~(32)P的吸收、转运与甘蓝型油菜抗菌核病性的关系

用32P示踪法研究了不同抗性油菜品种3叶期及盛花期感染菌核病后磷素吸收与转运的变化。研究结果表明:磷素向着生长旺盛部位转运;接种后植株磷素吸收增强而且磷素向着接种叶富集,感病品种甚于抗病品种;经相关性分析,第2位叶(接种叶)、第3位叶磷素放射性活度提高幅度显著且与抗性成显著或极显著负相关。这说明磷素的吸收、转运与抗性有密切的关系。在盛花期,花果中磷素放射性活度呈上升趋势,宁RS-1和宁油7号叶中的磷素放射性活度都先上升后下降,但前者上升的幅度较大,而且后期下降缓慢;宁油7号茎中的磷素放射性活度呈稳定下降趋势,而宁RS-1表现为先上升后又下降。这说明抗病材料有较强的生理活性来抵抗病害。     

暗处理和钾营养对水稻~(14)CO_2同化及其产物输出的影响

在两种钾水平下,研究了暗处理对缺钾敏感品种的~(14)CO_2同化及同化产物输出的影响。结果表明,经暗处理后,水稻植株对CO_2的固定,孕穗期在两种钾水平下均明显下降;灌浆期低钾植株CO_2固定明显降低。常量钾处理的标记植株的总放射性活度高于低钾处理的植株,并随暗处理时间的缩短而增加,光与钾有助于光合产物向谷粒中分布。叶片中糖含量,灌浆期多于孕穗期。在自然光照下,常量钾植株的含糖量多于低钾处理,暗处理则低钾多于常量钾处理。叶片中ATP含量,在正常光照与暗处理下低钾处理均高于常量钾处理。暗处理与人工24小时光照使标记叶光合产物的输出量减少,而钾营养则促进光合产物的输出。     

The Physiological Mechanism of Postphloem Sugar Transport in Citrus Fruit

The dynamics of translocation and partitioning of 14C-phothsynthates, the concentration of sucrose in fruit tissues and the effects of the membrane carrier- and ATPase-specific inhibitors on 14C-sucrose uptake by juice sacs of the satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit were examined at the stage of fruit enlargement and fruit full ripe. Kinetic data of 14C-photosynthate translocation indicated that the rate of photosynthate transport into juice sacs decreased with fruit maturation and sugar accumulation. Along the photosynthate translocation path, i.e. from vascular bundles to segment epidermis then to juice sacs, a descending sugar gradient was observed. With fruit maturation and sugar accumulation in juice sacs, the 14C photosynthate gradient increased, whereas the static sucrose concentration gradient decreased with fruit maturation and sugar accumulation. The higher gradient of specific 14C radioactivity was considered to favor diffusion and sugar transport into juice sacs at the later stage of fruit development. The rate of uptake 14C-sucrose by juice sacs of satsuma mandarin fruit was markedly reduced by PCMBS, EB, DNP and NO-3 treatment. The above results suggested the participation of a carrier-mediated, energy-dependent sugar active transport process in juice sacs of satsuma mandarin fruit.     

Transneuronal transfer of radioactivity in the central nervous system

After injection of tritiated amino acid into the mouse eye, radioactivity appeared in the contralateral visual cortex, indicating that some material had been transferred from optic axons to lateral geniculate neurons. The radioactivity in the cortex was about 2 percent of that arriving in the geniculate, and most of it was contained in material that appeared to be protein.     

Insulin biosynthesis: evidence for a precursor

Human islet cell tumor tissue and isolated islets of Langerhans from rats incorporated radioactive amino acids in vitro into insulin and a larger acid-alcohol soluble protein which could be separated from insulin by gel filtration. The amino acids were incorporated into the larger protein earlier than into insulin; only after incubation of islets for approximately 30 minutes did radioactivity begin to appear in insulin. The transfer of about 70 percent of the radioactivity of the larger protein to insulin was demonstrated in the absence of new peptide bond synthesis (cycloheximide), or during incubation with unlabeled amino acid (chase). The results indicate that the larger protein is a precursor in the biosynthesis of insulin. The name "proinsulin" is suggested for this protein.     

Rat brain binds adrenal steroid hormone: radioautography of hippocampus with corticosterone

Tritiated corticosterone injected subcutaneously into adrenalectomized male rats 1 hour before killing produced intense labeling of the hippocampus in radioautograms prepared by a method that reduced or prevented diffusion of the radioactive material. The pyramidal neurons of the cornu ammonis and the granule neurons of the gyrus dentatus contained more radioactivity than did other regions of the brain; however, the intensity of labeling varied among adjacent neurons. The nuclei of many neurons were clearly labeled but radioactivity was relatively sparse in the cytoplasm, in the axons where they branch from cell bodies, and in adjacent neuropil.     

