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131.
The effect of phorbol myristate acetate, phorbol dibutyrate, ethanol, dimethylsulfoxide, phenol, and seven metabolites of phenol on metabolic cooperation were assessed as a function of mutant cell recovery from populations of cocultivated hypoxanthine-guanine phosphoribosyl transferase-deficient mutant (HGPRT–) and wild-type (HGPRT+) Chinese hamster V79 lung fibroblasts. Phorbol myristate acetate and phorbol diputyrate, two established tumor promoters, were potent inhibitors of metabolic cooperation. Ethanol and dimethylsulfoxide, solvents commonly used to prepare chemicals for testing, weakly inhibited metabolic cooperation. Phenol and phenylglucuronide had no effect on metabolic cooperation. Four oxidative metabolites (1,4-benzoquinone, catechol, hydroxyquinol and quinol) inhibited metabolic cooperation. Phenylsulfate weakly inhibited metabolic cooperation. Conversely, 2-methoxyphenol, a methylated derivative of catechol, appeared to enhance metabolic cooperation. These results generallyAbbreviations CAS
Chemical Abstracts Service
- DMSO
dimethylsulfoxide
- ETOH
ethanol
- HGPRT
hypoxanthine-guanine phosphoribosyl transferase
- HGPRT+
HGPRT-competent
- HGPRT–
HGPRT-te]deficient
- MC
metabolic cooperation
- MC+
metabolic cooperation-competent
- MC–
metabolic cooperation-deficient
- MEM
minimum essential medium
- PDBu
phorbol dibutyrate
- PMA
phorbol myristate acetate
- 6TG
6-thioguanine
- 6TGr
6-thioguanine-resistant
- 6TGs
6-thioguanine-sensitive
- V79/MC assay
Chinese hamster V79 lung fibroblast assay for metabolic cooperation 相似文献
132.
133.
The diploid Phoebanthus tenuifolius and the tetraploid P. grandiflorus yielded identical complements of foliar flavonoid aglycones, including the compounds nepetin, jaceosidin, and hymenoxin. Flavonoid data do not resolve the origin of the tetraploid species. The similarity between the flavonoids of Phoebanthus and those earlier reported for Helianthus would support a merger of the two genera. 相似文献
134.
本文用放射免疫测定法(RIA),测定了200~290例中国四川成都市郊30~73岁的正常成年男性血清睾酮(T)促黄体激素(LH).卵泡刺激素(FSH)及泌乳激素(PRL)的水平及其分布,进行了不同年龄水平差异显著性的观察,见到睾酮与泌乳激素水平无显著差异,促黄体激素及卵泡刺激素水平,随年龄之增加而升高,差异有显著性,并测得它们在血清中水平的分布:LH、FSH及PRL均为对数正态公布,T既非正态又非对数正态,但其频率分布较对称,接近正态分布。 相似文献
135.
<正> 我们实验室曾报道,用胆酸盐透析法将猪心线粒体H~+-ATP酶嵌入大豆磷脂脂质体形成脂酶体时,透析液中Mg~(2+)的存在会降低脂酶体的膜脂流动性,并明显提高重建H~+-ATP酶的活性以及对寡霉素或DCCD的敏感性,因而推论Mg~(2+)的作用很可能是通过改变膜脂的物理状态,形成了维持H~+-ATP酶较高活性的合适构象。但共确切的作用机制仍 相似文献
136.
p38MAPK是丝裂原活化蛋白激酶(mitogen activated protein kinases,MAPK)家族的一个亚类,在高等脊椎动物免疫应答的信号转导过程中扮演着非常重要的角色。在日本七鳃鳗(Lampetra japonica)中发现,p38MAPK以两种异构体的形式存在。通过克隆它们的开放阅读框并进行同源序列比对和系统发育分析,鉴定它们分别为p38α(Lja-mapk14)和p38β(Lja-mapk11)。用混合菌刺激七鳃鳗,利用免疫印迹方法,检测Lja-mapk14在外周血类淋巴细胞、鳃组织和髓样小体中,分别在加强免疫36 h、24 h和24 h后,表达量达到峰值,分别为对照组的2.9、2.1和2.6倍;而Lja-mapk11在以上组织中,都在加强免疫36 h后达到表达量峰值,分别为对照组的2.2、2.5和6.3倍。实时荧光定量PCR检测发现,Lja-mapk14的mRNA表达水平在混合菌加强免疫36 h后,分别在类淋巴细胞、鳃组织和髓样小体中,上调2.3、1.5和3.4倍;而Lja-mapk11的则分别在类淋巴细胞、鳃组织和心肌中,上调1.3、2.6和1.6倍。以上结果在mRNA和蛋白质水平证明,Lja-mapk14和Lja-mapk11均参与七鳃鳗的免疫应答反应。采用B细胞和T细胞丝裂原LPS和PHA分别对七鳃鳗进行刺激,免疫印迹结果显示,Lja-mapk14和Lja-mapk11蛋白质表达量经LPS加强免疫36 h后,在类淋巴细胞、鳃组织和髓样小体中,上调表达1.3 ~ 4.1倍;而经PHA加强免疫36 h后,Lja-mapk14和Lja-mapk11在上述组织中表达量均不存在显著变化。以上结果说明,Lja-mapk14和Lja-mapk11可能参与了B细胞丝裂原LPS介导的VLRB类淋巴细胞亚群的免疫应答反应。 相似文献
137.
