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1.
Analysis of monoamines and their metabolites by high performance liquid chromatography with coulometric electrochemical detection 总被引:2,自引:0,他引:2
High performance liquid chromatography with coulometric electrochemical detection has been used to achieve simultaneous determination of norepinephrine, epinephrine, 5-hydroxytryptophan, normetanephrine, dopamine, metanephrine, 3,4-dihydroxyphenylacetic acid, N-acetyldopamine, tyramine, tryptophan, 5-hydroxyindoleacetic acid, 5-hydroxytryptamine, N-acetyl-5-hydroxytryptamine, homovanillic acid, tyrosine, p-octopamine, N-acetyl-p-octopamine, and p-synephrine. The procedure has been applied to study monoamine degradation in the insect brain and to demonstrate that N-acetylation rather than oxidative deamination is the primary route of monoamine catabolism in insects. 相似文献
2.
作者在广东省梅县市发现四个吸虫新种:1.鼠丽色吸虫,新种Reesella ratta sp. nov., 2.后囊蛙蠕吸虫,新种Batrachotrema optstosacca sp. nov., 3.梅县后平睾吸虫,新种Opisthioparorchis meixianensis sp. nov., 4.大卵后平睾吸虫,新种Opisthioparorchis megaloonos sp. nov.,它们分别归隶于蹲茎科Cathaemasiidae及蛙蠕科Bstrachotrematidae。模式标本保存于中山医科大学寄生虫学研究所。 相似文献
3.
The role of proctolin has been further investigated in the locust (Locusta migratoria) mandibular closer muscles. Radioactive calcium uptake measurements were made using protease-dissociated muscle cells. Both the phorbol ester, phorbol-12,13-dibutyrate, and proctolin produce tonic contractions which are associated with the influx of extracellular calcium. The thresholds for proctolin and the phorbol ester to contract the muscle were 1-10 nM and 10-100nM, respectively, while their respective thresholds for evoking measurable calcium influx into the muscle cells were 0.1-1 nM for proctolin, and 0.1-1 pM for phorbol-12,13-dibutyrate. The effect of phorbol-12,13-dibutyrate is blocked by a number of protein kinase inhibitors (at a concentration of 0.1 mM), suggesting that an activation of a protein kinase can lead to calcium influx. These inhibitors, however, do not block the effect of proctolin, indicating that these two compounds work through different pathways, possibly converging on the same final target. In light of this finding, a number of other compounds have been tested to try to ascertain how proctolin mediates an increased calcium influx. 相似文献
4.
Infrared spectroscopic study of photoreceptor membrane and purple membrane. Protein secondary structure and hydrogen deuterium exchange 总被引:4,自引:0,他引:4
Infrared spectroscopy in the interval from 1800 to 1300 cm-1 has been used to investigate the secondary structure and the hydrogen/deuterium exchange behavior of bacteriorhodopsin and bovine rhodopsin in their respective native membranes. The amide I' and amide II' regions from spectra of membrane suspensions in D2O were decomposed into constituent bands by use of a curve-fitting procedure. The amide I' bands could be fit with a minimum of three theoretical components having peak positions at 1664, 1638, and 1625 cm-1 for bacteriorhodopsin and 1657, 1639, and 1625 cm-1 for rhodopsin. For both of these membrane proteins, the amide I' spectrum suggests that alpha-helix is the predominant form of peptide chain secondary structure, but that a substantial amount of beta-sheet conformation is present as well. The shape of the amide I' band was pH-sensitive for photoreceptor membranes, but not for purple membrane, indicating that membrane-bound rhodopsin undergoes a conformation change at acidic pH. Peptide hydrogen exchange of bacteriorhodopsin and rhodopsin was monitored by observing the change in the ratio of integrated absorbance (Aamide II'/Aamide I') during the interval from 1.5 to 25 h after membranes were introduced into buffered D2O. The fraction of peptide groups in a very slowly exchanging secondary structure was estimated to be 0.71 for bacteriorhodopsin at pD 7. The corresponding fraction in vertebrate rhodopsin was estimated to be less than or equal to 0.60. These findings are discussed in relationship to previous studies of hydrogen exchange behavior and to structural models for both proteins. 相似文献
5.
Chlordimeform (CDM) and demethylchloridimeform (DCDM) mimic the action of octopamine in elevating adenylate cyclase activity in intact nerve cords of the American cockroach, Periplaneta americana. At a concentration of 1 x 10(-5)M, DCDM (13.5x increase within 20 minutes) is a more potent effector of the response than CDM (3x increase within 20 minutes), but both compounds show less efficacy than octopamine (23.5x increase within 15 minutes). DCDM also mimics the stimulatory effect of octopamine on adenylate cyclase activity in nerve cord homogenates whereas CDM has no demonstrable effect on this preparation. The octopamine- and DCDM-induced responses are competitively inhibited by phentolamine (1 x 10(-6)M) and cyproheptadine (1 x 10(-6)M) but not by propranolol (1 x 10(-6)M). DCDM and CDM inhibit the octopamine-induced activation of adenylate cyclase by 33% and 44% respectively. The results are discussed in light of the proposal that DCDM serves as a partial agonist and CDM as an antagonist of the octopamine receptor. 相似文献
6.
对我国52种微茎类吸虫的18项成虫形态学特征进行主成分分析,结果表明:卵巢位置、子宫延伸位置等7项性状对第一主成分贡献较大,提示描述器官位置的指标是重要的分类依据。52个虫种在前三个主成分上的排序图显示应将其划分成4个亚科。 相似文献
7.
本文就萤叶甲亚科中柱萤叶甲属鞘翅具黑色刻点的种类进行研究,共记述4种,我国已记录3种,其中1种为新种。 相似文献
8.
9.
维生素C·Cu·菲咯啉系统对DNA的定位损伤 总被引:4,自引:0,他引:4
维生素C·Cu·菲咯啉系统对DNA的定位损伤柯德森,王爱国,罗广华(中国科学院华南植物研究所,广州510650)关键词活性氧;DNA;定位损伤活性氧对DNA的损伤已经被很多工作所证实”””,这种伤害是由0B”直接作用于DNA所引起的”’“。但是OH’... 相似文献
10.
本文报道在湛江市附近海域海鸟体内获得的两种吸虫,经鉴定为新种,命名为巨口类茎吸虫,新种Microphalloides macrostonrs sp.nov.,珊瑚多黄吸虫,新种Multivitellus coralius sp.nov. 相似文献