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21.
Antidiuretic effects of oxytocin in the Brattleboro rat 总被引:1,自引:0,他引:1
J. Lyness A. G. Robinson M. N. Sheridan D. M. Gash 《Cellular and molecular life sciences : CMLS》1985,41(11):1444-1446
Summary The antidiuretic activity of oxytocin (OT) was measured in Brattleboro rats with congenital diabetes insipidus. A dose dependent antidiuretic response was found in animals receiving chronic infusions of 0.1 g/h, 1.0 g/h, and 5 g/h of OT. OT infused at the rate of 5 g/h over a 7-day period completely reversed the symptoms of diabetes insipidus. The results support the concept that OT serves as a weak agonist of vasopressin at the level of the kidney and at pharmacological levels exhibits antidiuretic activity. 相似文献
22.
H. Tsuchiya M. Sato M. Iinuma J. Yokoyama M. Ohyama T. Tanaka I. Takase I. Namikawa 《Cellular and molecular life sciences : CMLS》1994,50(9):846-849
Phytoalexins, defensive compounds produced by plants against microbial infections, were purified fromSophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2,4-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 g/ml. 相似文献
23.
M. -P. Sauviat J. -M. Chesnais J. Diacono J. -F. Biard J. -F. Verbist 《Cellular and molecular life sciences : CMLS》1994,50(10):926-930
Bistramide A, a new toxin isolated from the UrochordateLissoclinum bistratum Sluiter, was applied to rat auricular heart muscle bundles. At a stimulation frequency of 0.2 Hz, the toxin induces a dose-dependent reduction of the stimulated twitch tension force; it decreases
and shortens the duration of the plateau and the slow repolarizing phase of the action potential. In the control solution, switching from a stimulation frequency of 0.2 Hz to 1 Hz decreases the force with which a positive potentiation develops either at a maintained high frequency or after switching from 1 Hz to 0.2 Hz. Bistramide A reduces both the force evoked at 1 Hz and the potentiation. The data suggest that Bistramide A blocks Na+ conductance; inhibits Ca++ channels in a time-and frequency-dependent manner; reduces Na+–Ca++ exchange activity; but does not modify the ability of the sarcoplasmic reticulum to be refilled although the rate of Ca++ accumulation is decreased. 相似文献
24.
牛蒡中多酚氧化酶的活性及其影响因素研究 总被引:6,自引:0,他引:6
对牛蒡中所含的多酚氧化酶的活性及其影响因素的研究表明,牛蒡中多酚氧化酶的适宜pH值是6.0~7.5,适宜温度45℃,较有效的抑制剂是2%钾明矾和0.02%SSA的混合液,或0.58%磷酸和0.02%SSA的混合液.用此溶液浸泡过的牛蒡,再用HPE薄膜袋包装后,在-40℃下速冻,放在-18℃冷冻库保存,贮藏期达6个月以上. 相似文献
25.
用CNDO/2量化方法计算了35个苯甲酰类化合物的量化指数,并应用模式识别方法研究了该类化合物的结构对治疗患L1210肿瘤小鼠药效的影响,得到满意的分类图。结果表明化合物的抗癌活性的主要影响因素为CQS、ELUMO、ESHEP和π,药物的抗癌活性主要是通过抑制核苷酸还原酶所致,而且化合物在体内到达受体的过程和难易程度对药效的影响较大。 相似文献
26.
The pure phase of praseodymium orthovanadate (PrVO4) has been prepared by the citrate method. The active site of Pr-VO4 was studied by ESR, NO-TPD, O2-TPD and18O2-isotope exchange methods. The results of ESR and NO-TPD confirmed the presence of V4+ in the catalyst.18O2-isotope exchange was through a single exchange procedure. From the result of O2 + TPD and the kinetic study of18O2-isotope exchange, one can reach a conclusion that the V4+ species associated with oxygen vacancies are the site for O2 activation. The adsorbed O2 or O− are the active oxygen species in propane oxidative dehydrogenation. 相似文献
27.
Cytosine deaminase gene ofEscherichia coli strain H-30 was cloned, and its initiation codon of ‘GTG’ was mutated to ‘ATG’ by PCR. Prokaryotic recombinant expression
vector pBV220-CD was constructed. Clone with high enzyme activity were selected by detecting their specific activity of cytosine
deaminase. 5-FC(5-FC, 5-fluorocytosine) could induce the lethal toxicity to cells containing active CD gene. DNA sequence
analysis indicated that there were 16 altered bases and 5 of them resulted in the alteration of amino acids in predicted peptide
by comparing DNA sequence of the clone H-30-CD-11 with high enzyme activity with CD gene reported in Gene Bank. 相似文献
28.
1673K下,采用-MoCr+Cr2O3ZrO2(MgO){Cu+Cr}aloy+(Cr2O3)slagMo+固体电解质电池测定了BaOBaF2Cr2O3渣系中Cr2O3的活度.研究结果表明,Cr2O3的活度随其浓度升高而升高,随XBaO/XBaF2升高而降低.根据实验及X射线衍射结果推测了该渣系的等温相图,并作出了该渣系中Cr2O3的等活度图. 相似文献
29.
土壤酶与土壤肥力关系的研究 总被引:12,自引:0,他引:12
论述了各种土壤酶的特性及其相互关系;土壤酶活性与土壤肥力因素之间密切相关;施肥对土壤酶活性有着明显的影响,用酶活性的总体进行土壤肥力水平评价的可能性。 相似文献
30.
生物资源是人类生存环境的重要组成部分,是人类赖以生活的物质基础。本文探讨了人类活动对生物资源直接和间接的影响,指出人类的许多经济和社会活动已对生物资源构成了严重威胁,如毁林开荒、乱捕滥猎、盲目引种、人口剧增、环境污染等。只有尽快采取措施,制定政策法规,加强宣传教育,积极保护环境和生物资源,人类才能与大自然合谐统一、健康持续发展下去。 相似文献