共查询到19条相似文献，搜索用时 21 毫秒
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精氨酸是一种条件性必需氨基酸,在生理调节方面具有重要的功能。在正常情况下,成年动物对精氨酸的需求可以通过内源性合成满足,但在应激条件下,内源合成的精氨酸不足以满足机体的需求。精氨酸代谢可合成一氧化氮(NO),NO在体内发挥着重要的生理作用。文中综述了高温热应激对母猪的影响、精氨酸在体内的代谢过程及在抗氧化应激方面的作用,以促进高温热应激条件下精氨酸在母猪中的应用及研究。 相似文献
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氨基酸对妊娠母猪繁殖性能的影响及其作用机理 总被引：1，自引：0，他引：1
林可 《国外畜牧学(猪与禽)》2010,30(5):39-42
在所有的家畜中,猪的胎儿宫内发育迟缓(Intrauterine Growth Retardation,IUGR)问题最严重,其妊娠期胚胎及胎儿死亡率高达50%。胎盘功能不全是母猪繁殖性能不佳和仔猪初生重较低的主要原因。通过营养措施增强胎盘的生长和功能,可为提高胚胎和胎儿的存活及生长提供一种有效的解决方案。笔者发现,妊娠早期即胎盘生长最快的时期,母猪尿囊液(营养物质的储备库)所含氨基酸中精氨酸家族的含量出现不寻常的丰富。精氨酸通过代谢可生成鸟氨酸、脯氨酸和一氧化氮(NO),这些产物在体内发挥着许多重要的生理功能。更为重要的是,NO是血管舒张和血管生成因子,然而鸟氨酸和脯氨酸是胎盘合成多胺的底物,后者又是蛋白质合成和血管生成的重要调节物质。此外,精氨酸、亮氨酸、谷氨酰胺和脯氨酸可激活体内哺乳动物雷帕霉素靶蛋白(mTOR)信号通路,从而促进蛋白质合成和胎盘细胞生长。为了将有关氨基酸生物化学和营养的基础研究应用于生产实践,在小母猪妊娠的第14～28天或第30～114天,在其日粮中添加0.83%的L-精氨酸,结果母猪的产活仔数及其初生窝重均得到了提高。同时,在妊娠母猪日粮中添加0.4%L-精氨酸和0.6%L-谷氨酰胺,可提高营养物质的利用率,降低仔猪初生体重的个体差异,提高窝初生重。功能性氨基酸通过调节NO、多胺和蛋白质的合成,可刺激胎盘生长和母体营养物质通过胎盘向胎儿的转运,从而促进孕体的存活和生长发育。 相似文献
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Endometrial nitric oxide synthase activity in mares susceptible or resistant to persistent breeding‐induced endometritis and the effect of a specific iNOS inhibitor in vitro 
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下载免费PDF全文 FA Khan TS Chenier RA Foster J Hewson EL Scholtz 《Reproduction in domestic animals》2018,53(3):718-724
Emerging research suggests that the nitric oxide system may play a role in persistent breeding‐induced endometritis (PBIE) in the mare. Differences in uterine nitric oxide (NO) levels between mares susceptible or resistant to PBIE and a dose‐dependent inhibitory effect of NO on uterine contractility have been demonstrated. The objectives of this study were to investigate the difference in total nitric oxide synthase (NOS) activity of the endometrium between susceptible and resistant mares and the effect of a specific inducible nitric oxide synthase (iNOS) inhibitor on the endometrial NOS activity in vitro. Six susceptible and six resistant mares were selected based on preset criteria and the results of an intrauterine challenge with killed spermatozoa during oestrus. Endometrial biopsy samples were collected 24 hr post‐challenge and cultured at 37°C for 24 hr in L‐arginine supplemented minimum essential medium with or without a specific iNOS inhibitor (1,400 W dihydrochloride, 1 mM). The medium and the cultured endometrial tissue were collected after 24 hr of culture and assayed for NO and total protein, respectively. Total NO content of the medium, normalized to endometrial tissue wet weight or total protein, was used as a measure of endometrial NOS activity. Non‐parametric tests were applied for statistical analysis. Susceptible mares had significantly greater endometrial NOS activity than resistant mares. The iNOS inhibitor treatment significantly reduced NOS activity in endometrial samples derived from susceptible and resistant mares. These findings provide a basis for in vivo testing of specific iNOS inhibitors as preventative or therapeutic options for PBIE in mares. 相似文献
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Nitric oxide (NO) is an endogenous gas that serves as a biologic messenger in many physiologic processes including neurotransmission, blood-pressure control, the immune system's ability to kill tumor cells, and wound healing. NO is produced after oxidation of L-arginine by a family of nitric oxide synthase (NOS) enzymes. Two of the NOS enzymes are present continuously and are thereby termed constitutive NOS. One of the enzymes, inducible NOS, is not typically expressed in resting cells and is induced by various substances including endotoxin, some cytokines, and microbial products. Thus, NO often has paradoxical activities. When NO is over- or underproduced, it can result in potentiation of disease states with disastrous results. This review discusses the biochemistry of NO, its functions in normal and disease states, and therapy for modulating NO production in disease states. 相似文献
