Immunohistochemical localization in the rat brain of the precursor for thyrotropin-releasing hormone

A rabbit antiserum to a peptide sequence present in the precursor for thyrotropin-releasing hormone (proTRH), deduced from cloned amphibian-skin complementary DNA, was raised by immunization with the synthetic decapeptide Cys-Lys-Arg-Gln-His-Pro-Gly-Lys-Arg-Cys (proTRH-SH). Immunohistochemical studies on rat brain tissue showed staining of neuronal perikarya in the parvicellular division of the paraventricular nucleus of the hypothalamus and the raphe complex of the medulla, identical to that already described for thyrotropin-releasing hormone (TRH). Immunostaining was abolished by preincubation with proTRH-SH (10(-6)M) but not TRH (10(-5)M). Both TRH precursor and TRH were located in neurons of the paraventricular nucleus. However, in contrast to the findings for TRH, no staining was observed in axon terminals of the median eminence. These results suggest that a TRH precursor analogous to that reported in frog skin is present in the rat brain and that TRH in the mammalian central nervous system is a product of ribosomal biosynthesis.     

Thyrotropin-releasing hormone induces rhythmic bursting in neurons of the nucleus tractus solitarius

The nucleus tractus solitarius (NTS) contains neurons that are part of the central neuronal network controlling rhythmic breathing movements in mammals. Nerve terminals within the NTS show immunoreactivity to thyrotropin-releasing hormone (TRH), a neuropeptide that has potent stimulatory effects on respiration. By means of a brainstem slice preparation in vitro, TRH induced rhythmic bursting in neurons in the respiratory division of the NTS. The frequency of bursting was voltage-dependent and could be reset by short depolarizing current pulses. In the presence of tetrodotoxin, TRH produced rhythmic oscillations in membrane potential whose frequency was also voltage-dependent. These observations suggest that TRH modulates the membrane excitability of NTS neurons and allows them to express endogenous bursting activity.     

Thyrotropin-releasing hormone precursor: characterization in rat brain

To characterize the precursor of mammalian thyrotropin-releasing hormone (TRH), a rat hypothalamic lambda gt11 library was screened with an antiserum directed against a synthetic peptide representing a portion of the rat TRH prohormone. The nucleotide sequence of the immunopositive complementary DNA encoded a protein with a molecular weight of 29,247. This protein contained five copies of the sequence Gln-His-Pro-Gly flanked by paired basic amino acids and could therefore generate five TRH molecules. In addition, potential cleavage sites in the TRH precursor could produce other non-TRH peptides, which may be secreted. In situ hybridization to rat brain sections demonstrated that the pre-proTRH complementary DNA detected neurons concentrated in the parvocellular division of the paraventricular nucleus, the same location as cells detected by immunohistochemistry. These findings indicate that mammalian TRH arises by posttranslational processing of a larger precursor protein. The ability of the TRH prohormone to generate multiple copies of the bioactive peptide may be an important mechanism in the amplification of hormone production.     

南京地区奶牛日粮中添加碘对产奶性能和甲状腺机能的影响

选用10头健康成年黑白花奶牛、按2×2交叉试验设计进行饲养试验。试验组日粮中添加KT20mg/头·日,对照组不添加。试验期70天(2×35),于各试验期最后一天进行促甲状腺素释放激素(TRH)兴奋试验。结果试验组奶牛日平均产奶量(kg)、乳脂率(％)分别为20.01±1.06和3.45±0.05,均显著高于对照组(P<0.05),折合成标准乳(4％FCM),试验组较对照组提高了7.7％(P<0.05)。注射TRH前,血清中甲状腺素(T_4)、三碘甲腺原氨酸(T_3)和促甲状腺素(TSH)含量试验组均显著高于对照组(P<0.05);注射TRH后60min,两组血清中T_4、T_3、TSH含量极显著上升(P<0.01),试验组T_4上升值显著高于对照组(P<0.05),而T_3、TSH上升值则无组间差异(P<0.05)。提示:南京地区冬春两季饲料条件下,日粮中添加适量碘(20mgKI/头·日)可显著促进T_4的合成与储备,改善垂体-甲状腺轴分泌机能,进而提高奶牛产奶性能。     

Thyrotropin-releasing hormone: regional distribution in rat brain

A sensitive and specific radioimmnunoassay has been used to measure the distribution of thyrotropin-releasing hormone (TRH) in rat brain. All areas of brain tested, except cerebellum, contained readily measurable amounts of TRH. The hypothalamus contained only 31.2 percent of the total brain content of TRH. These results support recent suggestions of central actions for TRH in addition to its hypophysiotropic functions.     

