Research Progress on Regulatory Mechanisms of Canine Corpus Luteum Function

Significant differences can be found in the physiology construction and functional performance of canine corpus luteum from the other domestic animal species, and the most interesting characteristic is the lack of an acute luteolytic mechanism. It is a multifactorial process that luteinization of canine is regulated by PRL, LH and PGE₂, and the luteolysis is insensitive to PGF_2α. The remaining canine corpus luteum plays an important role in bitch reproductive activities, and the steroid hormone from it through autocrine or paracrine is the same important to pregnancy and the estrus cycle. It is still unknown about the mechanism of regression of canine corpus luteum, however, there are several hypotheses including the passive regression mechanism. Moreover, corpus luteum is one of the few tissues (organs) which includes all three parts formation, maintenance and regression of the life cycle, and it is very important for the research of inflammatory reaction, carcinogenesis and apoptosis. In this review, the advanced progress of formation and regression of canine corpus luteum were summarized, which would provide theoretical basis and research background to study the molecular mechanism in this filed.     

黄体退化的分子机制及早期黄体钝化的某些原因探讨

黄体退化是生殖过程中的一个重要过程 ,它控制着生殖周期的长短 ,与妊娠的建立和维持密切相关 ,已证实前列腺素F2α、催产素、内皮素 1及一氧化氮合酶等多种因素参与黄体退化过程。在黄体发育早期 ,外源PGF2α不能诱导黄体溶解 ,可能原因有 :(1)早期黄体内缺乏内皮素 1,(2 )黄体早期生物学反应减弱导致受体脱敏 ,(3)早期黄体中存在PGF2α代谢酶 ,(4)PGF2α不能激活黄体细胞内蛋白激酶C效应体系     

与溶黄体有关的细胞成分

反刍家畜黄体的退化取决于子宫释放的ＰＧＦ２α，然而ＰＧ诱导黄体细胞水平退化的实际机制尚知之甚少，许多研究认为ＰＧＦ２α对黄体细胞似乎能产生多种效应。大黄体细胞可能最初对溶黄体信号起反应，但其退化过程也许需要大小黄体细胞间以及黄体细胞与非黄体细胞间的交流传达。免疫系统似乎被有效地包含在溶黄体过程中，因胞分泌物起反应，这也许会导致涉及黄体退化的其它机制的发现。     

表观遗传调控机制在犬肿瘤中的研究进展

犬肿瘤性疾病是兽医临床上常发的一种疾病,其发病率较高,是造成世界范围内犬死亡的重要原因之一,由于其病理学分类、自发性、基因和信号通路等方面与人类肿瘤有相似之处,可作为人类肿瘤的研究模型。表观遗传是基于DNA序列没有发生改变的情况下所致基因功能和表达水平发生了可遗传的变化,主要通过基因转录或翻译过程的调控,影响其功能和特性。表观遗传改变主要包括DNA甲基化水平改变、组蛋白修饰、染色质重塑和非编码RNA调控等。DNA异常甲基化在犬的多种肿瘤中均有研究,包括犬白血病、淋巴瘤及黑色素瘤等,且犬与人类肿瘤的DNA异常甲基化模式相似。在肿瘤中组蛋白各种修饰酶表达失调,是抗肿瘤药物开发分子靶点研究的主要焦点,但目前在犬肿瘤中的研究较少。非编码RNA中microRNA与lncRNA是目前的研究热点,已有较多研究致力于开发针对非编码RNA的靶向研究药物,但目前在兽医领域应用较少。作者主要综述了犬肿瘤疾病的流行病学、DNA甲基化、组蛋白修饰、非编码RNA等表观遗传学变化在犬肿瘤中的研究进展,揭示表观遗传异常与犬肿瘤发生发展的关系,以期为开发犬肿瘤性疾病诊断、靶向治疗及预后的特异性标志物提供参考依据。     