柑橘果实韧皮部后糖的运输生理机制研究

 以膨大期和完熟期的温州蜜柑宫川 (CitrusunshiuMarc .cv .Miyagawawase)果实为试材 ,研究了14C光合产物在果实内的运输分配动态 ,测定了果实各组织的蔗糖浓度 ,分析了载体和ATP酶抑制剂对汁囊吸收14C 蔗糖的影响。结果表明 ,光合产物运入汁囊积累的速率随着果实成熟和糖积累呈下降趋势。沿维管束到囊瓣皮再到汁囊的光合产物运输路径存在由高到低的糖梯度。其中 ,组织间运输态的14C放射性比活度的梯度随果实成熟和糖积累而加大 ,而静态的蔗糖梯度则趋缓 ,表明14C放射性比活度梯度的形成有利于后期糖积累。载体抑制剂PCMBS和ATP酶抑制剂DNP、EB、NO3- 处理明显抑制了汁囊对14C 蔗糖的吸收。由此可见 ,糖在温州蜜柑果实汁囊中的运输存在一个需要载体并与ATP酶相偶联的主动运输过程     

60Co-γ射线辐射对一品红丙二醛及几种保护酶的影响

 探讨了⁶⁰Co-γ射线辐射对一品红丙二醛及几种保护酶的影响。结果表明,SOD酶活力与POD酶活力之间呈显著正相关(R=0.656^*),SOD比活力与PPO酶活力、PPO比活力之间呈极显著负相关(R=-0.716^*,R=-0.714^*);SOD酶活力、POD酶活力以10GY辐射处理值最高,10GY辐射处理的PPO酶活力居第2,丙二醛含量及CAT酶活力居第8。因此,综合此5项生理指标的生理生化功能,一品红的此4种保护酶活力和丙二醛含量以10GY辐射处理的表现较为适中。     

Transport of protein by goldfish optic nerve fibers

After tritiated leucine was injected into the eye of goldfish, radio-active protein synthesized by the ganglion cell bodies moved down the optic axons at an average rate of 0.4 mm per day. Radioautograms of the optic tectum in which these axons end show that, as early as 24 hours after the injection, before the radioactivity in the tectal layer containing the optic axons had risen above background level, the layer containing the axon terminals was already heavily labeled. The radioactivity in the terminals reached a maximum about 48 hours after the injection and remained approximately constant for at least 23 days thereafter, whereas the radioactivity in the fiber layer increased significantly during the same interval, as the slowly moving protein component entered it. Thus there appears to be a special mechanism for rapid transport of protein from the cell body to the synaptic terminals, as well as a slower movement of protein down the axon.     

Biosynthesis of norepinephrine in isolated canine heart

Radioactive dopamine was injected into the blood that was perfusing an isolated heart preparation. Analysis of the norepinephrine obtained from the heart 1 hour later demonstrated that it contained radioactivity. Between 1.4 and 10.8 percent of the norepinephrine present had been formed from the dopamine. The turnover of norepinephrine was substantially higher in the ventricles than in the atria.     

玻璃化冷冻对猪卵母细胞体外发育能力的影响

采用猪未成熟(GV期)和体外成熟(MⅡ期)卵母细胞分组进行冷冻保护剂毒性试验,试验组经冷冻液处理,对照组不用冷冻液处理。结果表明,GV期与MⅡ期卵母细胞相比,两者经冷冻保护剂处理后,其存活率、体外受精胚卵裂率均无显著差异(P>0.05);试验组GV期卵母细胞存活率、体外成熟率及体外受精胚卵裂率虽略低于对照组(85.9%,72.4%和50.9%对91.3%,73.9%和53.3%),但差异不显著(P>0.05);试验组MⅡ期卵母细胞存活率虽显著低于对照组,但卵裂率与对照组无显著差异(P>0.05)。表明所用冷冻液及其处理程序,对卵母细胞无明显毒性。分3组对猪卵母细胞进行冷冻保存试验:I组为对照组;II组为GV期卵母细胞冷冻组;III组为MⅡ期卵母细胞冷冻组。结果表明,经开放式拉管(Open pulled straw,OPS)法玻璃化冷冻后,GV期和MⅡ期卵母细胞均获得较高的形态正常率,但GV期卵母细胞冷冻后存活率要显著高于MⅡ期卵母细胞(P<0.05)。经玻璃化冷冻后,GV期卵母细胞的体外成熟率和卵裂率均明显低于新鲜卵母细胞(42.6%和7.79%对73.9%和53.3%,P<0.05),MⅡ期卵母细胞冷冻-解冻后未获得卵裂。在GV期卵母细胞冷冻组,154枚卵母细胞冷冻后经体外成熟、体外受精及体外培养,共有12枚发生卵裂,其中6枚发育至8-细胞,3枚发育至16-细胞,3枚发育至桑椹胚。本研究表明,所用冷冻方案更适合于猪GV期卵母细胞的冷冻保存。     

6-Methylpurine-H3: intracellular localization in pea root tip cells

6-Methylpurine-H3, a potent inhibitor, was detected by autoradiography in the nucleoli of pea root tip cells. Most of the radioactivity was in the nucleoli of growing cells in the meristematic region. Treatment of the labeled cells with ribonuclease indicates that 6-methylpurine-H(3) is incorporated into nucleolar RNA which then moves from the nucleolus to the cytoplasm.     

