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利用DPA使Tb3+的荧先强度显著增强的原理进行带3蛋白活性的测定,方法简便、灵敏、重复性好,而且能够进行连续荧光扫描测量.应用连续荧光扫描法测定了带3蛋白介导的DPA与Cl-交换的动力学特征参数.结果表明,带3蛋白介导的DPA与Cl-的交换对DIDS非常敏感,受DIDS的强烈抑制,抑制程度大于90%;DPA由内向外转运的米氏常Km=28.1—31.2mmol/L;带3蛋白的天然底物Cl-从内侧竞争性抑制DPA向外转运,抑制常数ki=60.4±6.9mmol/L;膜内侧DPA与外侧Cl-交换的活化能,在4—25℃范围内为5.8±0.5kCal/mol25—37℃范围内为19.8±1.5kCal/mol;膜内侧DPA与外侧Cl-交换受转运介质pH(膜内外对称改变)的显著影响,pH<7.4时,交换速度显著升高.本实验证明DPA确是经带3蛋白而转运的,但转运机制可能与无机离子转运有所不同。 相似文献
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有氧运动对高胆固醇血症大鼠肝脏低密度脂蛋白受体活性调节… 总被引:3,自引:0,他引:3
本文研究了实验性在醇血症大鼠肝脏低密度脂蛋白受体(LDL-R)活性变化及有氧运动时LDL-R活性调节的影响,发现,高脂(HC)组肝组织匀浆LDL-RI自古以来生较正常对照(NC)组降低37%(P〈0.05),同时血清大醇(TC)、低密度脂收白胆固醇(LDL-C)及血清栽脂蛋白B(ApoB)均显著高于NC组(P〈0.01);高脂+运动(HE)组TC、LDL-C及ApoB均明显低于HC组,而LDL-R 相似文献
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有氧运动对高胆固醇血症大鼠肝脏低密度脂蛋白受体活性调节的影响 总被引:5,自引:0,他引:5
本文研究了实验性高胆固醇血症大鼠肝脏低密度脂蛋白受体(LDLR)活性变化及有氧运动时LDLR活性调节的影响。发现,高脂(HC)组肝组织匀浆LDLR活性较正常对照(NC)组降低37%(P<0.05),同时血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDLC)及血清载脂蛋白B(ApoB)均显著高于NC组(P<0.01);高脂+运动(HE)组TC、LDLC及ApoB均明显低于HC组,而LDLR活性则较HC组增高26%(P<0.05)。结果提示:(1)高胆固醇负荷时细胞可通过下行调节影响LDLR活性;(2)运动可能通过增加对细胞内胆固醇利用和降解,反馈作用于下行调节过程影响LDLR的合成,增加对LDLC摄取而显著改善血脂水平。 相似文献
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对青藏高原高山冰缘地区毛茛科3种特有植物的核型进行了分析。它们的核型公式(K)、染色体相对长度组成(C.R.L.)和核型不对称系数(As.K%)分别为:青藏金莲花Troliuspumilusvar.tanguticus:K(2n)=6m+8sm(2SAT)+2st,C.R.L.=4L+4M2+4M1+4S,As.K%=63.57,核型属2B型;甘青乌头Aconitumtanguticum为K(2n)=6m+10sm,C.R.L.=4L+8M1+4S,As.K%=62.54,2B型;单花翠雀花Delphiniumcandelabrumvar.monanthum为K(2n)=6m+8sm+2st,C.R.L.=4L+4M2+4M1+6S,As.K%=64.34,属3B型。经同相关近缘种核型资料比较,青藏金莲花核型不对称性和进化程度比金莲花T.chinensis低;甘青乌头的核型不对称性和进化程度在其近缘类群(乌头组Sect.Aconitum)已报道的种之内最低;单花翠雀花核型不对称性和进化水平比翠雀组(Sect.Delphinastrum)已报道的展毛翠雀花D.kamaoensevar.glabrescens、 相似文献
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中国林蛙乳酸脱氢酶多基因系统及基因间连锁关系的研究 总被引:4,自引:0,他引:4
(1)用聚丙烯酰胺凝胶电泳对山西产中国林蛙4个地理群的333只林蛙进行了分析,结果表明:中国林蛙的LDH由LDH-A,LDH-B和LDH-C3个基因决定。LDH-A是单态座位,LDH-B和LDH-C均为多态座位,每个多态座位均有两个等位基因。LDH-B与LDH-C呈紧密连锁关系。认为LDH-C是LDH-B的重复产物。(2)热稳定性、尿素处理稳定性及组织特异性研究表明:LDH对温度和尿素处理稳定性顺序为A4>B’4>B4>C4。A4在骨骼肌和肝脏等组织中活力最大,B4在心肌和卵巢中活力最强,LDH-C主要在眼球和卵巢中表达。(3)Ldh-b和Ldh-b'在不同地理群间呈差异分布,随着纬度的增高,Ldh-b在种群中的频率增大。 相似文献
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HDL受体和肝性脂酶在肝选择性摄取HDL_2-CE中的协同作用 总被引:2,自引:0,他引:2
体外重组3H-CE-无ApoE-HDL2(rHDL2)保持天然HDL2生物活性。大鼠肝窦状隙细胞与rHDL237℃培养3h(正常组);细胞内吞cpm为995±147(x±S.D.,n=2)。细胞进一步97℃培养2h.释放三氯醋酸(TCA)沉淀和TCA上清液中cpm为78±32和12±9。N-乙酰咪唑修饰组为339±62、19±11和9±5。肝素处理组为542±78、34±14和9±8。实验结果提示:(1)肝窦状隙细胞通过HDL受体内吞HDL2摄取HDL2-CE,并通过逆向胞饮将HDL3排出体外.(2)肝性脂酶(HL)直接介导细胞选择性摄取HDL2-CE,导致HDL3生成.(3)HL和HDL受体在介导细胞选择性摄取HDL2-CE中具有协同作用。 相似文献
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渗透胁迫下玉米幼叶延伸生长与生长部位质膜H~+─ATPase的关系 总被引:3,自引:1,他引:2
-0.4MPa和-0.8MPaPEG6000对玉米幼叶延伸生长和生长部位H+分泌有明显的抑制作用,但对生长部位PMH+-ATPase则有不同程度的激活作用,正常水分条件下,Na3VO4和DCCD强烈抑制LER和H+分泌,抑制程度DCCD>Na3VO4,二者使膜透性增加的程度很相近。-0.4MPa PEG胁迫下,Na3VO4对LER和H+分泌的抑制作用不明显,而DCCD仍显著抑制LER和H+分泌;DCCD促进膜透性增加的程度远大于Na3VO4。 相似文献