Joseph A. Aloi Thomas R. Insel Edward A. Mueller Dennis L. Murphy 《Life sciences》1984,34(14):1325-1331
The effects of m-chlorophenylpiperazine (mCPP), a serotonin receptor agonist, on the release of plasma prolactin (PRL), growth hormone (GH), and cortisol in the rhesus monkey were studied. mCPP was administered intravenously at doses of 0.5, 1.5, and 3.0 mg/kg. GH and cortisol were increased significantly at all doses whike PRL was significantly increased only following administration of 3.0 mg/kg mCPP. mCPP administration also produced behavioral alterations in each monkey, including sedation, penile erection, and defecation. PRL, GH and behavioral responses to mCPP were completely blocked by pretreatment with the serotonin anatgonist metergoline (MTG). However, pretreatment with MTG failed to entirely antagonize the cortisol response to mCPP. These data suggest that mCPP has prominent neuroendocrine and behavioral effects which are mediated, in part, by serotonergic mechanisms. 相似文献
138.
Ascorbic acid levels are commonly reported to be decreased in alcoholics. Although this deficiency could be due to dietary factors, there is evidence that ascorbic acid may be involved in the metabolism and acute effects of ethanol, possibly related to the pathogenesis of alcoholism. Therefore, we examined ethanol preference in guinea pigs receiving an ascorbate deficient a normal diet. Brain and spleen ascorbic acid levels were dramatically decreased, but ethanol preference was not altered by the acute dietary deficiency of this vitamin. In addition, an acute stressor (cold water swim), alone or in combination with ascorbate deficiency, had no effect on ethanol preference. At termination of the experiment, two measures of brain aminergic function (MAO activity and 3H-spiroperidol binding), purportedly altered by ethanol or ascorbic acid or both, were not associated with tissue ascorbate levels. 相似文献
139.
Cytokinin-induced switch in development in excised cotyledons of radiata pine cultured in vitro 总被引:2,自引:0,他引:2
Victor M. Villalobos Melvin J. Oliver Edward C. Yeung Trevor A. Thorpe 《Physiologia plantarum》1984,61(3):483-489
Cotyledons of Pinus radiata D. Don were cultured under shoot-forming (plus cytokinin) and elongating (minus cytokinin) conditions. Using. autoradiographic and precursor incorporation techniques, the sites and rate of macromolecular synthesis were examined during the first five days in culture. Active incorporation of 3 H-thymidine, 3 H-uridine and 3 H-leucine occurred. In shoot-forming cotyledons the incorporation became preferentially located in the epidermal and sub-epidermal cell layers in contact with the medium. In elongating cotyledons, in contrast, incorporation was randomly distributed, and the amount of incorporation declined with time. Biochemically, differences in DNA, RNA and total protein synthetic patterns were observed. In elongating cotyledons the rates of RNA and protein synthesis were higher during the first 48 h than in shoot-forming tissues, after which the synthetic rates were similar. Two peaks of newly formed DNA were observed in both tissues. These findings indicate that the cytokinin-induced changes in developmental pathways began within 24 h in culture. 相似文献
140.
David A. Greenberg Edward C. Cooper Adrienne Gordon Ivan Diamond 《Journal of neurochemistry》1984,42(4):1062-1068
Abstract: Ethanol appears to enhance γ-aminobutyric acid (GABA)-mediated synaptic transmission. Using radioligand binding techniques, we investigated the possibility that the GABA-benzodiazepine receptor complex is the site responsible for this effect. Ethanol at concentrations up to 100 m M failed to alter binding of [3 H]flunitrazepam (FNZ), [3 H]Ro 15-1788, or [3 H]methyl-γ-carboline-3-carboxylate (MBCC) to benzodiazepine receptors, or of [3 H]muscimol to GABA receptors in rat brain membranes. Scatchard analyses of the binding of these radioligands at 4°C and 37°C revealed no significant effects of 100 m M ethanol on receptor affinity or number. A variety of drugs as well as chloride ion increased binding of [3 H]FNZ and/or [3 H]muscimol, but these influences were not modified by ethanol. These findings indicate that ethanol probably potentiates GABAergic neurotransmission at a signal transduction site beyond the GABA-benzodiazepine receptor complex. 相似文献