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31.
Tryptophan as a circulating precursor of serotonin (5-HT) may suppress food intake and body weight. Tryptophan administration can enhance the generation of reactive oxygen species (ROS) by inducing oxidative pathway in vivo and in vitro. We have examined the effect of repeated tryptophan administration on food consumption, body weight, brain lipid peroxidation and 5-HT immunoreactivity. Tryptophan was given at the dose of 100 mg/kg/24 hr in 0.2 ml saline solution i.p. for 7 days to mice. Control mice received 0.9% NaCL solution at the same manner and volume. Body weights were recorded at the beginning and end of the experiments. Thiobarbituric acid reactive substance (TBARS), the last product of lipid peroxidation, was measured spectrophotometrically. Brain 5-HT levels were determined by the immunohistochemical method. Our findings indicate that the tryptophan suppresses food intake significantly in mice. Body weight decreased and brain TBARS levels increased significantly by repeated tryptophan treatment. Immunohistochemical detection showed that 5-HT levels increased by tryptophan administration. There is a link between increased 5-HT level and oxidative stress by tryptophan administration on brain tissue. Tryptophan at repeated doses should be exercised carefully in clinical practice. 相似文献
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Recent evidence suggests that non-muscle myosin IIB (NMIIB) contributes to smooth muscle contraction. This study was designed to determine the effects of NMIIB on the cross-bridge cycling rate. The cross-bridge cycling rate was investigated using sinusoidal analysis. Frequency analysis revealed two asymptotes in the Bode plot of the data; and the intersection of the asymptotes (corner frequency) was higher for the B+/− strain (8.73 ± 1.10 Hz vs 16.56 ± 1.26 Hz, P < 0.05), consistent with a higher overall cross-bridge cycling rate in heterozygous NMIIB KO (B+/−) vs WT mice. These results demonstrate that because of their long duty cycle, NMIIB cross-bridges act as an internal load on smooth muscle myosin to decrease the overall cross-bridge cycling rate and muscle Vmax during force maintenance. 相似文献
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Athar Ata Chad D. Iverson Kosmulalage S. Kalhari Sarfraz Akhter Jordan Betteridge Mohammad Hadi Meshkatalsadat Ilkay Orhan Bilge Sener 《Phytochemistry》2010,71(14-15):1780-1786
From the aerial parts of Buxus hyrcana, three triterpenoidal alkaloids, 17-oxo-3-benzoylbuxadine (1), buxhyrcamine (2), and 31-demethylcyclobuxoviridine (3), along with 16 known compounds, cyclobuxoviridine (4), Nb-dimethylcyclobuxoviricine (5), E-buxenone (6), Z-buxenone (7), moenjodaramine (8), homomoenjodarmine (9), buxamine A (10), buxamine B (11), 31-hydroxybuxamine B (12), N20-formylbuxaminol E (13), papillozine C (14), buxmicrophylline F (15), buxrugulosamine (16), cyclobuxophylline O (17), spirofornabuxine (18) and arbora-1,9(11)-dien-3-one (19) were isolated. Their structures were elucidated by using NMR spectroscopic methods. All of the compounds exhibited moderate to weak acetylcholinesterase, butyrylcholinesterase and glutathione S-transferase inhibitory activities. Compounds 1–19 also exhibited modest anti-fungal activities against Candida albicans. Compounds 1, 2, 8, 9 and 18 also exhibited weak anti-leishmanial activity. 相似文献
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Genome-wide mapping of DNA synthesis in Saccharomyces cerevisiae reveals that mechanisms preventing reinitiation of DNA replication are not redundant
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To maintain genomic stability, reinitiation of eukaryotic DNA replication within a single cell cycle is blocked by multiple mechanisms that inactivate or remove replication proteins after G1 phase. Consistent with the prevailing notion that these mechanisms are redundant, we previously showed that simultaneous deregulation of three replication proteins, ORC, Cdc6, and Mcm2-7, was necessary to cause detectable bulk re-replication in G2/M phase in Saccharomyces cerevisiae. In this study, we used microarray comparative genomic hybridization (CGH) to provide a more comprehensive and detailed analysis of re-replication. This genome-wide analysis suggests that reinitiation in G2/M phase primarily occurs at a subset of both active and latent origins, but is independent of chromosomal determinants that specify the use and timing of these origins in S phase. We demonstrate that re-replication can be induced within S phase, but differs in amount and location from re-replication in G2/M phase, illustrating the dynamic nature of DNA replication controls. Finally, we show that very limited re-replication can be detected by microarray CGH when only two replication proteins are deregulated, suggesting that the mechanisms blocking re-replication are not redundant. Therefore we propose that eukaryotic re-replication at levels below current detection limits may be more prevalent and a greater source of genomic instability than previously appreciated. 相似文献
36.