Effects of cold stress on hypothalamic corticotrophin-releasing and thyrotropin-releasing hormone messenger RNA levels in chickens

There is increasing evidence that stress can activate the hypothalamic-pituitary-adrenal-axis and hypothalamic-pituitary- thyroid-axis,and further affect the synthesis and secretion of corticotrophin-releasing hormone(CRH)and thyrotropin-releasing hormone(TRH).To evaluate the effect of cold stress on the hypothalamic CRH and TRH messenger RNA(mRNA)levels in Yisha chickens,male Yisha chickens were subjected to acute(1,6,12 h)and chronic(5,10,20 d)cold stress(12±1)℃.Hypothalami were collected for assessment of mRNA levels by semi-quantitative RT-PCR.Acute stress resulted in a significant decrease of CRH mRNA levels at 6 and 12 h,and a significant increase of TRH mRNA levels at every stress time point.Chronic cold stress resulted in a significant increase of CRH mRNA levels and a significant decrease of TRH mRNA levels compared with the control group at every stress time point.The results suggest that the two genes differently respond to cold stress at the mRNA levels.And the different degrees of cold stress will produce different effects on the identical gene.     

Human lactational and ovarian response to endogenous prolactin release

Radioimmunoassayable prolactin rises in postpartum women during nursing and after intravenous thyrotropin-releasing hormone (TRH). Prolactin release induced by TRH can be dissociated from the postsuckling response. In addition to this, increases in endogenous prolactin secretion are followed by marked breast engorgement and milk letdown, especially after intravenous TRH. In this group of breast-feeding women, vaginal smears remained atrophic even up to 410 postpartum days. Prolactin appears to influence the production of breast milk, and the maintenance of a regular nursing pattern seems to promote the maintenance of ovarian unresponsiveness to circulating gonadotropins.     

种子包衣剂对棉花育苗的影响

2002年,采用自行研制的10种棉花种子包衣剂M,MPS,HZ-10B,TRL,TRO,WF-1,TRH,TRPS,MH-2B和TRM包衣棉花种子,进行大田直播育苗、大田营养钵育苗和室内沙培育苗,研究了供试种衣剂对棉花发芽、出苗和成苗的影响．结果表明,种衣剂处理能显著提高棉花种子的发芽率、成苗率,显著降低死苗率;种衣剂处理使主根显著增长,侧根数显著增多,苗高显著降低．     

冷应激引起鸡下丘脑基因表达谱差异分析

为研究冷应激发生机制以及冷应激过程中下丘脑神经内分泌系统基因表达变化,选取28日龄淮南麻黄鸡为研究对象,采用全基因组表达谱芯片技术分析冷应激24 h后下丘脑组织差异表达基因.通过比较淮南麻黄鸡冷应激24 h前后下丘脑组织基因表达谱,表达倍数＞3倍的基因共877个,其中下调基因334个,主要涉及HAAO、CHRNA9及STAM2等信号转导接头分子基因的低表达;上调基因543个,主要为CCK、NPY及其受体基因、CAMK2A、SST及TRH等基因.对差异表达基因参与的生物学过程分析可见,在冷应激24 h过程中,鸡下丘脑首先启动神经受体-配体相互作用,刺激鸡体产生采食欲望,随后启动脂质代谢途径以供应机体能量需求.在此过程中,Jak-STAT、Ca离子信号通路等一系列生物反应途径发生响应,以调节机体对寒冷应激的反应.差异表达基因的生物学通路分析为阐明鸡冷应激机理提供重要信息,差异表达基因分析有助于抗冷应激分子育种候选基因筛选.     

