti-MIF antibody. Consistent with this finding, we found, by in situ hybridization, that MIF mRNA concomitantly decreased in the psoriatic lesions. Although the reason for the different MIF levels in the psoriatic epidermis and in the circulation remains unknown, it is hypothesized that MIF, a potential growth factor, might be decreased in psoriatic lesions to counterregulate the abnormal epidermal proliferation caused by dysregulation of cytokines and growth factors. 相似文献