不同日粮蛋白水平对昆明小鼠仔鼠断奶前生长发育的影响

分别给5组昆明小鼠雌鼠14%、16%、18%、20%和22%蛋白水平的日粮后配种。测定其产仔数、仔鼠初生重,每隔两日称重至3周龄断奶,然后采用生长曲线方程拟合生长曲线。根据所获得的参数计算相对生长率,拟合相对生长曲线。结果表明:Gompertz 方程能够很好地拟合仔鼠断奶前的生长发育过程。通过分析蛋白水平对参数估计值、累积生长曲线、相对生长率、相对生长曲线的影响,表明14%蛋白水平显著影响仔鼠的生长发育,妊娠和哺乳期昆明小鼠的蛋白质需要为18%。     

硝酸盐水平对芹菜幼苗生理及生长特性的影响

以西芹‘文图拉’幼苗为试材,通过水培方式研究了不同浓度NO3-(0、1、5、10、15、50、100、150mmol·L-1)对芹菜植株生物量、养分含量、叶绿素、丙二醛(MDA)及两种渗透调节剂含量的影响。结果显示:(1)随着NO3-浓度的增加(1～50mmol·L-1),芹菜株高、生物产量、根冠比以及叶面积显著增加,植株对N、P、K养分的吸收和叶绿素明显提高,同时植株的MDA含量上升,POD和CAT的活性增强,可溶性糖和可溶性蛋白含量显著增加。(2)当NO3-浓度等于或大于100mmol·L-1时,芹菜的生物产量和叶绿素含量下降,植株对K、P养分的吸收降低,膜脂过氧化物MDA、可溶性糖和可溶性蛋白含量及SOD活性达到最高峰值,POD和CAT活性有所下降。研究表明,NO3-浓度为15mmol·L-1时最有利于芹菜植株的生长;NO3-浓度为100mmol·L-1时对植株生长产生了硝酸盐胁迫,导致膜脂过氧化伤害,但芹菜植株能通过调节抗氧化物酶活性及渗透调节剂的合成代谢抵御环境胁迫,从而表现出一定的硝酸盐耐受性。     

低浓度84消毒液对小鼠生殖生理的影响

目的：观察低浓度84消毒液对小鼠生殖生理的影响。方法将72只KM小鼠随机分为3组,即：0.5％84消毒液组（ A组）、2.0％84消毒液组（ B组）和生理盐水组（ C组）,每组24只,雌雄各半,各组每天1次灌胃给予相应药物,连续9周。阴道涂片镜检观察雌性小鼠的动情周期。9周后,观察雄性小鼠的精子畸形率;并用ELISA法测定小鼠血清中性激素的水平;并取睾丸（或卵巢）、心、肝、肺、肾进行组织学观察。结果与C组比较,A和B组小鼠体重差异无显著性（ P ＞0.05）;血清性激素水平差异无显著性（ P ＞0.05）;雌性小鼠动情周期差异无显著性（P ＞0.05）;组织学观察未见异常;与C组比较,A组小鼠精子畸形率差异无显著性（P ＞0.05）,B组小鼠精子畸形率显著增高（ P ＝0.041＜0.05）。结论0.5％84消毒液对小鼠的生殖生理无明显影响,在实际使用中要严格控制消毒液浓度。     

土壤水分和磷营养对小麦根系生长生理特性的影响

采用小偃６号小麦品种,在模拟田间原状土容重的条件下土培,研究了土壤水分和磷营养对小麦根系生长生理特性的效应。结果表明：在土壤相对含水量为４０％─７０％范围内,土壤水分亏缺,小麦根系生长受到限制,根系比表面积（ＲＡ）、根呼吸速率（Ｒｐ）、根水势（Ｒψｗ）和叶片蒸腾强度（ＥＩ）明显降低,根系干物重（ＲＤＷ）减少;轻度干旱有利于根系的延伸生长;在土壤干旱条件下,磷营养可以提高根系ＲＡ,降低根系Ｒｐ,提高Ｒψｗ、增加叶面ＥＩ,促进根系延伸生长,扩大小麦根系对土壤深层水分的吸收和利用,进而促进地下部生长,提高ＲＤＷ。磷除作为一种营养物质促进作物根系生长发育外,在水分胁迫条件下,磷营养可明显改善植株体内的水分关系,增强对干旱缺水环境的适应能力,提高作物抗旱性。促进根系生长,提高水分利用的有效方法是根据土壤水分状况调节磷的用量。     