黄体机能与生长因子关系的研究进展

论述了黄体的形成和机能 ,同时介绍了EGF、TGF、IGF和VEGF等生长因子对黄体的调控作用     

犬腹泻及其防制

犬腹泻 (Diarrheaindog)是兽医临床上常见的一种症状。它是一种导致犬营养不良 ,生长发育障碍和丧失工作能力的重要因素 ,严重时可导致死亡 ,给养犬业带来巨大的经济损失。为了快捷和有效地对犬腹泻进行诊断、控制和预防 ,对其病因、发生机制、诊断及防制进行综述。     

家兔腹泻发生机制及调控研究进展

家兔腹泻是危害养兔业的重要疾病之一,发病率及死亡率高、损失大且难于治愈。是世界各国养兔者普遍关注的问题。多年来许多专家学者致力于该病的研究并取得了可喜的成果。     

家兔腹泻发生机制及调控的研究进展

家兔腹泻病是危害养兔业的重要疾病之一，发病率及死亡率高、损失大且难于治愈，是世界各国养兔者普遍关注的问题。多年来许多专家学者致力于该病的研究并取得了可喜的成果。     

犬、猫呕吐的发病原因及其机制的研究进展

呕吐是一种反射活动,通过口腔强行排出上消化道物质。呕吐可以作为一种防止食物中毒的保护机制,也可以是疾病发生发展的病理反应。呕吐反应是一个复杂的过程,是由呕吐递质与受体、外周和中枢神经系统共同协调作用的结果。呕吐虽不会造成动物直接死亡,但会阻碍患病动物恢复健康,甚至继发其他疾病,因此,掌握呕吐发病原因及其机制不仅有利于临床相关疾病的治疗,而且促进止吐、催吐药的研发。文章参考相关文献并且结合临床经验综述呕吐的发病原因和机制,以期为临床开发有价值的止吐药提供参考。     

犬妊娠终止技术的研究进展

犬有时会发生非计划性和不需要的交配，此时，人们往往试图终止犬的妊娠。虽然用于终止妊娠的方法很多，但效果都不大理想。如交配后立即灌洗阴道，对防止妊娠无济于事。适当使用雌激素虽能防止怀孕，但易引起子宫积脓和骨髓抑制，并且必须在可能受精的卵子到达子宫前使用；前列腺素PGF2a是一个有效的溶黄体制剂，但引起流产的剂量(1毫克／千克)和中等致死的剂量(5．13毫克／千克)相距太近，易引起犬的中毒；地塞米松每日肌肉注射2—5毫克，连续lO天，可在妊娠的第30天引起胎儿的子宫内吸收和死亡，但副作用较大；D一去乙酰一硫代秋水仙碱静脉注射可引起母犬的流产，但用药后，犬出现流涎、呕吐，腹泻等副作用。因此，人们一直在不断寻找一种有效的犬终止妊娠技术。现将有关研究进展综述如后。     

哺乳动物发情周期黄体的组织学研究进展

黄体是排卵后形成的暂时性的内分泌组织 ,在一个较短的存在期限中经历了一系列的结构变化和分泌阶段 ,对于哺乳动物维持正常的生殖功能具有重要作用。人们对黄体细胞的来源、组成、形态及大小持有不同的观点。近年来 ,人们就黄体细胞的功能和退化、溶解进行了较为深入的研究 ,发现不同动物黄体细胞的功能各有不同 ,黄体退化、溶解与细胞凋亡有密切关系。了解哺乳动物发情周期黄体的组织结构对于控制动物的繁殖具有重要意义。文章对哺乳动物发情周期黄体中不同类型黄体细胞的来源、组成、形态、功能及退化、溶解 ,黄体细胞的分泌方式和超声波在黄体研究中的运用作了概述     