荷斯坦牛血浆催乳素浓度遗传参数估计及其与PRL、PRLR和TRH基因关联分析

为探究奶牛血浆催乳素(Prolactin, PRL)浓度的群体特征及其在不同环境条件和生理阶段下的变化规律,估计牛血浆PRL浓度的遗传参数,探究PRL、PRLR和TRH基因多态性与血浆PRL浓度之间的相关性,本研究于2014和2017年对北京地区某规模化牧场的472头泌乳期荷斯坦牛进行血浆PRL浓度测定,共获得1 169条数据。首先,采用固定模型分析采样季节、胎次、挤奶前后和泌乳阶段对奶牛血浆PRL浓度的影响;然后,采用重复力动物模型估计血浆PRL浓度的遗传参数;此外,通过扫描PRL、PRLR和TRH基因的多态位点,对血浆PRL浓度进行基于多态位点和单倍型的关联分析。结果显示：1)泌乳期荷斯坦牛血浆PRL平均浓度为224.29 mIU/L,胎次、采样季节和泌乳阶段对血浆PRL浓度有显著或极显著影响,血浆PRL浓度随胎次和泌乳阶段的推移而逐渐升高,春季和夏季时奶牛血浆PRL浓度极显著高于秋季和冬季(P<0.01);2)血浆PRL浓度的遗传力为0.02,为低遗传力性状;3)PRL和PRLR基因基因中未发现与血浆PRL浓度显著相关的SNP位点,TRH基因的rs137596325、rs1...     

鄱阳湖乌鳢不同组织EST和LDH同工酶的研究

采用聚丙烯酰胺垂直梯度凝胶电泳法对鄱阳湖乌鳢脾脏、肌肉、心脏、肝脏和肾脏5种组织中的酯酶(EST)和乳酸脱氢酶(LDH)同工酶进行了研究。结果表明,乌鳢EST同工酶共检测到10条酶带,9种同工酶在肝脏中均有表达,在心脏中只检测到5种同工酶;LDH同工酶共检测到6条酶带,有5种同工酶在心脏表达,而在肝脏中只表达1种且色带较浅。可见乌鳢2种同工酶的分布具有明显的组织特异性。     

僵藕的发病症状及细胞结构

观察研究了僵藕的形态特征和茎叶细胞的超微结构。结果表明:僵藕藕身表面出现棕褐色斑点、条斑,表皮细胞和薄壁细胞常被破坏形成空腔,薄壁细胞中淀粉粒减少,维管束衰退,导管发育不全,筛管内含物积聚,运输功能受损;叶绿体和线粒体结构混乱,膜解体、消失,细胞核核膜不清,核仁不明显;液泡内含物聚集;僵藕病叶叶肉细胞和叶脉细胞中有6~8臂的风轮状内含体,同时在僵藕病叶组织的粗提取液中发现线条状病毒粒子。     

花鲈消化系统组织学与组织化学研究

[目的]探讨花鲈的生理特性。[方法]用石蜡切片的方法,通过不同的染色方法对鲈鱼的消化道进行组织学和组织化学研究。[结果]PAS反应显示消化道各处都有黏多糖存在;AB/PAS反应显示消化道黏膜下层含有中性黏多糖,杯状细胞含有中性、酸性黏多糖。硝酸银反应显示胃体、幽门胃黏膜下层有棕黑色颗粒,表明含钙。腾氏蓝反应显示幽门胃及结缔组织中有蓝黑色颗粒,表明含铁。HE染色显示鲈鱼消化道肌肉层发达。食道、幽门及胃含有大量杯状细胞,黏液腺发达;胃部肌肉层发达。[结论]花鲈消化道结构与其肉食性密切相关。     

猪副粘病毒感染的电镜诊断及病毒的分离

采用电镜负染技术对长春市某猪场病死仔猪的肠道内容物、肾脏、脾脏、肝脏、肺脏、脑等组织进行了观察.结果在肠道内容物中发现大量副粘病毒,同时在肾脏、肝脏和肺脏中也发现数量不等的副粘病毒,在脾脏和脑组织中未发现病毒粒子.取肾脏为病料,采用同步培养方法接种于PK细胞系进行病毒的分离培养.结果表明,电镜负染技术可对猪感染副粘病毒进行快速诊断,该方法操作程序简便,速度快,从取样到结果判定在1h之内即可完成.细胞分离培养结果证实此病例中的猪副粘病毒可在PK细胞中克隆增殖,并引起细胞典型的病变(CPE).     