不同光质对烟草组培苗生长及生理特性的影响

以‘云烟87号’生根组培苗为试材,以荧光灯为对照(CK),采用LED光源发射的单色光谱红光(R)、蓝光(B)、绿光(G)等不同光质配比组合光照处理,研究光质对烟草组培苗生长和生理特性的影响。结果显示:(1)与CK相比,红蓝绿(RBG)和红蓝白(RBW)组合光质使烟草组培苗植株株高、叶长、叶宽、叶面积、茎粗、根数、根长和干重显著增加,植株叶绿素含量也有提高但差异不显著。(2)RBW组合光质照射的植株可溶性糖含量和C/N比值显著高于其他光质处理,RBG组合光质处理植株的游离氨基酸含量显著高于其他光质处理,且各光质及其组合处理的烟草叶片可溶性蛋白含量显著高于对照,红蓝配光(1RB)使植株可溶性淀粉含量较对照显著提高。(3)各光质及其组合处理的烟草膜脂过氧化物MDA含量较对照均显著降低,而其SOD、POD和CAT活性较对照均显著提高;其中红光处理的植株膜脂过氧化物MDA含量最低,CAT活性最高。研究表明,LED光源不同光质及其组合光照均能够显著降低烟草组培苗的MDA含量,降低膜脂过氧化的伤害,促进烟草组培苗的生长,其主要通过调节抗氧化物酶活性的合成代谢来应对光氧化胁迫;LED光源的RBG和RBW组合光质可作为烟草组培苗生根阶段的最适光质。     

Fmr1基因敲除对小鼠生理发育和繁殖性能的影响

目的对清洁级FVB.KO和FVB的生理发育指标和繁殖性能进行分析比较,探讨Fmr1基因敲除对小鼠生理发育和繁殖性能的影响。方法挑选10周龄清洁级FVB.KO和FVB各20只（雌雄各半）,采取1∶1同居,全部同胞兄妹近交繁殖,测定新生仔鼠生理发育指标和品系繁殖性能。结果 FVB.KO在耳廓分离、体毛长出、门齿萌发、眼睑开裂等生理发育指标上和FVB比较接近,在平均每窝产仔数和离乳率等方面偏低,在雌雄比例上有显著差异。结论 Fmr1基因敲除对小鼠生理发育和繁殖性能影响较小,对后代雌雄比例可能有一定的影响。     

氮磷钾营养水平对观赏向日葵生长发育及光合特性的影响

以观赏向日葵品种'富阳'为材料,采用3因素3水平的盆栽正交试验研究了氮磷钾用量配比对向日葵生长发育及光合作用的影响,以筛选最适宜的营养液配方.结果显示:在试验条件下,氮对观赏向日葵营养生长影响最大,尤其对株高有显著影响;磷对其生殖生长有显著影响,在120 mg/L磷水平下最早进入开花期;钾对其生长无显著影响.氮对观赏向日葵光合特性的影响最大,对净光合速率、胞间CO2浓度、蒸腾速率、气孔限制值的影响均达到显著水平,在试验条件下以280 mg/L氮施用量促进作用最为明显;磷对向日葵叶片光合参数无显著影响;钾对叶片气孔导度、叶绿素a、叶绿素总量影响显著,并以200 mg/L钾水平最为明显.研究表明,氮、磷、钾营养合理配施能有效改善观赏向日葵光合特性,提高光合速率,本试验条件下促进观赏向日葵生长发育及光合效率的最佳氮、磷、钾配比为N3:P2:K2＝14:3:10.     

氮磷营养对夏玉米水分敏感性及生理参数的影响

依据盆栽试验数据,采用Jenson模式,研究了黄土区夏玉米的水分模型。结果表明,玉米在拔节—抽穗期和抽穗—灌浆期对缺水最敏感,拔节前和灌浆—成熟期敏感性小;较高肥力水平使需水关键期水分敏感性指数增加相对较多,而在非水分关键期增加较少。较高的N、P水平增大了玉米叶片的光合速率,中度干旱条件下,N、P肥对Pn的增加幅度大于充分供水时的增加幅度;施用N、P增加了玉米叶片的蒸腾速率,但土壤水分条件影响了N、P对蒸腾速率的作用;施用N、P肥可以提高玉米的单叶WUE,随水分条件的改善而增加。高N处理的玉米根重均低于相应的低N处理,施P对玉米根系生长有明显的促进作用,中度干旱条件下的增幅大于充分供水时的增幅;不同施P处理玉米地上生物量的增幅明显大于不同施N处理的增幅;随水分条件的改善,玉米的根冠比增加,不同水分条件下施N均降低了根冠比,而施P增加了根冠比。     

