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1.
本研究通过观察大鼠力竭性游泳后睾丸金属结合蛋白(TMBP)、睾酮和锌含量的动态变化,探讨TMBP的被诱导性、诱导特点以及与睾酮合成和锌代谢的关系。结果显示:大鼠力竭性游泳后,TMBP呈一过性升高,峰值在游泳后6h处,达安静时4 16倍;游后12h已降回原有水平。这表明TMBP可被力竭性游泳所诱导,并减期不至6h。TMBP诱导性的发现对认识TMBP的功能具有重要的意义。大鼠睾丸酮在力竭性游泳后即刻急  相似文献   

2.
通过观察具有不同睾丸金属结合蛋白(testismetalbindingprotein,TMBP)含量的对照和缺锌后补锌大鼠安静时和力竭性游泳后不同时间睾丸和血清睾酮和锌含量变化,以探讨TMBP含量对睾酮合成速率的影响.实验结果证实了如下推测:TMBP含量不同,睾酮合成的速率也不同,高起始含量TMBP的状况下,睾丸睾酮的合成加快.这一结果提示:TMBP可能参与睾酮的合成.  相似文献   

3.
Liu DC  Yuan YJ 《生理学报》1999,51(1):111-114
睾丸切除后,家猫前列腺背叶、腹叶及尿道球腺内的金属硫蛋白(metalothionein,MT)分别下降至正常家猫的212%(P<001)、884%(P>005)和185%(P<001),而在腹叶影响较小。睾丸切除后注射芝麻油,前列腺背叶及尿道球腺MT均未得到恢复。但若在睾丸切除后连续3d注射10μg/kgbw睾酮,两者依次恢复至693%和594%。随睾酮注射剂量增加(5、10、15、20、25μg/kgbw),血浆睾酮的浓度、前列腺背叶及尿道球腺MT含量增高。血浆睾酮与前列腺背叶及尿道球腺MT呈正相关(P<001)。这些结果表明,睾酮诱导前列腺背叶及尿道球腺MT,其最适剂量为20μg/kgbw。  相似文献   

4.
ESR研究急性运动及恢复期大鼠RBCM脂流动性的改变   总被引:2,自引:0,他引:2  
本文以大鼠递增负荷力竭性运动为模型,利用电子自旋共振(ESR)技术测定急性运动中及不同时程恢复期红细胞膜(RBCM)脂流动性的改变。RBCM脂尾部流动性在短时间中等强度运动(三级负荷末)即有明显下降(P<0.05),在运动后恢复期进行性加重,并于运动后12h达极显著改变(P<0.01):此时膜脂头部流动性也明显下降(P<0.05)。之后二者均有恢复趋势,提示递增负荷力竭性运动对RBCM脂流动性有重要影响,并且RBCM脂流动性与膜功能相互作用,互相影响  相似文献   

5.
谷氨酰胺对力竭性游泳大鼠抗氧化作用的影响   总被引:2,自引:0,他引:2  
目的:探讨谷氨酰胺(Gin)对力竭性游泳大鼠的抗氧化保护作用。方法:灌服Gin大鼠力竭游泳2h后,检测血清、肾、肝组织中丙二醛(MDA)、谷胱甘肽(GSH)和超氧化物歧化酶(SOD)含量的变化。结果:力竭性游泳大鼠血清、肝SOD显著升高,肾SOD显著下降;肾MDA含量显著增高,血清和肾GSH显著下降。补充Gin能抑制血清、肝组织SOD升高和肾组织MDA的增多。结论:Gin对力竭性游泳所致的氧化应激有一定的保护作用。  相似文献   

6.
为了研究恒河猴睾丸的激素分泌及其调节作用,作者发展了一种简便分离睾丸Leydig细胞和用无血清培养的实验模型,研究了人绒毛膜促性腺激素(hCG)、恒河猴绒毛膜促性腺激素(mCG)、环磷酸腺苷(cAMP)、Forskolin和雌二醇(E2)对睾丸Leydig细胞激素分泌的影响。结果显示离体的Leydig细胞对低剂量同源的mCG和异源的hCG产生睾酮都有依赖反应,而高剂量的前者对Leydig细胞分泌睾酮有明显的抑制作用,后者不出现反向调节;cAMP和Forskolin对Leydig细胞分泌睾酮有刺激作用;雌二醇具有明显抑制hCG和mCG促睾丸分泌的作用  相似文献   