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本实验以酶组织化学方法(SDH、LDH、ACP、ALP)探讨硒对氟引起肾脏损害的拮抗作用。大鼠分为六组,A组常规饮水;B组饮水含亚硒酸钠2mg/L;C组饮水中含氟化钠150mg/L;D、E、F组饮水中分别含氟化钠150mg/L,依次含亚硒酸钠0.5mg/L、2mg/L、4mg/L。8周后断头处死,观察肾脏组织中SDH、LDH、ACP、ALP的活性。结果表明,与A组相比,C组近曲小管SDH、ALP活性减弱,LDH、ACP活性明显增加;B组SDH、ACP活性正常,基底膜清晰;D、E、F组均能提高SDH活性,其中E组较稳定;F组ACP活性较高。结果说明了氟引起肾近曲小管溶酶体的破坏,而硒(2mg/L)能稳定溶酶体膜,拮抗氟对肾脏的损害作用 相似文献
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There is a notable discrepancy between the FAS (fatty acid synthase) activity of four types of fowl (egg chicken, meat chicken, egg duck, and meat duck) with distinctively different body fat levels. There is a 14.8 fold difference per unit body weight between the maximum and minimum FAS activities. The three major factors affecting this discrepancy are liver weight per unit body weight, which is 2.3 times greater in meat ducks than in egg chickens, the amount of FAS protein per gram of liver, which is 1.85 times greater in meat ducks than in egg chickens, and the FAS specific activity in meat ducks, which is 3.5 times greater in meat ducks than in egg chickens. Within the same species of egg chickens, the abdomen fat per kg of body weight at 470 days after egg production is 66 times greater than 90 days before egg production and the liver FAS activity is increased 9.6 fold. The 9.6 fold FAS activity increase resulted from an increase in the specific activity, since the liver weight per kilogram of body weight remained constant at approx. 20 grams and the FAS weight per gram of liver also remained constant at approx. 4.5 mg. This shows that the control of the basic FAS activity level which is closely related to the level of body fat does not mainly arise from genetic control. For the same kind of fowl, the control of the basic FAS activity level occurs after gene expression. It is suggested that control may be imposed in the folding phase when new peptides give rise to functional proteins. 相似文献
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Jan Ole Kriegs Andreas Matzke Gennady Churakov Andrej Kuritzin Gerald Mayr Jürgen Brosius Jürgen Schmitz 《BMC evolutionary biology》2007,7(1):190
Background
The phylogenetic tree of Galliformes (gamebirds, including megapodes, currassows, guinea fowl, New and Old World quails, chicken, pheasants, grouse, and turkeys) has been considerably remodeled over the last decades as new data and analytical methods became available. Analyzing presence/absence patterns of retroposed elements avoids the problems of homoplastic characters inherent in other methodologies. In gamebirds, chicken repeats 1 (CR1) are the most prevalent retroposed elements, but little is known about the activity of their various subtypes over time. Ascertaining the fixation patterns of CR1 elements would help unravel the phylogeny of gamebirds and other poorly resolved avian clades. 相似文献14.
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Liukkonen-Anttila T Honkanen H Peltokangas P Pelkonen O Hohtola E 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2003,134(1):69-77