黄缘盒龟消化道的组织学研究

[目的]对黄缘盒龟消化道进行组织学研究.[方法]应用石蜡切片和显微照像技术,对黄缘盒龟的食管、胃、小肠和大肠进行了组织学观察.[结果]消化道管壁均由粘膜层、粘膜下层、肌层和外膜构成.食管具有纵行皱襞,可见杯状细胞,有丰富的弥散淋巴组织和一些孤立淋巴小结,未见食管腺.胃有大量的胃腺,胃腺细胞可分成2类：一类是体积较大的细胞,胞核较大,胞质嗜碱性;另一类是体积较小的细胞,胞核较小,胞质嗜酸性.肌层特别发达.小肠的表面有大量绒毛,绒毛中未见中央乳糜管.绒毛上皮细胞由吸收细胞和杯状细胞组成.肠腺由柱状细胞和少量杯状细胞构成.大肠具有粘膜皱襞和较多的杯状细胞,无绒毛,可见许多分散的淋巴小结,外膜较厚.[结论]消化道各部分的差异主要在粘膜层和肌层.     

金环胡蜂及其洞穴内其他节肢动物研究初报

报道了闽南山区金环胡蜂巢的营巢小生境、营巢洞穴以及蜂巢的结构 .蜂群由 10 2只成虫组成 ,其中雌蜂 57只 ,雄蜂 4 5只 .测量了成蜂体长 ,其中 7只雌蜂的体长最长 (平均 4 .6 cm) .在洞穴底部发现 5种节肢动物 ,其中 4种为昆虫 ,最多的是一种食蚜蝇科幼虫 ,其次是一种步甲科幼虫 ,此外还有螟蛾科幼虫、垫跗螋科的成虫和蜈蚣 ,洞穴内还有白蚁 .这些虫子很可能均是金环胡蜂洞穴内的共栖物     

东北细毛羊胎羊卵巢卵泡超微结构研究

为给胚胎工程研究提供基础材料,应用电子显微镜对东北细毛羊不同胎龄胎羊卵巢卵泡的超微结构进行了观察研究,结果表明:1)7周龄胎儿卵巢形成了原始卵泡雏形,10周龄才形成结构较完整的原始卵泡。2)卵母细胞呈圆形或椭圆形。卵母细胞膜双层不规则;核仁呈网状,单核仁或双核仁;核大多位于卵母细胞的边缘;并发现由双核构成的卵母细胞和胞质中形成不含细胞器的“透明区”;在10周胎龄卵巢,发现有1条线正将1个卵母细胞一分为二。早期线粒体多数圆形,但发现了1个线状的线粒体。随着卵母细胞发育,除圆形以外,还出现了类似菱形、不规则型、幼稚型的线粒体。单个粗面内质网可见,但高尔基体却很少见到。12周龄原始卵泡形成类似“透明带”物质。3)卵泡细胞核多数不规则,个别呈扁长形或纺锤形;卵泡细胞环绕于卵母细胞周围,早期数量少,随着卵泡发育逐渐增多。4)东北细毛羊胚胎卵巢卵母细胞发育的各阶段都有一定数量卵母细胞发生退行性变化———闭锁。     

日本海马(Hippocampus japonicus)脑垂体的组织学观察

本文应用组织学方法对日本海马(Hippocampus japonicus)脑垂体的形态结构和激素分泌细胞的鉴别作了研究。结果表明日本海马脑垂体属前后型。由腺垂体和神经垂体构成。腺垂体分为前腺垂体(RPD),中腺垂体(PPD)和后腺垂体(PI)。用O.F.G染色,腺垂体内可鉴别出七种激素分泌细胞,其中RPD内两种:促肾上腺皮质激素(ACTH)分泌细胞和催乳激素(PRL)分泌细胞;PPD内三种:生长激素(GH)分泌细胞、促甲状腺激素(TSH)分泌细胞和促性腺激素(GTH)分泌细胞;PI内两种:促黑激素(MSH)分泌细胞和一种机能不明的细胞。神经垂体狭窄,长带状位于整个腺垂体的背上方。