藿芪灌注液治疗奶牛卵巢静止和持久黄体的临床试验

将确诊为患持久黄体和卵巢静止的病牛各40头,随机分为4组,分别为藿芪灌注液高、中(推荐剂量)、低剂量治疗组和促孕灌注液对照治疗组,每组10头。试验组每头牛分别按每次150mL、100mL和50mL的剂量子宫灌服,隔日1次,4次为1个疗程。对照药物治疗组为促孕灌注液,每次100 mL,隔日1次,4次为1个疗程。结果显示,用藿芪灌注液治疗奶牛持久黄体的高、中、低剂量组的治愈率分别是80%、70%和50%,总有效率分别是90%、90%和60%。对照组治愈率80%,总有效率90%。高剂量组、中剂量组和对照组的治愈率和总有效率均显著高于低剂量组(P0.05),高剂量组与中剂量组之间无显著性差异(P0.05),藿芪灌注液高、中剂量组与对照药物组之间无显著差异(P0.05)。用藿芪灌注液治疗奶牛卵巢静止高、中、低剂量组的治愈率分别是90%、80%和60%,总有效率分别是100%、100%和70%;对照组治愈率80%,总有效率90%,高剂量组、中剂量组和对照组的治愈率和总有效率均显著高于低剂量组(P0.05),高剂量组与中剂量组之间无显著性差异(P0.05),高、中剂量组与对照组之间无显著差异(P0.05)。     

奶牛黄体发育状况与受胎率的关系

在奶牛繁殖育种工作中，最重要的是提高受胎率。影响受胎率的因素很多。如饲养管理不当，营养不均衡等。但最终起主导作用的还是卵巢中黄体发育的好坏。通过试验初步证明。人工授精后第5天黄体直径达到0.5cm以上者才能有好的受胎率。     

Effect of Chronic Administration of Oxytocin on Corpus Luteum Function in Cycling Mares

The objective of this study was to determine if intramuscular administration of 60 units of oxytocin once daily for 29 days, regardless of when treatment was initiated during the estrous cycle (i.e., without monitoring estrous behavior and/or detecting ovulation), would induce prolonged corpus luteum (CL) function in cycling mares. Mares were randomly assigned to two groups: (1) saline-treated control (n = 7) and (2) oxytocin-treated (n = 9) subjects. Control mares received 3 cc of saline, and oxytocin-treated mares received 60 units (3 cc) of oxytocin intramuscularly for 29 consecutive days. Treatment was initiated in all mares on the same day (day 1), independent of the day of the cycle. Jugular blood samples for determination of progesterone concentration were collected three times weekly (M, W, and F) for 21 days before treatment was initiated to confirm that all mares had a luteal phase of normal duration immediately before treatment. Beginning on the first day of treatment, blood samples were collected daily for eight days and then three times weekly through day 80. Mares were considered to have prolonged CL function if serum progesterone remained >1.0 ng/mL continuously for at least 25 days after the end of the treatment period. The proportion of mares with prolonged CL function was higher in the oxytocin-treated group than in the saline-treated group (7/9 vs. 1/7, respectively; P < .05). Three of the seven oxytocin-treated mares that developed prolonged CL function initially underwent luteolysis within 4–7 days of the start of oxytocin treatment and then developed prolonged CL function after the subsequent ovulation during the treatment period. In the other four oxytocin-treated mares that developed prolonged CL function, progesterone remained >1.0 ng/mL throughout the treatment period and into the post-treatment period. All mares with prolonged CL function maintained elevated progesterone concentrations through at least day 55 of the study. In conclusion, intramuscular administration of 60 units of oxytocin for 29 consecutive days effectively prolonged CL function in mares, regardless of when treatment was initiated during the estrous cycle. Importantly, this represents a protocol for using oxytocin treatment to prolong CL function that does not require detection of estrous behavior or day of ovulation.     

外源Se对胚胎移植受体母羊黄体发育和血清中激素水平的影响

 为了确定补硒对缺硒地区（陕西省神木县）绵羊繁殖性能的影响,60只受体母羊在舍饲条件下被随机分成试验组（n=30）和对照组（n=30）,试验组肌肉注射亚硒酸钠维生素E注射液4 mL/只(含硒0.46 mg/mL),对照组未注射。第25 d进行胚胎移植时,检查黄体发育情况,同时采集血样,测定血清中的6项激素（T3,T4,FSH,LH,E2,P4）水平。结果表明：补硒母羊平均每只羊有发育良好的黄体2.6枚,比对照组高1.1枚。血清T3平均水平为4.48 nmol/L,比对照组高0.93 nmol/L(P＜0.05),血清中T4平均水平为8.67 nmol/L,比对照组低3.53 nmol/L（P＜0.05）。E2和P4的浓度均显著高于对照组（P＜0.05）。可见,补硒可提高受体绵羊的黄体数量和质量以及血清E2、P4水平,但对血清FSH和LH没有明显影响。     