We examined hepatic cytochrome P450 activity in wild and hand-reared grey partridges (Perdix perdix), capercaillies (Tetrao urogallus) and ring-necked pheasants (Phasianus colchicus), as well as the enzyme activity in a variety of tissues of hand-reared Japanese quails (Coturnix coturnix japonica) and pigeons (Columba livia). Post-mortem decrease in hepatic enzyme activity in the grey partridge was measured. Hepatic 7-ethoxyresorufin-O-deethylase activity was similar in wild and hand-reared grey partridges and pheasants, but the activity was significantly lower in wild than in hand-reared capercaillies, probably resulting from their phenolic-rich diet. In the tissues of both quails and pigeons 7-ethoxycoumarin-O-deethylase exhibited the highest and 7-pentoxyresorufin-O-deethylase the lowest activity. Hepatic enzyme activity was significantly higher than that in other tissues. In the small intestine some activity could be found, reflecting some intestinal detoxication capacity. Enzyme activity decreased by 34-69% during the 30-min sampling period, which confirmed the importance of equalising sampling time to obtain comparable data. Because the hand-reared birds in this study were fed the same commercial diets, we assumed that the enzyme activity values detected reflect species differences without any induction by dietary secondary compounds. 相似文献
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Yoshihito Shirai Takayuki Sugimoto Masayuki Hashimoto Kazuhiro Nakanishi Ryuichi Matsuno 《Bioscience, biotechnology, and biochemistry》2013,77(9):2359-2366
Two mechanisms of ice crystal growth were found in a batch crystallizer with an external cooler, that contained a large amount of ice crystals. With the first mechanism, the ice crystals grew larger by the usual kind of growth, governed by heat or mass transfer resistance, and with the second, the ice crystals agglomerated and the agglomerate fused into a very large ice crystal (1 ~3mm in diameter). The conditions in which the second mechanism prevails were investigated extensively. The second mechanism occurred not because of the high concentration of ice crystals in the crystallizer but because of long residence time. Large ice crystal agglomerates were not produced when extremely small ice crystals were formed in the crystallizer at the start of the experiment. 相似文献
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泰和鸡肾小球旁器的观察 总被引:1,自引:0,他引:1
本文用光镜和透射电镜对泰和鸡(乌骨鸡)的肾小球旁器进行了观察。结果表明,泰和鸡的肾小球旁器由球旁细胞、过渡型致密斑、球外间膜细胞和极周细胞所组成。极周细胞在鸟类还属首次报道,它位于肾小囊脏层与壁层上皮移行处,环绕着肾小体的血管极,其结构与哺乳动物的相似。本文还就泰和鸡肾小球旁器的结构与功能的关系作了讨论。 相似文献
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Transformation of macrophages into foam cells in vitro induced by cholesteryl oleate liquid crystals
Transformation of macrophages into foam cells after the uptake of cholesteryl oleate anisotropic liquid crystals was studied. A new technique to enhance the uptake of the liquid crystals by macrophages using an inverted petri dish was developed. Uptake of lipid droplets was found to increase in parallel with the amount of liquid crystals in the medium. A lysosomal enzyme was shown (by using lysosomotropic chloroquine) to be involved in the hydrolysis of the liquid crystals. About 47 and 72% of the [3H]cholesterol in liquid crystal-laden cells had disappeared after chase for 24 and 48 h, respectively. Thus the 50% clearance time of the liquid crystals by the macrophages was about 24 h, which was longer than that of denatured lipoprotein. A possible model of transformation of macrophages to foam cells is discussed. 相似文献