Carbon dioxide fixation in marine invertebrates: a survey of major phyla

Fourteen species of marine invertebrates representing 12 phyla were kept in sea water containing NaHC(14)O(2) for 1 hour. All of them fixed CO(2) into acids of the Krebs citric acid cycle. In most species the major portion of the radioactivity recovered after chromatography was in succinic, fumaric, and malic acids. The findings favor the hypothesis that both CO(2) fixation and the citric acid cycle are virtually universal among marine invertebrates.     

Liposomal blockade of the reticuloendothelial system: improved tumor imaging with small unilamellar vesicles

The reticuloendothelial system of mice bearing EMT6 tumors was effectively blocked by intravenous injections of small unilamellar vesicles that incorporated a 6-aminomannose derivative of cholesterol in the lipid bilayer. Neutral liposomes loaded with indium-111-nitrilotriacetic acid were then injected. Fifty percent more radioactivity was deposited in tumors of the animals with blocked reticuloendothelial systems than in controls. Twenty-four hours after the injection of radioactive vesicles, well-defined tumor images were observed in whole-body gamma camera scintigraphs. Biodistribution studies showed that tumors from animals with blocked reticuloendothelial systems had more than twice the radioactivity per gram than any other tissue analyzed.     

60Co-γ射线辐射对芦荟生理指标的影响

探讨了6 0 Co- γ射线不同剂量辐射对芦荟生理指标的影响。试验结果表明 :淀粉以 10Gy辐射处理值最高 ,2 0Gy辐射处理最低 ;蛋白质以未辐射处理值最高 ;可溶性糖、SOD比活力、POD比活力、CAT比活力均以 2 0Gy辐射处理最高 ;PPO比活力与辐射剂量之间存在极显著正相关。芦荟的生理生化功能以 2 0Gy辐射处理的表现较为适中。     

Narcotic tolerance and dependence: lack of relationship with serotonin turnover in the brain

Serotonin turnover was measured in mouse brain by means of the conversion of radioactivity from labeled tryptophan into serotonin. Animals with a high degree of tolerance to and physical dependence on morphine did not differ from control mice.     

烤烟上部叶不同烘烤工艺应用~(32)P测定水分运输规律的研究

[目的]研究烤烟上部烟叶一次性采烤和带茎烘烤过程中水分的代谢情况。[方法]用32P同位素示踪法,研究了烤烟上部烟叶一次性采烤和带茎烘烤过程中水分代谢情况。[结果]带茎烘烤时烟茎中水分能进入烟叶中参与代谢。根据同位素示踪法对DNA、RNA中放射性的测定,发现不论是带茎烘烤还是一次性采烤各时期茎秆或叶柄的水分都参与叶片中核酸代谢。[结论]带茎烘烤时烟茎中的水分能进入烟叶中参与代谢。     

温度和光强对金钗石斛吸收磷素的影响

应用３２Ｐ研究了温度和光强对金钗石斛吸收磷素的影响。结果表明,２５℃和４０℃处理,植株吸磷量分别为１０℃处理的２．３和２．５倍。２５℃处理,茎中３２Ｐ放射性比活度最高。在中度光（２×１０４Ｌｘ）和高光强（５×１０４Ｌｘ）下,植株吸磷量分别较弱光（５×１０３Ｌｘ）下增加７４％和２３％。在中度光下,茎中３２Ｐ放射性比活度最高。     

~(95)Zr水样的测量方法研究

采用BH12 2 4型能谱仪测量了95 Zr水样的能谱图 ,并对其测量的重复性、样品量和活度对测量结果的影响等进行了测定分析 ,确定了相应的校正曲线。结果显示 :1) 95 Zr能谱有三个峰 ,选取S3峰 (2 40 30 0能谱道 )作为样品活度的测量道较为合适 ;2 )测量时间对测样的计数率没有影响 ;样品量对测样的重复性影响较小 ;3)随着样品量的增加 ,同一活度样品的测量值呈下降趋势 ,应进行该项目的校正 ,校正曲线为Y1 =1.0 183- 0 .0 0 70X1 (X1 为测样的样品量 g) ;4)仪器死时间引起的漏计数不容忽视 ,对测量结果应进行死时间校正 ,其校正系数 (% )Y2 =10 1.33- 0 .0 2 2 6X2 (X2 为测样的计数率cps) ;5 )样品活度对测量的重复性有影响 ,当测样的活度过小时 ,其重复性就较差 ;为获得较好的测量重复性 (<1% ) ,活度以大于2 0 0Bq为宜。     

Plasma protein synthesis in the liver: method for measurement of albumin formation in vivo

l-Arginine labeled with carbon-14 at the guanido group was injected into rabbits, and the ratio of the rates of entry of radioactivity into the protein and urea was determined. This ratio, multiplied by the rate of arginine utilization in urea synthesis and by the ratio of protein to protein arginine weights, gives the rate of protein synthesis. The method applies to albumin and should apply to any plasma protein synthesized in those liver cells which also synthesize urea.