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生长激素对蛋白质动态代谢与氨基酸利用的调控 总被引：1，自引：0，他引：1
生长激素是调节动物生长的众多激素中最重要的一种 ,它通过在肌肉与脂肪组织之间极强的营养重分配作用 ,增加体蛋白沉积 ,减少脂肪沉积 ,从而改变这两种组织的生长状况来实现其促生长功能。动物体内蛋白沉积是蛋白合成与降解同时进行的两个过程动态平衡的结果。本文综述了近年来有关生长激素对动物蛋白质动态代谢与氨基酸利用调控方面的研究结果 ,指出生长激素使蛋白质合成与降解速率均增加 ,整体蛋白质周转代谢强度加大 ,从而导致蛋白质沉积增加。 相似文献
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肉鸡血浆生长激素含量与屠体性状的相关徐日福（胜利油田胜大集团莱建种鸡场东营２５７０５５）孙宪如（吉林农业大学动物科学系长春１３０１１８）生长激素（ＧＨ）对控制和调节正常动物的生长发育具有重要作用［１．２］，它除促进细胞内氨基酸积累增加，刺激蛋白质合成... 相似文献
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脑垂体前叶分泌的牛生长激素(BGH)是可以不通过靶腺而直接产生生理效益的激素,它本身是一种蛋白质,含188个氨基酸,现已确知其排列顺序,可人工合成。BGH的主要功能包括①促进氨基酸和蛋白质的合成,减少尿素、肌酸和氮的排出量,从而有效地利用饲料中的蛋白质和保存组织内的蛋白质;②加强脂肪降解为 相似文献
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影响动物体蛋白周转的因素 总被引：2，自引：1，他引：1
蛋白质是生命活动的物质基础，是一切细胞和组织的重要组成部分。动物体内蛋白质代谢是一个动态过程，即动物合成机体组织新蛋白质的同时，原有的组织蛋白可被降解成氨基酸，降解形成的氨基酸又可用于合成组织蛋白，使组织蛋白不断更新更替。 相似文献
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生长激素释放肽（Ghrelin）是生长激素促分泌素受体（GHS—R）的一种内源性配体，1999年由日本国立循环器病中心Kojima等人从小鼠和人的胃组织中成功分离并鉴定。Ghrelin系由28个氨基酸构成的多肽，能够和GHS—R结合而刺激生长激素GH的分泌。就目前的研究报道来看，Ghrelin除调节生长激素分泌外，还在能量平衡、胃功能、心血管系统以及肿瘤生长等诸多方面表现出重要的生物学效应。 相似文献
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生长激素释放因子(growth hormone-releasing factor,GRF)主要是由下丘脑弓状核的神经细胞分泌产生的,是一种蛋白类激素,不同动物物种的GRF有所不同.成熟的GHRH一般含有40～44个氨基酸残基,是生长激素的正性调控因子,可与生长激素释放抑制因子(somatostain,SS)共同调节生长激素(growth hormone,GH)的分泌.GRF能特异性地增加生长激素的mRNA,从而增加生长激素的生成,达到加快核酸和蛋白质的合成,减少脂肪沉积,进而影响动物的生产性能. 相似文献
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动物生长激素是由垂体前叶分泌的一种蛋白类激素,由190～191个氨基酸残基组成,它是影响动物生长、泌乳、繁殖以及新陈代谢诸过程的重要因素.其作用是促进动物生长和碳水化合物代谢、葡萄糖的吸收、脂肪分解及核酸、蛋白质的合成.生长激素基因是控制生长激素分泌水平,调节动物生长发育的主效基因,文章综述了生长激素基因的结构、表达调控以及在山羊中的研究及其应用. 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献