BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH
·
2014
·Vol. 47
·期 12
·1068-1074
·
IF 1.034
Yao Q.Y.,Chen D.P.,Ye D.M.,Diao Y.P.,Lin Y.
Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca2+dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.
研究领域:
药理学
·
消化系统生理学
✓ 已验证
DOI
PubMed
高影响因子
ACTA PHARMACOLOGICA SINICA
·
2016
·Vol. 37
·期 8
·1091-1100
·
IF 3.166
Xiong Yong-jian,Chu Hong-wei,Lin Yuan,Han Fang,Li Ya-chan,Wang Ai-guo,Wang Fu-jin,Chen Da-peng,Wang Jing-yu
Aim: Postoperative ileus (POI) is a postoperative dysmotility disorder of gastrointestinal tract, which remains one of the most perplexing problems in medicine. In the present study we investigated the effects of hesperidin, a major flavonoid in sweet oranges and lemons, on POI in rats. Methods: SD rats were administered hesperidin (5, 20, and 80 mg·kg −1 ·d −1 , ig) for 3 consecutive days. POI operation (gently manipulating the cecum for 1 min) was performed on d 2. The gastrointestinal motility and isolated intestinal contraction were examined 1 d after the operation. Then the myosin phosphorylation and inflammatory responses in cecum tissue were assessed. Smooth muscle cells were isolated from rat small intestine for in vitro experiments. Results: The gastric emptying and intestinal transit were significantly decreased in POI rats, which were reversed by administration of hesperidin. In ileum and cecum preparations of POI rats in vitro , hesperidin (2.5–160 μmol/L) dose-dependently increased the spontaneous contraction amplitudes without affecting the contractile frequency, which was blocked by the myosin light chain kinase (MLCK) inhibitor ML-7 or verapamil, but not by TTX. Furthermore, administration of hesperidin increased the phosphorylation of MLC 20 in the cecum tissue of POI rats. Moreover, administration of hesperidin reversed the increased levels of inflammatory cytokines, iNOS and COX-2 in cecum tissue of POI rats. In freshly isolated intestinal smooth muscle cells, hesperidin (5–80 μmol/L) dose-dependently increased the intracellular Ca 2+ concentration as well as the phosphorylation of MLC 20 , which was abrogated by ML-7 or siRNA that knocked down MLCK. Conclusion: Oral administration of hesperidin effectively alleviates rat POI through inhibition of inflammatory responses and stimulation of Ca 2+ -dependent MLC phosphorylation.
研究领域:
药理学
·
胃肠病学
·
外科
✓ 已验证
DOI
PubMed
高影响因子
PLANT PHYSIOLOGY AND BIOCHEMISTRY
·
2024
·
IF 6.1
Chenghao Huang,Fei Huang,Xuke Wang,Dongru Wang,Jiawei Wang,Xinhua Zhan
Polycyclic aromatic hydrocarbons (PAHs) constitute a category of persistent organic contaminants that possess the potential to induce carcinogenic, teratogenic, and mutagenic consequences. Our previous findings have revealed that plant roots actively take up PAHs through co-transport with protons, and auxin can promote PAHs uptake by wheat roots. It remains unclear whether nitric oxide (NO), a signaling molecule involved in numerous physiological processes in plants and downstream of auxin, can affect PAHs uptake by plant roots. In our study, 50 μmol/L sodium nitroprusside (SNP) significantly enhanced phenanthrene uptake after 4 h of exposure. After the addition of SNP (50 μmol/L), the H + flux on root surface increased, and H + -ATPase activity was activated, indicating that exogenous NO promotes phenanthrene uptake by plant roots via activating H + -ATPase. By studying the effects of 50 μmol/L cyclic guanosine monophosphate (cGMP), 5 mmol/L Ca 2+ , and 50 μmol/L adenosine monophosphate (AMP) on phenanthrene uptake by ryegrass roots and measuring root calcium-dependent protein kinases (CDPK) activity, we demonstrated that exogenous NO promotes phenanthrene uptake through the signaling pathway of NO, cGMP, Ca 2+ , CDPK, 14-3-3 protein and H + -ATPase. The results contribute significant insights into elucidating the underlying mechanisms of NO modulating PAHs absorption by plant roots, thereby offering crucial strategies for advancing food safety measures and enhancing the phytoremediation potential of soils and waters contaminated with PAHs.
研究领域:
环境科学
·
植物生理学
·
植物修复
·
土壤污染
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Laifeng Lu,Ying Yang,Haoran Zhang,Dandan Sun,Zhenjing Li,Qingbin Guo,Changlu Wang,Liping Qiao
Mechanical wounding causes significant economic losses of fresh produce due to accelerated senescence and spoilage as well as loss of nutritional value. Here, pre-application of oligogalacturonides (OGs) enzymatically hydrolyzed from apple pectin effectively reduced the healing times of mechanical wounds from>24 h in mock groups to 12 h, and the Botrytis cinerea infection rate was reduced from 37.5% to 12.5%. OGs accordingly increased callose deposition; SlPR1, SlPAL and SlHCT gene expression; and phenylalanine ammonia-lyase (PAL) activity around the wounds. Inhibition of Ca 2+ signaling using the inhibitor Ruthenium Red markedly inhibited OG accelerated healing of mechanical wounding on fruit. SlPG2, SlEXP1 , and SlCEL2 mRNAs accumulation was reduced in OG-elicited tomato fruit compared to water-treated fruit with subsequent retardation of the fruit softening during ripening. These results indicated that apple pectin OGs accelerate wound healing and inhibit fruit softening by activating calcium signaling in tomato fruits during postharvest storage.
研究领域:
植物科学
·
采后生理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOLOGICAL TRACE ELEMENT RESEARCH
·
2023
·
IF 3.9
Peng Huixin,Huang Yanxin,Wei Guangji,Pang Yanfang,Yuan Huixiong,Zou Xiong,Xie Yu’an,Chen Wencheng
Aluminum contamination is a growing environmental and public health concern, and aluminum testicular toxicity has been reported in male rats; however, the underlying mechanisms of this toxicity are unclear. The objective of this study was to investigate the effects of exposure to aluminum chloride (AlCl 3 ) on alterations in the levels of sex hormones (testosterone [T], luteinizing hormone [LH], and follicle-stimulating hormone [FSH]) and testicular damage. Additionally, the mechanisms of toxicity in the testes of AlCl 3 -exposed rats were analyzed by proteomics. Three different concentrations of AlCl 3 were administered to rats. The results demonstrated a decrease in T, LH, and FSH levels with increasing concentrations of AlCl 3 exposure. HE staining results revealed that the spermatogenic cells in the AlCl 3 -exposed rats were widened, disorganized, or absent, with increased severe tissue destruction at higher concentrations of AlCl 3 exposure. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses revealed that differentially expressed proteins (DEPs) after AlCl 3 exposure were primarily associated with various metabolic processes, sperm fibrous sheath, calcium-dependent protein binding, oxidative phosphorylation, and ribosomes. Subsequently, DEPs from each group were subjected to protein-protein interaction (PPI) analysis followed by the screening of interactional key DEPs. Western blot experiments validated the proteomics data, revealing the downregulation of sperm-related DEPs (AKAP4, ODF1, and OAZ3) and upregulation of regulatory ribosome-associated protein (UBA52) and mitochondrial ribosomal protein (MRPL32). These findings provide a basis for studying the mechanism of testicular toxicity due to AlCl 3 exposure.
研究领域:
毒理学
·
环境健康
·
生殖生物学
·
蛋白质组学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）