不同生态稻区覆膜旱作稻氮营养生理及抗逆生理特性探讨

不同生态稻区生态环境和栽培管理方式不同,覆膜旱作稻氮营养生理和抗逆生理与常规水作稻有些异同,尤其是体内NO₃^--N和NH₄⁺-N含量及分布差异很大.杭嘉湖平原区覆膜旱作稻生长前期受干热天气影响,其分蘖期、拔节期、孕穗期体内NO₃^--N含量较水作稻有不同程度的降低,而NH₄⁺-N含量则极显著提高;金衢盆地覆膜旱作稻孕穗期体内NO₃^--N含量比常规水作稻高,根部NH₄⁺-N含量则显著降低,茎基部和叶片NH₄⁺-N含量有一定增加.正常气候条件下两生态稻区覆膜旱作稻孕穗期叶片硝酸还原酶(NR)活性和谷氨酰胺合成酶(GS)活性较水作稻均有不同程度的提高;丙二醛(MDA)、可溶性糖及脯氨酸(Pro)含量与水作稻相差不大,表明不同生态稻区的覆膜旱作稻可以通过不同的栽培管理模式,促进生长发育,达到高产目的.     

铝对秋茄幼苗生理特性的影响

为探讨铝对秋茄幼苗生理特性的影响,实验研究了不同浓度铝盐(0-100 mmol/L AlCl3)处理后秋茄的各种生理反应,对幼苗的生长、净光合效率、膜脂过氧化作用、游离脯氨酸含量等生理指标与胁迫程度及时间的关系作了对比研究,特别分析了高浓度(25-100 mmol/L Al3+)胁迫下,秋茄叶片和根部活性氧清除系统保护酶活性的变化趋势。研究发现,在10 mmol/L浓度以下,秋茄在生理特性上表现出对铝胁迫的最大适应性,能维持正常生命生长过程。当浓度增加至25-100 mmol/L,秋茄的生理反应较为敏感,膜脂过氧化加重,MDA含量及保护酶活性随铝浓度增加的变化趋势与其在海莲中的表现基本相似。高浓度铝胁迫的极端环境使植物体内产生过量的活性氧自由基,诱导了细胞膜系统的氧化损伤,最终导致秋茄植株衰老甚至死亡。抗氧化保护酶系统SOD、CAT、POD的协同作用,在一定时间内可以维持细胞内活性氧代谢平衡;特别是POD被激活的程度最大,且持续时间最长,可以考虑作为秋茄幼苗抗铝胁迫的生理标志。秋茄叶片和根部的游离脯氨酸含量在25和100 mmol/L Al3+胁迫下均显著增加。     

Relationship Between Plasma and Brain Large Neutral Amino Acids in Rats Fed Diets with Different Compositions at Different Times of the Day

Large neutral amino acids (LNAAs) compete with each other for carrier-mediated transport through the blood-brain barrier into the brain. The relative plasma concentration, expressed as the ratio of each LNAA to the sum of LNAAs, is considered the main regulator of brain LNAA concentrations. In order to investigate the consistency of this assumption throughout a 24-h period, we have compared the relationship of plasma LNAAs to brain LNAAs among groups of rats fed diets containing various amounts of protein (in order to obtain a wide range of plasma LNAA levels) at two different phases of the light/dark cycle (0900 and 2100 hours). The relationship between plasma and brain LNAAs was found to be dependent on both diet and the time of day. Similar plasma amino acid concentrations in the morning and in the evening contrasted with different brain concentrations. Furthermore, previous findings that brain LNAA concentrations are influenced by plasma amino acid concentrations were confirmed.     

Metabolic Effects of Arginine and Methionine Supplement on Rats Fed Excess Glycine Diets

The contents of glycogen, lipid, urea and amino acids, and some enzyme activities in plasma, liver muscle and urine were determined with rats fed 10 to 12 g of 100 g body weight per day of the 10% casein diet (control) and 10% casein diets containing 7% glycine with or without 1.4% l-arginine HC1 and l-methionine for 7 days.