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一氧化氮（Ｎｉｔｒｉｃ ｏｘｉｄｅ,ＮＯ）是一种难溶于水的脂溶性气体。它在体内扮演着生理和病理的双重角色。小剂量ＮＯ有着重要的信息传递作用。在神经系统中具有类似神经递质的信息传递功能,在免疫系统中具有杀灭肿瘤细胞、细菌、寄考虫和病毒的作用;在心血管系统中具有扩张血管,抑制血小板聚集与粘附,调节血流和血压的功能,但大剂量ＮＯ,又可产生细胞毒笥,导致组织细胞损伤,是肝组织损伤的重要介导因子。 相似文献
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精氨酸在体内和体外试验中对鲤鱼免疫力的影响 总被引：1，自引：0，他引：1
本试验采用体外和体内2种方法来研究精氨酸(Arg)对鲤鱼免疫力的影响。体外试验中,在培养基中分别添加0、0.5、1.0、1.5和2.0mmol/L的Arg,将肾脏白细胞培养不同的时间段后测定增殖指数、呼吸爆发活力、吞噬活力和杀菌率。体内试验中,将平均体重37g的鲤鱼随机分为5组,每组3个重复,每个重复10条,分别体内注射0、25、50、100和200 mg/kg鱼体重的Arg,商业饲料投喂2周,进行肾脏白细胞增殖指数、呼吸爆发活力和吞噬活力的测定,以及血清和肝胰脏一氧化氮(NO)含量、一氧化氮合成酶(NOS)活性及血清白蛋白(ALB)含量的测定。体外试验结果表明:添加Arg能够提高肾脏白细胞的增殖指数、呼吸爆发活力、吞噬活力和杀菌率。培养12和24h后,1.0、1.5和2.0mmol/L Arg组肾脏白细胞增殖指数显著高于0mmol/L Arg组(P0.05);培养6、12和24h后,1.0mmol/L Arg组肾脏白细胞呼吸爆发活力显著高于0mmol/L Arg组(P0.05);培养12和24h后,1.0、1.5和2.0mmol/L Arg组肾脏白细胞吞噬活力显著高于0mmol/L Arg组(P0.05);培养18h后,1.0、1.5和2.0 mmol/L Arg组肾脏白细胞杀菌率显著高于0 mmol/L Arg组(P0.05)。体内试验结果表明:50、100和200 mg/kg Arg组肾脏白细胞呼吸爆发活力、吞噬活力和增殖指数显著高于0mg/kg Arg组(P0.05);100和200mg/kg Arg组血清ALB和NO含量显著高于0 mg/kg Arg组(P0.05),50、100和200mg/kg Arg组血清NOS活性显著高于0mg/kg Arg组(P0.05);50、100和200mg/kg Arg组肝胰脏NO含量显著高于0mg/kg Arg组(P0.05),25和50mg/kg Arg组肝胰脏NOS活性显著高于0mg/kg Arg组(P0.05)。由此可见,Arg提高了鲤鱼肾脏白细胞的免疫力,体外试验表明Arg的适宜浓度为1.0mmol/L。正常摄食情况下,Arg在鲤鱼体内注射适宜浓度为50~100mg/kg。 相似文献
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Pseudorabies virus induces a rapid up-regulation of nitric oxide synthases in the nervous system of swine 总被引：3，自引：0，他引：3
Marcaccini A López-Peña M Bermúdez R Quiroga MI Guerrero FH Nieto JM Alemañ N 《Veterinary microbiology》2007,125(3-4):232-243
Nitric oxide (NO) is a free radical gas with important roles in the host's immune response against viral infections. In this study, we examined the kinetics and distribution of nitric oxide synthase (NOS) expression during the early steps of infection of the porcine nervous system by the alphaherpesvirus pseudorabies virus (PRV). To this end, we examined changes in the expression of the three major NOS isoforms, neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS), by immunohistochemistry in the trigeminal ganglia and brain of pigs inoculated intranasally with a virulent PRV strain. The results obtained show that infection of the porcine nervous system by PRV induced a rapid and progressive increment in NOS expression that coincided in timing, location, and magnitude with those of virus propagation in the nervous tissue. A major finding of this study was that PRV caused not only nNOS and iNOS induction in a variety of cell types, but also eNOS up-regulation in endothelial cells and neurons; therefore, all possible sources of NO are activated and probably contribute to the overproduction of NO during infection with the neurotropic alphaherpesvirus PRV in its natural host. 相似文献
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肺动脉压升高是肉鸡肺动脉高压综合征(PHS)的重要发病机制。近年来研究表明一氧化氮(NO)在PHS发生发展中发挥着重要作用。本文论述了NO对肉鸡PHS发病过程的影响。一氧化氮合酶(NOS)和NO活性在PHS早期升高而后期下降。NO具有强大的扩张血管的作用,但在PHS过程中,NO合成相对不足,导致肺血管舒缩失衡,引起肺动脉压升高。肺血管重构是肉鸡肺动脉高压综合征的重要病理学变化特征,而NO可促进肺小动脉平滑肌细胞凋亡,在一定程度上抑制肺血管重构的形成。NO作为自由基对机体造成的损伤也是引起PHS的原因之一。在肉鸡日粮中补充NO前体物L-精氨酸可以增加内源性NO的生成,有助于降低PHS的发病率。 相似文献
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Bull spermatozoa were examined for the presence and localization of constitutive Nitric Oxide Synthase (NOS), as nitric oxide (NO) is involved in calcium-dependent capacitation. In bull spermatozoa, NO generation is enhanced by l-arginine (3 microm) and abolished by the NOS-inhibitor N-nitro-l-arginine methyl ester (l-NAME). In addition, presence of NOS in bull spermatozoa was verified by immunohistochemistry, revealing the existence of both neuronal NOS (nNOS) and endothelial NOS (eNOS) immunoreaction. These findings were confirmed by Western blot technique, showing immunoreactive bands at 161 kDa (nNOS) and 133 kDa (eNOS). Confocal laser microscopy localized nNOS related immunofluorescence at the acrosome cap of sperms and their flagellum-mainpart. This technique also identified eNOS staining spread over the spermatozoan head. In conclusion, immunohistochemistry, Western blot technique, and NO generation suggest the presence of n- and eNOS in bull spermatozoa. 相似文献