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谷氨酸脱氢酶(glutamate dehydrogenase,GDH)可通过逆催化谷氨酸脱氨参与氨基酸代谢,也可生产合成氨,参与氮代谢。实验克隆得到达氏鳇(Huso dauricus)谷氨酸脱氢酶基因(gdh)的开放阅读框序列。该序列全长为1 635 bp,编码544个氨基酸。氨基酸序列多重比对结果显示达氏鳇GDH与其它脊椎动物的序列一致性较高。进一步的系统进化树分析发现,达氏鳇GDH与两栖类、爬行类及哺乳类聚为一支。组织表达分析结果表明,达氏鳇gdh的mRNA在各组织中都有分布,并且在肠中转录水平最高。随后,采用荧光定量PCR分析了饲料中添加双低菜粕对达氏鳇蛋白质代谢相关基因(gdh、氨肽酶N apN、小肽转运载体pepT1)及应激反应相关的热休克蛋白(hsp 90)基因表达的影响。在肝脏中,不同饲料投喂组gdh和hsp90的转录水平没有显著差异。在肠中,菜粕组gdh及apN基因的转录水平显著高于基础饲料组;菜粕组pepT1基因的转录水平也高于基础饲料组,但是没有显著性差异。以上结果表明,植物蛋白原料菜粕添加可引起达氏鳇肠道中蛋白质代谢水平上升,而不引起鱼体的应激反应。 相似文献
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耕作方式与秸秆还田对冬小麦–夏玉米轮作系统中干物质生产和水分利用效率的影响 总被引：9，自引：0，他引：9
为探讨黄淮海地区一年两熟制下土壤耕作方式与秸秆还田相结合的适宜模式,2010—2012年进行了两年度的田间试验,研究不同处理对冬小麦–夏玉米轮作系统干物质生产和水分利用效率的影响。通过比较常规耕作+秸秆还田、常规耕作+无秸秆还田、深耕+秸秆还田、深耕+无秸秆还田、深松+秸秆还田、深松+无秸秆还田6个处理,发现深松(耕)与秸秆还田可以增加冬小麦和夏玉米的农田耗水量,降低休闲期农田耗水量,提高作物叶片相对含水量、净光合速率、蒸腾速率和茎秆伤流量,促进植株干物质积累,进而提高作物籽粒产量和水分利用效率。耕作方式与秸秆还田对冬小麦和夏玉米的干物质生产和水分利用效率存在显著交互作用。与常规耕作+无秸秆还田相比,深耕+秸秆还田和深松+秸秆还田处理的作物干物质积累量分别提高19.3%和22.9%,周年作物产量分别提高18.0%和19.3%,水分利用效率分别提高15.9%和15.1%,且两处理无显著差异。因此认为,与本试验相似环境条件下,宜在秸秆还田的基础上配合深松或深耕。 相似文献
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Mojiminiyi FB Dikko M Muhammad BY Ojobor PD Ajagbonna OP Okolo RU Igbokwe UV Mojiminiyi UE Fagbemi MA Bello SO Anga TJ 《Fitoterapia》2007,78(4):292-297
The present study was designed to investigate the efficacy of an aqueous calyx extract of Hibiscus sabdariffa (HS) in two forms of experimental hypertension: salt-induced and L-NAME (N(omega)-L-arginine methyl ester)-induced and in normotensive controls. The blood pressure and heart rate fell dose-dependently in both the hypertensive and normotensive rats after intravenous injection of 1-125 mg/kg of HS, suggesting that HS possesses anti-hypertensive, hypotensive and negative chronotropic effects. The fall in mean arterial pressure was significantly pronounced in the hypertensive rats (salt-induced: 94.4+/-8.6 mm Hg; L-NAME-induced: 136.5+/-10.3 mm Hg) than in the normotensive controls (50.2+/-5.1 mm Hg; P<0.05). 相似文献
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P Gilch F Pollinger-Dammer C Musewald ME Michel-Beyerle UE Steiner 《Science (New York, N.Y.)》1998,281(5379):982-984
The recombination dynamics of a transition metal redox system monitored by femtosecond pump-probe spectroscopy are shown to be sensitive to high magnetic fields at times shorter than 10 picoseconds. The effect, based on coherent population beats of different spin states, is quantitatively accounted for and allows direct access to spin relaxation rates far beyond the time resolution of the fastest electron paramagnetic resonance technique. The presence of this ultrafast magnetic field effect helps in understanding complex reaction schemes in transition metal chemistry, which occur in a wide range of fields, such as bioinorganic chemistry and catalysis. 相似文献
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