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Karadas F Wood NA Surai PF Sparks NH 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2005,140(4):506-511
The aim of this study was to evaluate carotenoid and vitamin E distribution in egg and tissues of newly hatched chicks from wild mallard (Anas platyrhynchos), game pheasant (Phasianus colchicus), free-range guinea fowl (Numida meleagris), hen (Gallus domesticus) and domestic duck (Anas platyrhynchos) and intensively housed hens. Carotenoid concentrations in the egg yolk of free-range guinea fowl, pheasant and wild mallard were similar (61.3-79.2 microg/g). Egg yolks from ducks and intensively housed hens were characterised by the lowest carotenoid concentration comprising 11.2-14.8 microg/g. However, carotenoid concentration in eggs from free-range ducks and hens was less than half of that in free-range guinea fowl or pheasant. Depending on carotenoid concentration in the livers of species studied could be placed in the following descending order: free living pheasant>free-range guinea fowl>free-range hen>intensively housed hen>wild mallard>housed duck>free-range duck. The carotenoid concentrations in other tissues of free-range guinea fowl and pheasant were substantially higher than in the other species studied. Egg yolk of housed hens was characterised by the highest alpha- and gamma-tocopherol concentrations. In accordance with the alpha-tocopherol concentration in the egg yolk, the birds can be placed in the following descending order: intensively housed hen>wild mallard>free-living pheasant>free-range duck>free-range hen=free-range guinea fowl>housed duck. The main finding of this work is species- and tissue-specific differences in carotenoid and vitamin E distribution in the various avian species studied. 相似文献
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Karin Nuernberg Jaroslav Slamecka Jozef Mojto Jozef Gasparik Gerd Nuernberg 《European Journal of Wildlife Research》2011,57(4):795-803
The aim of this investigation was to characterise the fatty acid composition within intramuscular fat (IMF) of two muscles
(breast and thigh) from 28 pheasants, ten wild ducks and 27 black coots from Slovakia. A high variability for all single fatty
acids (FA) and the total fat concentration in muscles of wild birds was identified. Black coots deposited the highest fat
in breast muscle whereas wild ducks and pheasants accumulated more lipids in thigh muscle. In general, the content of polyunsaturated
fatty acids (PUFA) of the IMF in wild bird muscles was high, and the saturated FA concentration was lower compared with muscles
of domestic farm animals. The ratio between PUFA and saturated fatty acids (PSQ) ranked between 0.6 and 1.2, and the ratio
of n-6/n-3 fatty acid was favourably low in black coot and wild pheasants (3.2 and 2.9, respectively). Farmed pheasants had increased
IMF and more saturated and n-6 fatty acids deposited in thigh muscle but not in breast muscle. 相似文献