Nine hours after the final feeding, the amount of liver glycogen was high in the order of rats fed 10% casein diet containing 7% glycine, 10% casein diet containing 7% glycine with l-arginine and l-methionine, and the control. The amount of muscle glycogen was decreased only in those fed the control diet. The amount of liver lipid was increased by the addition of l-arginine and l-methionine to the excess glycine diet. Plasma and urinary urea was increased in animals given the excess glycine diets with or without both amino acids. In plasma liver, and muscle of animals given either of both the excess glycine diets 3 and 9 hr after the feeding, in general, glycine and serine were increased, and threonine and alanine were decreased as compared with those of rats given the control diet. However, the increase of glycine in plasma, liver and muscle detected at 9 hr after feeding the excess glycine diet was slightly prevented by the supplementation of both amino acids to the excess glycine diet. The activities of liver glycine oxidase and ornithine δ-aminotransferase of rats given the excess glycine diet with both amino acids were higher than those of other dietary groups. Liver serine dehydratase and glutamate-oxalacetate transaminase activities were high in the order of the animals fed the control, the excess glycine diet and the excess glycine diet containing both amino acids. Glutamate-pyruvate transaminase activity in the liver of rats fed the excess glycine diets with or without both amino acids were markedly higher than that of those fed the control. The activities of phosphopyruvate carboxylase and aconitase in the liver of animals given the excess glycine diet were higher than those of other dietary groups. Liver pyruvate kinase and glutamate dehydrogenase activities were similar among those dietary groups.     

Sterol/steroid metabolism and absorption in a generalist and specialist caterpillar: Effects of dietary sterol/steroid structure,mixture and ratio

Insects cannot synthesize sterols de novo, so they typically require a dietary source. Cholesterol is the dominant sterol in most insects, but because plants contain only small amounts of cholesterol, plant-feeding insects generate most of their cholesterol by metabolizing plant sterols. Plants almost always contain mixtures of different sterols, but some are not readily metabolized to cholesterol. Here we explore, in two separate experiments, how dietary phytosterols and phytosteroids, in different mixtures, ratios, and amounts, affect insect herbivore sterol/steroid metabolism and absorption; we use two caterpillars species – one a generalist (Heliothis virescens), the other a specialist (Manduca sexta). In our first experiment caterpillars were reared on two tobacco lines – one expressing a typical phystosterol profile, the other expressing high amounts/ratios of stanols and 3-ketosteroids. Caterpillars reared on the control tobacco contained mostly cholesterol, but those reared on the modified tobacco had reduced amounts of cholesterol, and lower total sterol/steroid body profiles. In our second experiment, caterpillars were reared on artificial diets containing known amounts of cholesterol, stigmasterol, cholestanol and/or cholestanone, either singly or in various combinations and ratios. Cholesterol and stigmasterol-reared moths were mostly cholesterol, while cholestanol-reared moths were mostly cholestanol. Moth tissue cholesterol concentration tended to decrease as the ratio of dietary cholestanol and/or cholestanone increased. In both moths cholestanone was metabolized into cholestanol and epicholestanol. Interestingly, M. sexta generated much more cholestanol than epicholestanol, while H. virescens did the opposite. Finally, total tissue steroid levels were significantly reduced in moths reared on diets containing very high levels of cholestanol. We discuss how dietary sterol/steroid structural differences are important with respect to sterol/steroid metabolism and uptake, including species-specific differences.     

Effects of Different Ratios of Mixture of Starch and Casein,or Starch and Fat,in Diets on Lipogenesis in Rats

Studies were made on the incorporation of ¹⁴C of acetate-1-¹⁴C into the lipids of the liver and carcass, and changes in the concentrations of nucleotides, citric acid, and free fatty acids in the liver, using rats fed diets consisting of starch and casein, or starch and corn oil, at different ratios. Lipogenesis was stimulated with an increase in the content of starch both in the starch-casein and starch-corn oil diets. There was a rapid drop in lipogenesis in rats fed the diet with a little increment in the content of corn oil. Lipogenesis decreased gradually with an increment in the content of casein in the starch-casein diet. A positive correlation was found between lipogenesis and the level of ATP in the liver. The concentration of citric acid decreased with an increase in lipogenesis in the liver. Changes in dietary composition did not produce any significant alteration in the concentration of free fatty acids in the liver.     

Comparison Between Different Delivery Vehicles for the Probiotic Bifidobacterium animalis subsp. lactis HN019 on Experimental Periodontitis in Rats

This study aimed to assess the effects of the probiotic (PROB) Bifidobacterium animalis subsp. lactis HN019 in two different delivery vehicles in experimental periodontitis (EP), including the gene expression for IL-10, IFN-γ, and FOXP3. In total, 32 rats were assigned into groups (n=8): C (control), EP, EP-PROB/Water, and EP-PROB/Milk. The probiotic was administered for 4 weeks, from baseline to euthanasia. Periodontitis was induced by ligatures 14 days after baseline. Data were statistically analyzed (p<0.05). Both probiotic groups presented decreased alveolar bone loss and increased interproximal attachment level than group EP. Also, these parameters were significantly improved in the Milk group when compared with the Water group. EP-PROB/Milk showed higher gene expression for IL-10 and lower for FOXP3 in relation to EP-PROB/Water and EP groups. The use of milk was able to potentiate the protective effects of B. lactis HN019 in rats under EP.