7.
昆虫细胞色素P450研究:P450酶系的可诱导性   总被引:8,自引:1,他引:7  
细胞色素P450酶系是生物体中的一类重要的代谢酶系,它的一个重要特征是它的可诱导性[1]。自Brown等[2]发现一定的化合物可以促进MFO的活性以来,诱导现象得到深入细致地研究,并成为了解P450分子遗传学的工具[3]。诱导是指通过暂时的、加速合成产生正常水平以上的附加蛋白的现象[4]。昆虫中诱导现象的首篇报道是AgosinandDinamarca[5],他们发现施用DDT于侵扰锥猎蝽Triatomainfestans(Klng)这种吸血昆虫时,昆虫的NADP含量上升,后来Morello[6]…  相似文献   

8.
通过TIBA、LaCl3、Verapamil和TFP对菜豆下胚轴导管分化和形成的调控作用,证明生长素、Ca2+和CaM是木质部导管分化和形成所必需的。NAA能诱导菜豆下胚轴导管的分化;TIBA能抑制生长素类诱导的导管分化和形成;LaCl3和TFP在导管分化诱导期(最初24h)具抑制作用;Verapamil与TIBA相似,在导管分化诱导期和导管形成期(伤口形成后72h之内)都有抑制作用。  相似文献   

9.
本实验分别在大鼠衰竭跑后即刻、0.5、1、3及24h同时检测了血清睾酮(T)、黄体生成素、睾丸组织脂质过氧化物丙二醛和超氧化物歧化酶。结果表明,大鼠衰竭跑后恢复30min时,伴随着睾丸组织丙二醛含量的明显升高及超氧化物歧化酶活性的显著降低,血清T水平也明显降低。提示,长时间衰竭跑后血清T浓度的降低很可能与缺血-再灌引起睾丸组织氧自由基剧增及脂质过氧化损伤,从而降低了酶的活性和抑制了T的合成有关。氧自由基清除剂能减轻和预防该损伤,并能有效地防止运动后血清T的降低。  相似文献   

10.
目的初步分离和鉴定力竭运动诱导的大鼠睾丸金属结合蛋白(testis metal-binding proteins,TMB-Ps)。方法 8只雄性SD大鼠一次性力竭游泳运动(8只对照)后6 h取睾丸和肝脏组织,用镉饱和法测定TMBPs和肝脏金属硫蛋白(metallothionein,MT)含量,用tricine-SDS-PAGE方法分离镉饱和法提取液的TMBPs组分和肝脏MT,用液相色谱-串联质谱法(LC-MS-MS)鉴定TMBPs分离条带。结果力竭运动组大鼠TMBPs水平(113.71±11.72)nmol Cd/g testis显著高于安静对照组(87.14±12.72)nmol Cd/g testis(P0.01),肝脏MT表达量(64.70±14.89)μg/g也显著高于安静对照组(7.32±3.31)μg/g(P0.001)。LC-MS-MS对tricine-SDS-PAGE分离的蛋白条带的鉴定结果为:TMBPs含有泛素、铜-锌-超氧化物歧化酶、酪蛋白样磷蛋白等蛋白质,另外还应包括MT。结论TMBPs由一组具有金属结合性、耐热性和诱导性的蛋白质所组成,主要有泛素、超氧化物歧化酶和酪蛋白样磷蛋白。镉饱和法并非测定金属硫蛋白的特异性方法。  相似文献   

11.
本文测定了不同运动条件下的大鼠骨骼肌中的雄激素受体(androgenreceptor,AR)结合容量及雄激素的水平。一次力竭运动可使大鼠股四头肌组织的雄激素结合容量水平上升,但降低了其组织中的雄激素水平。在长期力竭性运动后,股四头肌组织雄激素受体结合容量及雄激素水平均没有变化,而长期的适宜运动则可提高股四头肌的雄激素结合容量的水平,但对其雄激素的水平仍无影响。通过机体注射HCG(人促绒毛膜性腺激素),可提高骨骼肌组织的雄激素水平,但骨骼肌雄激素受体结合容量水平没有变化。连续注射HCG4天,其骨骼肌组织雄激素水平显著高于连续注射HCG8天的水平。根据上述结果,我们认为,在考虑骨骼肌同化过程时,不但要注意其雄激素的水平,还应注意其雄激素受体的水平。运动对骨骼肌组织的雄激素受体结合容量及骨骼肌雄激素分布的影响是双向的  相似文献   

