Abstract：
:The effect of various fractions of black tea [(Camellia Sinensis) (L) O. Kuntze (Theaceae)] on the function of mammalian skeletomotor apparatus was studied. The theaflavin fraction (Tfs) produced a concentration- dependent facilitation of indirect twitch responses of the rat phrenic nerve diaphragm preparation and the facilitation was dependent on the amount of calcium present in the bathing fluid. Nifedipine reduced the facilitatory effect of Tfs as a function of its concentration. Tfs failed to produce facilitation when the twitch height was reduced to about 50% of the control value in presence of magnesium chloride. Tfs completely antagonized the submaximal paralytic effect of d- tubocurarine and decamethonium bromide. Tfs did not have any effect on direct twitch responses or on acetylcholine (Ach) and potassium chloride (KCl) induced contractures of denervated diaphragm. The results revealed that the site of action of Tfs is on the contractile mechanism of the voluntary muscle and point to a critical role of calcium in the mechanism of action of Tfs. N omega-nitro-L-arginine-methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, antagonized both the facilitatory and inhibitory effects on indirect twitch responses of rat diaphragm induced by L-arginine and Tfs when the phrenic nerve was stimulated at 5 Hz and 50 Hz respectively. The thearubigin (Trs) fraction of black tea and the aqueous part which is completely devoid of Tfs, did not potentiate the twitch responses. The findings suggest that Tfs have a potentiating effect on the contractile mechanism of skeletal muscle and that calcium and nitric oxide may modulate this action of Tfs.
journal_name
Life Scijournal_title
Life sciencesauthors
Basu S,Chaudhuri T,Chauhan SP,Das Gupta AK,Chaudhury L,Vedasiromoni JRdoi
10.1016/j.lfs.2004.12.018subject
Has Abstractpub_date
2005-05-13 00:00:00pages
3081-8issue
26eissn
0024-3205issn
1879-0631pii
S0024-3205(05)00098-6journal_volume
76pub_type
杂志文章相关文献
LIFE SCIENCES文献大全abstract：:In canine renal tubular cells, the effect of Y-24180, a presumed specific platelet activating factor (PAF) receptor antagonist, on intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured by using fura-2 as a Ca(2+)-sensitive fluorescent probe. Y-24180 (0.1-10 microM) caused a rapid and sustained [Ca(2+)](i) rise...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2003.09.033
更新日期：2004-01-02 00:00:00
abstract：AIMS:To evaluate potential agents of therapeutic value in tissue inflammation, we studied norcantharidin (NCTD) and its derivatives for their effects on immune responses of human peripheral blood mononuclear cells (PBMC) in vitro. MAIN METHODS:PBMC proliferation was evaluated by tritiated thymidine uptake method. The ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2008.11.020
更新日期：2009-02-13 00:00:00
abstract：AIMS:Obesity is associated with increased cardiovascular morbidity and mortality. It is accompanied by augmented O-linked β-N-acetylglucosamine (O-GlcNAc) modification of proteins via increasing hexosamine biosynthetic pathway (HBP) flux. However, the changes and regulation of the O-GlcNAc levels induced by obesity are...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2019.02.036
更新日期：2019-04-01 00:00:00
abstract：:The vascular endothelium is recognized as a barrier between blood and blood vessel wall. The abnormality of vascular endothelium is critical for atherosclerosis, hypertension and diabetes. Oxidative stress, inflammation, obesity, hyperlipidemia and insulin resistance are major contributors to endothelial dysfunction i...
journal_title：Life sciences
pub_type： 杂志文章,评审
doi：10.1016/j.lfs.2016.11.005
更新日期：2016-12-15 00:00:00
abstract：:We have measured circulating concentrations of gamma 3 Melanocyte Stimulating Hormone (MSH) in fetal sheep between 111 and 145 days gestation. There was no significant effect of gestational age on the fetal plasma concentrations of gamma 3 MSH throughout this period. We have examined the role of gamma-MSH related pept...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(89)90618-8
更新日期：1989-01-01 00:00:00
abstract：:SARS-CoV-2 infection or COVID-19 has become a worldwide pandemic; however, effective treatment for COVID-19 remains to be established. Along with acute respiratory distress syndrome (ARDS), new and old cardiovascular injuries are important causes of significant morbidity and mortality in COVID-19. Exploring new approa...