不同等级黄体与水牛胚胎移植受胎率关系的研究

[目的]为了解胚胎移植过程中不同等级黄体与水牛胚胎移植受胎率之间的关系,为提高水牛受胎率提供依据.[方法]在水牛胚胎移植过程中,利用B超对受体卵巢进行扫描,确定黄体的有无并根据黄体大小对其分级.黄体直径在1.5 cm以上的定为A级,直径在0.8～1.5 cm之间的定为B级,直径在0.8 cm以下的定为C级.测定受体移植...     

犬瘙痒性皮肤病研究进展

瘙痒是犬皮肤病的典型临床症状之一,通常除瘙痒外还常伴脱毛、红斑等皮肤症状。瘙痒问题不仅困扰动物本身,也影响到饲养者的生活质量。瘙痒的发生机制复杂,目前国内外已有大量对人和犬瘙痒性皮肤病的临床和基础研究,揭示了瘙痒和神经免疫系统之间的关系,引入了“瘙痒-抓挠”循环的概念,且表明了免疫系统、皮肤屏障和神经系统的单独促进作用和交互作用是瘙痒产生的关键因素,任一环节的问题都可开启“瘙痒-抓挠”的恶性循环。临床上引起犬瘙痒的病因复杂,参照2007年由国际瘙痒研究论坛成员提出的瘙痒分类,将引起犬瘙痒的疾病根据病因类比对应分为了六大类,引起皮肤病性瘙痒的疾病分为了感染性、过敏性、肿瘤性等,其中在临床上最主要的是犬过敏性瘙痒。犬瘙痒性皮肤病的诊断方法及鉴别诊断多样,需从多方面对患病犬进行信息收集,按一定顺序进行排查和鉴别诊断。犬瘙痒性皮肤病的治疗周期长且疾病易反复,目前常用的西医药物存在副作用大、靶点单一、价格昂贵等不足,中药方剂成分复杂,有效成分多,可从多通路多途径治疗机制复杂的瘙痒,在犬瘙痒性皮肤病的治疗上具有优势和广阔前景。文章对瘙痒发生的机制、犬瘙痒性疾病的分类、诊断及中西医治疗思路等最新研究...     

Expression of Aldo-keto Reductase 1C23 in the Equine Corpus Luteum in Different Luteal Phases

Regression of the corpus luteum (CL) is characterized by a decay in progesterone (P₄) production (functional luteolysis) and disappearance of luteal tissues (structural luteolysis). In mares, structural luteolysis is thought to be caused by apoptosis of luteal cells, but functional luteolysis is poorly understood. 20α-hydroxysteroid dehydrogenase (20α-HSD) catabolizes P₄ into its biologically inactive form, 20α-hydroxyprogesterone (20α-OHP). In mares, aldo-keto reductase (AKR) 1C23, which is a member of the AKR superfamily, has 20α-HSD activity. To clarify whether AKR1C23 is associated with functional luteolysis in mares, we investigated the expression of AKR1C23 in the CL in different luteal phases. The luteal P₄ concentration and levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) mRNA were higher in the mid luteal phase than in the late and regressed luteal phases (P<0.05), but the level of 3β-HSD protein was higher in the late luteal phase than in the regressed luteal phase (P<0.05). The luteal 20α-OHP concentration and the level of AKR1C23 mRNA were higher in the late luteal phase than in the early and mid luteal phases (P<0.05), and the level of AKR1C23 protein was also highest in the late luteal phase. Taken together, these findings suggest that metabolism of P₄ by AKR1C23 is one of the processes contributing to functional luteolysis in mares.