12.
The D-trehalose/D-maltose-binding protein (TMBP), a monomeric protein of 48 kDa, is one component of the trehalose and maltose uptake system. In the hyperthermophilic archaeon T. litoralis this is mediated by a protein-dependent ATP-binding cassette system transporter. The gene coding for a thermostable TMBP from the archaeon T. litoralis has been cloned, and the recombinant protein has been expressed in E. coli. The recombinant TMBP has been purified to homogeneity and characterized. It exhibits the same functional and structural properties as the native one. In fact, it is highly thermostable and binds both trehalose and maltose with high affinity. In this work we used differential scanning calorimetry studies together with a detailed analysis, at the molecular level, of the three-dimensional protein structure to shed light on the basis of the high thermostability exhibited by the recombinant TMBP from the archaeon T. litoralis. The obtained data suggest that the presence of trehalose does not change the overall mechanism of the denaturation of this protein but it selectively modifies the stability of the TMBP structural domains.  相似文献   

13.
We investigated the effect of temperature on the binding specificity of the recombinant d-trehalose/d-maltose-binding protein from the hyperthermophilic archaeon Thermococcus litoralis (TMBP). Importantly, we found that TMBP can bind d-glucose (Glc). The Glc binding was characterized by means of fluorescence spectroscopy in the temperature range of 25 degrees C-85 degrees C. Our results show that at 25 degrees C the binding of Glc to TMBP is well represented by a bimodal model with apparent K(d) of 20 muM and approximately 3-8 mM for the first and the second binding step, respectively. At 60 degrees C the binding of Glc to TMBP is represented by a simple hyperbolic model with an apparent K(d) value of about 40 muM. Finally, at 85 degrees C Glc did not bind to TMBP. Molecular dynamics (MD) simulations were used to shed light on the molecular mechanism of the Glc binding. Our results suggest that after proper fluorescent labeling TMBP can be used as a highly thermostable and non-consuming analyte biosensor for monitoring the level of glucose in fluids (e.g. human blood) where other sugars are not present.  相似文献   

14.
Triggering of the CD3:TCR complex by optimal concentrations of anti-CD3, anti-TCR beta-chain, and allogeneic stimulator cells induced dramatically higher levels (fivefold for anti-CD3, greater than 10-fold for anti-TCR beta-chain, 84-fold for alloantigen) of IL-2 production in spleen CD4+8- T cells than their thymic counterparts, despite comparable levels of CD3 and TCR beta-chain expression. The nature of the reduced IL-2 production was examined by analysis of anti-CD3-induced IL-2 production at the single cell level. The frequency of IL-2-producing cells in spleen CD4+8- T cells (40.0%) was approximately threefold that of thymus CD4+8- T cells (14.5%). Furthermore, the average IL-2 levels among positive IL-2 producers was also approximately threefold higher in spleen CD4+8- T cells than their thymic counterparts. Adoptive transfer of purified Thy-1.2+ CD4+8- T cells into Thy-1.1-congenic hosts provided a physiologic and histocompatible system that enabled identification of transferred donor (Thy-1.2+) among a sea of host (Thy-1.2-) CD4+ T cells, whose immune function with respect to IL-2 inducibility was examined after isolation by electronic cell sorting. Donor CD4+ T cells thus isolated from host spleen shortly (1 day) after i.v. transfer of thymus CD4+8- T cells were similar to freshly isolated thymus CD4+8- T cells in that they both produced little IL-2 in response to anti-CD3. However, by day 3 post-transfer, IL-2 production by donor CD4+8- T cells had more than doubled and by day 8, they produced IL-2 levels comparable to those of host spleen CD4+8- T cells. A similar acquisition of high level IL-2 inducibility in thymus CD4+8- T cells upon i.v. transfer into Thy-1.1-congenic hosts was also observed using allogeneic cells as the stimulus of IL-2 production. When thymus CD4+8- T cells were intra-thymically transferred into Thy-1.1-congenic hosts, those donor cells that emigrated to the periphery became high IL-2 producers in a time-dependent manner, whereas those that remained inside the thymus showed no signs of up-regulation in IL-2 inducibility. Intrathymic transfer of CD4-8- thymocytes revealed that the most recent thymic emigrant CD4+8- T cells contained few IL-2-producing cells and were not functionally mature with respect to high level IL-2 inducibility.  相似文献   