The purpose of this study was to ascertain whether vitamin C supplementation during chronic exercise training alters rat brain
antioxidant content. Female Wistar albino rats were exercised on a treadmill for 30 min/day for 6.5 weeks and were administered
daily intraperitoneal injections of vitamin C (20 mg/kg). After the training period, chronically exercised rats showed no
significant changes in total brain thiobarbituric acid reactive substances (TBARS) levels. In contrast, rats supplemented
with vitamin C during the training period showed significantly elevated brain TBARS levels. If such results were extrapolated
to man, where vitamin supplementation is a common practice, this would indicate that vitamin C supplementation may not protect
brain tissue against exercise-induced oxidative damage, in such circumstances, this water-soluble antioxidant behaves as a
pro-oxidant. (Mol Cell Biochem xxx: 135–138, 2005) 相似文献
37.
Ozer C Gönül B Elmas C Erdoüan D Ercan ZS 《Molecular and cellular biochemistry》2005,280(1-2):151-157
Dexfenfluramine is one of the anorectic drugs that suppresses food intake which acts via inhibition of reuptake of serotonin
into brain terminal. Gastrointestinal tract is the main source of peripheral serotonin which is involved in the regulation
of gastrointestinal motility. During the use of anorectic drugs, the antioxidant defence is affected especially by reactive
oxygen species.
The purpose of this study to search: The effect of dexfenfluramine on serotonin levels of ileum and the effect of dexfenfluramine
on ileal contractility and oxidative stress.
Materials and Methods: Twenty-two adult male Swiss-albino mice were divided two groups (1) Control, (2) Dexfenfluramine treated
(i.p. twice a day 0.2 mg kg−1 in 0.2 ml saline solution for 7 days). Animal body weights were recorded at the beginning and at the end of the experimental
period. Ileum tissues contractile responses to different concentrations of KCl and acethycholine were recorded on polygraph.
In the meantime ileal tissue malondialdehyde, a product of lipid peroxidation, and glutathione, endogenous antioxidant levels
were assessed by spectrophotometric methods. Ileal tissue serotonin level determined by immunohistochemical method. Body weights
decrease and ileal contractile response of acethycholine increased significantly by dexfenfluramine treatment. Meanwhile,
ileum glutathione levels decreased and malondialdehyde levels increased in dexfenfluramine treated group. Immunohistochemical
detection showed that ileal serotonin levels increased by dexfenfluramine treatments.
As a conclusion, there is a relationship between increased ileal contractility and oxidant status in dexfenfluramine treated
animals. These effects can be related by increased serotonin levels which is induced by dexfenfluramine in ileum. (Mol Cell
Biochem xxx: 151–157, 2005) 相似文献
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Stuart J. Lucas Kadriye Kahraman Bihter Avşar Richard J.A. Buggs Ipek Bilge 《The Plant journal : for cell and molecular biology》2021,105(5):1413-1430
The European hazelnut (Corylus avellana L.) is a tree crop of economic importance worldwide, but especially for northern Turkey, where the majority of production takes place. Hazelnut production is currently challenged by environmental stresses, such as a recent outbreak of severe powdery mildew disease; furthermore, allergy to hazelnuts is an increasing health concern in some regions. In order to provide a foundation for using the available hazelnut genetic resources for crop improvement, we produced a fully assembled genome sequence and annotation for a hazelnut species, from C. avellana cv. ‘Tombul’, one of the most important Turkish varieties. A hybrid sequencing strategy, combining short reads, long reads and proximity ligation methods, enabled us to resolve heterozygous regions and produce a high-quality 370-Mb assembly that agrees closely with cytogenetic studies and genetic maps of the 11 C. avellana chromosomes, and covers 97.8% of the estimated genome size. The genome includes 27 270 high-confidence protein-coding genes, over 20 000 of which were functionally annotated based on homology with known plant proteins. We focused particularly on gene families encoding hazelnut allergens, and the Mildew resistance Locus O (MLO) proteins that are an important susceptibility factor for powdery mildew. The complete assembly enabled us to differentiate between members of these families and to identify homologues that may be important in mildew disease and hazelnut allergy. These findings provide examples of how the genome can be used to guide research and to develop effective strategies for crop improvement in C. avellana. 相似文献
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Budama-Kilinc Yasemin Kecel-Gunduz Serda Cakir-Koc Rabia Aslan Bahar Bicak Bilge Kokcu Yagmur Ozel Aysen E. Akyuz Sevim 《International journal of peptide research and therapeutics》2021,27(3):2015-2028
International Journal of Peptide Research and Therapeutics - The aim of the current study was to design a drug delivery nano-system of natural growth-modulating peptide known as GHK that naturally... 相似文献