journal_title：Life sciences
pub_type： 杂志文章,评审
doi：10.1016/j.lfs.2021.119130
更新日期：2021-01-26 00:00:00
abstract：AIM:The aim of this study was to investigate the effect of protolichesterinic acid, a lichen secondary metabolite, on anti-proliferative activity of doxorubicin in three human cancer cell lines, HeLa, SH-SY5Y and K562 cells. MAIN METHODS:The data obtained from MTT assays, performed on cells treated with protolichester...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2016.06.023
更新日期：2016-08-01 00:00:00
abstract：:The effects of pretreatment with selective mu-, delta- and kappa-opioid receptor antagonists on the enhancement of the pentobarbital-induced loss of the righting reflex by morphine were examined in mice. Mice injected with pentobarbital (50 mg/kg, i.p.) showed an increased duration for the loss of the righting reflex ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(96)00540-1
更新日期：1996-01-01 00:00:00
abstract：:Bacitracin (BAC) U.S.P., obtained in the form of sterile powder, elicits dose-dependent and non-tachyphylactic contractions of the rabbit isolated aorta and of other rabbit vessels. The use of several pharmacologic antagonists suggests that BAC is a 5-hydroxytryptamine mimetic in aortic strips, since the antibiotic is...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(90)90355-u
更新日期：1990-01-01 00:00:00
abstract：:Neurological diseases are becoming increasingly prominent worldwide due to rapidly aging populations, which greatly contributes to increasing healthcare costs. The development of neuroprotective drugs has so far proven exceptionally difficult due to the blood-brain barrier. One novel approach to address this challenge...
journal_title：Life sciences
pub_type： 杂志文章,评审
doi：10.1016/j.lfs.2017.12.025
更新日期：2018-02-15 00:00:00
abstract：AIMS:Mancozeb is a dithiocarbamate fungicide known to be genotoxic and induces tumors in rodents at various sites. There is no report in the literature about its genotoxicity in humans. Here, we investigated the association between mancozeb exposure and induction of genotoxic and proapoptotic changes in cultured human ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2011.12.013
更新日期：2012-06-06 00:00:00
abstract：:The tumor promoter okadaic acid (OKA), is a marine toxin of algal origin, identified as a potent inhibitor of protein phosphatases 1 and 2A, and possibly enhancing calcium influx through voltage dependent calcium channels (VSSC). We now report that OKA at concentrations as low as 0.5 nM produced neurotoxicity, charact...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(91)90398-u
更新日期：1991-01-01 00:00:00
abstract：:Behavioral Hypersensitivity (BH) to dopamine agonists occurs following chronic treatment with most neuroleptics including haloperidol. In the present study we observed that the concurrent administration of thioridazine and haloperidol prevented the development of BH. In contrast, another neuroleptic, fluphenazine, coa...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(86)90120-7
更新日期：1986-05-12 00:00:00
abstract：AIMS:Head and neck squamous cell carcinoma (HNSCC) is an highly aggressive tumor with heterogeneous prognosis. We here report that immune-related genes (IRGs) could effectively distinguish prognostically different HNSCC patients. MATERIALS AND METHODS:MRNA levels of 1333 IRGs that from ImmPort database in HNSCC sample...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2020.117906
更新日期：2020-09-01 00:00:00
abstract：:The level of hepatic lipidperoxides in chick embryos was determined during cataract formation resulting from glucocorticoid treatment. When 15 day old chick embryos were administered 0.25 mumol of hydrocortisone acetate their hepatic lipidperoxide level, determined by thio-barbituric acid, increased after a lag time o...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(84)90664-7
更新日期：1984-08-27 00:00:00
abstract：:Different receptors mediating the release of endothelium-derived nitric oxide (EDNO) have been identified at endothelial level. In the present study we aimed to characterise, on rabbit aorta by means of pharmacological tools, the generation of EDNO by receptors located on endothelial cell membrane (M3, P2u, P2y) and b...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(97)01144-2
更新日期：1998-01-01 00:00:00
abstract：:Vitamin E treatment was found to lower blood pressure, and increase membrane fluidity in rats. The objectives of this study were to investigate the effects of the antioxidant, vitamin E, on the blood pressure and erythrocyte membrane fluidity in spontaneously hypertensive (SHR) and normotensive (WKY) rats. Membrane fl...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(00)00775-x
更新日期：2000-09-01 00:00:00
abstract：:The influence of stressful experiences on the development of vacuous chewing movements (VCM) was investigated in non-medicated rats. After an initial baseline period one group of rats was housed in a noisy environment while another group was housed in quiet surroundings. The development of VCM was recorded during a 16...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(91)90146-3