15.
70日龄星杂“579”小母鸡120只,随机分成A、B、C三组。C组为对照组。A、B两组分别以32和8Lx的强度补充光照,使其每天的光照时间达14h。从70日龄起,每10天称重一次;从开产日龄起,对每只鸡的产蛋分别按日龄称重、登记。结果表明,光照强度与鸡的生长速度和平均蛋重相关不显著,而与鸡的性成熟和产蛋量显著相关。用放射免疫分析法测定了三组鸡100~180日龄间外周血浆E_2、LH和T_4含量,B组鸡LH峰值最高,其峰值(149日龄)与基础值(100日龄)对比,增长率为231.4%;A组鸡血浆T_4水平增加明显,但其产蛋量相对较低;补充光照组能促使血浆E_2峰值的出现早于自然光照组,但各组鸡E_2峰值无显著差异。  相似文献   

16.
本文测定了不同运动条件下的大鼠骨骼肌中的雄激素受体结合容量及雄激素的水平。一次力竭运动可使大鼠股四头肌组织的雄激素结合容量水平上升,但降低了其组织中的雄激素水平。在长期力竭性运动后,股四头肌组织雄激素受体结合容量及雄激素水平的均没有变化,而长期的适宜运动则可提高股四头肌的雄激素结合容量的水平,但对其雄激素的水平仍无影响。  相似文献   

17.
对黑曲霉(Aspergillus niger)高产菌株T21和原始菌株3.795糖化酶的基因表达从菌体生长、酶形成动力学、glaA基因拷贝数、糖化酶mRNA含量及其稳定性等多个方面进行了分析和比较。T21和3.795糖化酶的大量产生均自菌体生长的静止期开始。培养72h后,两者的菌体浓度相同,但T2l产生的糖化酶量为3.795的10~17倍,说明糖化酶产量的差异不是因生物量或酶起始合成期不同引起的,而是由于细胞内酶表达量不同引起的。Northern杂交显示T21总RNA中糖化酶mRNA含量为3.795的4.3~4.4倍.两菌株glaA基因拷贝数及糖化酶mRNA的稳定性分析结果排除了这两个因素的影响,因此T21糖化酶mRNA含量的增加主要是glaA基因转录水平提高的结果。T21与3.795之间糖化酶水平差异(10~17倍)与糖化酶mRNA水平差异(4.3~4.4倍)的不一致性,提示T21和3.795之间除转录水平外可能还存在着翻译水平上的差异(2~4倍)。此外,T21和3.795均存在着对糖化酶基因表达的碳源调控机制,根据两者在淀粉、麦芽糖和葡萄糖培养条件下所产生的mRNA比均为4:3:2,可以认为,这种调控作用发生在转录水平上,并且具有相同的调控方式。  相似文献   

18.
This study investigated the recovery of locomotory activity in exhausted juvenile rainbow trout (Oncorhynchus mykiss, approximately 6-10-cm fork length) in response to two conditions: (1) direct transfer to a range of velocities (0-15 cm s(-1)) in a swim flume (forced swimming) and (2) direct transfer to a pool downstream of a swim channel where a choice of velocities was presented: 2-3 cm s(-1) in the lower half of the pool, a range of velocities from 7 to 40 cm s(-1) in the upper half the pool near the channel entrance, and a velocity of 57 cm s(-1) in a swim channel emptying into the pool (volitional swimming). Exhausted trout showed a pronounced delay in the recovery of normal locomotory activity. With forced swimming, the time required to resume swimming was inversely proportional to water velocity. At 15 cm s(-1), almost all exhausted fish recovered immediately, whereas it took about 1 h for recovery at a current of 5 cm s(-1). In contrast, nonexhausted fish responded to imposed velocity with immediate rheotactic responses (orientation and station holding) at all test velocities. In voluntary swim trials, exhausted trout showed a marked preference for holding station in current in the downstream pool (approximately 11 cm s(-1)) but took, on average, 2 h longer than nonexhausted fish to make transits in the swim channel. Moreover, their ground speed in the swim channel was significantly slower. We conclude that swimming performance is impaired for at least 6 h by exhaustive exercise. Maladaptive behaviors during this time include a preference for current near the surface over cover and a reduced capacity for burst activity, both of which would translate into greater predation risk and reduced ability to forage.  相似文献   

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