     

Effects of Arginine and Methionine on the Growth Depression of Rats Fed Diets High in Glycine

In order to determine if the growth retardation by dietary exceess glycine could be prevented by the addition of arginine and/or methionine, weanling rats were fed a 25% casein diet (standard) or a 10% casein diet (low protein diet) with a supplement of several combinations of glycine, arginine, or methionine.

The changes in body weight, urinary creatinine, and kidney transamidinase activity were determined. The growth depression effect by excess glycine was prevented considerably in animals receiving standard diet and completely in animals receiving low protein diet by the addition of arginine and methionine to the high glycine diets.

The total urinary creatinine was increased by the supplement of both glycine and arginine, while the growth rate was not invariably raised and kidney transamidinase activity had a tendency to decrease.     

Effects of Linalool on Glutamate Release and Uptake in Mouse Cortical Synaptosomes

Linalool, a monoterpene compound prevalent in essential oil of plant species traditionally used as sedatives, has been characterized as anticonvulsant in several experimental models. Linalool inhibits the binding of [³H]glutamate and [³H]dizocilpine to brain cortical membranes, indicating a participation of the glutamatergic transmission its mechanism of action. In this study, we investigated the effects of linalool on [³H]glutamate release (basal and potassium-stimulated) and [³H]glutamate uptake in mice cortical synaptosomes. Linalool significantly reduced potassium-stimulated glutamate release as well as glutamate uptake, not interfering with basal glutamate release. The data indicates that linalool may interfere with several relevant elements of the glutamatergic transmission, including detriment of the K⁺-stimulated glutamate release.     

不同剂量链脲菌素对恒河猴某些常规生理指标的影响

目的　研究链脲菌素 (STZ)对恒河猴摄食、饮水、排尿、体重、血糖及尿糖等生理指标的影响 ,为建立糖尿病动物模型积累资料。方法　通过静脉给 7只恒河猴注射不同剂量的STZ。结果　使用不同剂量STZ后 ,7只恒河猴均在不同时间、不同程度出现与人糖尿病相类似的“三多一少”症状 ,同时对糖尿病猴使用不同剂量胰岛素可使其症状减轻。尤其是中、高剂量组的动物症状较为明显 ,而低剂量组体重有一个短时间的增加后又迅速下降。实验组中血糖和尿糖均出现不同程度的升高 ,以中、高 2个剂量组的动物变化较大。结论　采用中、高剂量组的STZ可诱导类似人类糖尿病的急性动物模型 ,而使用胰岛素治疗或低剂量STZ可使该动物模型疾病病程延长 ,有利于进行其并发症的研究。     

Effects of Nano-zinc on Biochemical Parameters in Cadmium-Exposed Rats

Cadmium (Cd) is a toxic environmental and occupational pollutant with reported toxic effects on the kidneys, liver, lungs, bones, and the immunity system. Based on its physicochemical similarity to cadmium, zinc (Zn) shows protective effects against cadmium toxicity and cadmium accumulation in the body. Nano-zinc and nano-zinc oxide (ZnO), recently used in foods and pharmaceutical products, can release a great amount of Zn²⁺ in their environment. This research was carried out to investigate the more potent properties of the metal zinc among sub-acute cadmium intoxicated rats. Seventy-five male Wistar rats were caged in 15 groups. Cadmium chloride (CdCl₂) was used in drinking water to induce cadmium toxicity. Different sizes (15, 20, and 30 nm) and doses of nano-zinc particles (3, 10, 100 mg/kg body weight [bw]) were administered solely and simultaneously with CdCl₂ (2–5 mg/kg bw) for 28 days. The experimental animals were decapitated, and the biochemical biomarkers (enzymatic and non-enzymatic) were determined in their serum after oral exposure to nano-zinc and cadmium. Statistical analysis was carried out with a one-way ANOVA and t test. P < 0.05 was considered as statistically significant. The haematocrit (HCT) significantly increased and blood coagulation time significantly reduced in the nano-zinc-treated rats. AST, ALT, triglyceride, total cholesterol, LDL, and free fatty acids increased significantly in the cadmium- and nano-zinc-treated rats compared with the controls. However, albumin, total protein, and HDLc significantly decreased in the cadmium- and nano-zinc-treated rats compared with the controls (P < 0.05). It seems that in the oral administration of nano-zinc, the smaller sizes with low doses and the larger sizes with high doses are more toxic than metallic zinc. In a few cases, an inverse dose-dependent relationship was seen as well. This research showed that in spite of larger sizes of zinc, smaller sizes of nano-zinc particles are not suitable for protection against cadmium intoxication.