更新日期：1991-01-01 00:00:00
abstract：AIMS:Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, has been reported to be a novel marker for the progression of chronic kidney disease (CKD). We have recently found that accumulation of ADMA could trigger peritubular capillary loss, thus contributing to tubulointerstitial ischemia ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2009.03.018
更新日期：2009-06-05 00:00:00
abstract：:The hyperphagia and rapid body weight gain normally observed in young obese (ob/ob) mice were abolished by removal of their adrenal glands, whereas food intake and weight gain of lean mice were not significantly affected by adrenalectomy. Adrenalectomy lowered body energy density (kcal/g carcass) in obese mice more th...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(84)90056-0
更新日期：1984-04-09 00:00:00
abstract：:We find a significantly lower level of specific [3H]nicotine binding in the fetal rat forebrain of 20 day gestational age as compared to adult rat tissue, and a progressive increase in the [3H]nicotine binding in the early neonatal forebrain, reaching adult level at 14-28 days of age. The maximal binding sites (Bmax) ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(86)90057-3
更新日期：1986-02-17 00:00:00
abstract：:Alzheimer's disease (AD) is the most common form of dementia worldwide. β-amyloid peptide (Aβ) is currently assumed to be the main cause of synaptic dysfunction and cognitive impairments in AD, but the molecular signaling pathways underlying its neurotoxic consequences have not yet been completely explored. Additional...
journal_title：Life sciences
pub_type： 杂志文章,评审
doi：10.1016/j.lfs.2020.118020
更新日期：2020-09-15 00:00:00
abstract：:The effects of aporphines and secoaporphines on glucose uptake by isolated intestinal brush-border membrane vesicles (BBMV) or basolateral membrane vesicles (BLMV) and glucose absorption during in situ intestinal perfusion were studied. Of the tested compounds, N-allylsecoboldine was the most potent glucose uptake inh...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2005.12.031
更新日期：2006-06-06 00:00:00
abstract：AIMS:Recent evidence has shown that systemic administration of sulfonylureas and biguanides block the diclofenac-induced antinociception, but not the effect produced by indomethacin. However, there are no reports about the peripheral interaction between analgesics and the biguanides metformin and phenformin. Therefore,...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2011.10.009
更新日期：2012-01-02 00:00:00
abstract：:3H-Flunitrazepam (FNZP) binding was examined in a crude membrane fraction obtained from rat interscapular brown adipose tissue (IBAT). A single population of binding sites was apparent with dissociation constant (KD) = 0.47 +/- 0.04 microM and maximal number of binding sites (Bmax) = 31 +/- 5 pmol.mg prot-1. From the ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(88)90077-x
更新日期：1988-01-01 00:00:00
abstract：AIMS:Baicalein is a widely used Chinese herbal medicine extracted from Labiatae plants Scutellaria baicalensis Georgi's dry root, which has multiple pharmacological activities. However, the precise mechanism of baicalein against myocardial remodeling remains poorly understood. The aim of our study was to investigate th...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2015.12.036
更新日期：2016-01-15 00:00:00
abstract：:1,25-dihydroxyvitamin D3 has important physiological effects such as calcium transport and cell growth and differentiation. These biological effects are mediated by their binding to specific intracellular receptor termed vitamin D receptor (VDR). VDR mRNA expression has been demonstrated in several tissues, but to dat...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(96)00586-3
更新日期：1997-01-01 00:00:00
abstract：:Previous studies from this laboratory have shown that rats with experimental cirrhosis of the liver induced by the combined administration of oral phenobarbital and inhaled carbon tetrachloride show an hyperdynamic status with enhanced cardiac output (CO), and decreased mean arterial pressure (MAP) and peripheral vasc...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(86)90531-x
更新日期：1986-07-21 00:00:00
abstract：:Following a report that nortriptyline was found useful in the control of enuresis in adults, presumably as an anticholinergic, its likely mechanism of action and apparent bladder specificity have now been investigated in vitro. The ratios of anticholinergic potencies (reciprocal of dissociation contents, Ki) for four ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(87)90093-2
更新日期：1987-05-04 00:00:00
abstract：AIMS:LexA protein is a transcriptional repressor which regulates the expression of more than 60 genes belonging to the SOS global regulatory network activated by damages to bacterial DNA. Considering its role in bacteria, LexA represents a key target to counteract bacterial resistance: the possibility to modulate SOS r...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2019.117116
更新日期：2020-01-15 00:00:00
