共查询到19条相似文献，搜索用时 172 毫秒
1.
甲状腺激素在鱼类繁殖中的作用 总被引：1，自引：0，他引：1
<正>甲状腺激素(Thyroid hormone,TH),包括三碘甲状腺原氨酸(T3)和四碘甲状腺原氨酸(T4),存在于所有的脊椎动物中。研究表明,TH对哺乳类和两栖类的早期发育和变态过程发挥着至关重要的作用,而在鱼类(尤其是鲆鲽类)的变态过程中,TH的调控作用更加明显[1,2]。近期研究发现,TH在鱼类发育的各阶段都起着重要的调节作用,其中对鱼类繁殖过程的调控作用尤为显著[3]。作者旨在阐述鱼类甲状腺的结构特征,及TH在鱼类繁殖过程中的作用。 相似文献
2.
3.
甲状腺激素在鱼类生长发育、变态、生殖、渗透调节以及摄食和营养代谢中发挥着重要作用,外源化合物对硬骨鱼的甲状腺干扰作用会导致发育和孵化延迟、运动性降低。本文首先对鱼类甲状腺激素的中枢调控、合成、转运、代谢和发挥作用的相关过程进行简要介绍,随后从核受体介导途径、非受体介导途径两个方面综述了外源污染物对硬骨鱼甲状腺的干扰作用机制,最后从物种特异性、检测指标、膜受体介导途径三个方面提出了目前研究的不足之处以及解决方法,以期为今后探究外源污染物对鱼类甲状腺系统干扰作用机制的研究提供更多的参考。 相似文献
4.
5.
所有脊椎动物生殖均受下丘脑-垂体-性腺轴的调控,多种下丘脑神经肽参与了生殖调控过程。大多数神经肽具有促进生殖的功能,例如促性腺激素释放激素(gonadotropin-releasinghormone,GnRH)、神经激肽B (neurokinin B, NKB)、神经肽Y (neuropeptide Y, NPY)、神经分泌素(secretoneurin, SN)、刺鼠相关蛋白(agouti-related peptide, AgRP)、甘丙肽(galanin, GAL)和吻素(kisspeptin, Kiss)。Spexin (SPX)是一种新型下丘脑神经肽,属于SPX/GAL/Kiss家族成员。SPX的成熟肽由14个氨基酸组成,该氨基酸序列在不同物种间高度保守。SPX可以激活GAL受体2和3 (GALR2/3)参与生殖、摄食等多种生理过程。本文围绕鱼类SPX基因鉴定、进化分析、组织分布、表达调控、生理功能以及信号转导机制等方面,简要总结鱼类SPX及其受体的研究进展,以期为后续深入研究提供参考。 相似文献
6.
在热处理血清样品的基础上建立了鱼类血清睾酮（T）的放射免疫双抗体测定法。分别在不同性腺发育时期对花尾胡椒雌鱼，进行人绒毛膜促性腺激素（HCG）和促黄体生成素释放激素类似物（LHRH－A）注射。结果，在性腺发育期，HCG和LHRH－A均能在注射后6h显著升高血清睾酮水平；注射后24h，无论HCG还是LHRH－A处理的血清睾酮水平均下降至与对照差异不显著。在性腺未发育期，HCG和LHRH－A均未能引起血清睾酮水平的明显变化。结果提示：花尾胡椒鲷雌鱼促性腺激素分泌受促黄体生成素释放激素刺激。在性腺未发育期和性腺发育期,垂体－性腺轴对外源激素的反应性存在明显差异，性腺发育期有显著反应，而性腺未发育期没有反应，提示只有在性腺发育期注射外源激素才能诱导的性腺发育。 相似文献
7.
“碘”是甲状腺合成甲状腺激素所必需的微量元素。甲状腺素对人和动物的正常生长都是必不可缺的,凡是甲状腺激素所具有的各种生物学功能,诸如维持能量代谢、调节新陈代谢、对垂体功能的支持作用、促进体格发育、促进中枢神经系统的结构发育与功能的建立等均与“碘”直接有关。 相似文献
8.
促性腺激素释放激素(GnRH)是1种在下丘脑-垂体-性腺轴(Hypothalamus-pituitary-gonad,HPG)的活动中发挥关键作用的神经激素。研究采用染色体步移方法,从许氏平鲉的肌肉组织中克隆得到GnRH1、GnRH2和GnRH3共3个基因的启动子序列,长度分别为4,3.5和2.5kb。利用在线生物信息学软件对这3个GnRH基因的启动子进行预测分析,结果表明,3个基因均存在Sp1,Oct-1,C/EBP,CREB,Pit-1,NF-1,Brn,GATA-1,USF和MyoD等转录因子的结合位点,以及糖皮质激素受体(GR),雄激素受体(AR),雌激素受体(ER),黄体酮受体(PR),视黄酸受体(RAR)和视黄醇受体(RXR)等核受体的结合位点,推测其对GnRH的调控起到关键作用。但是甲状腺激素受体(TR)和嗅觉相关的Olf-1的结合位点只在GnRH1和GnRH2基因启动子中发现,而在GnRH3中没有预测出。本研究结果表明许氏平鮋不同类型的GnRH是受不同的机制调控的,从而在生理过程中发挥着不同的作用。 相似文献
9.
《中国海洋大学学报(自然科学版)》2010,(Z1)
为了探讨甲状腺激素受体在大菱鲆(Scophthalmus maximus)体内的表达情况及在细胞水平三碘甲状腺原氨酸(T3)对甲状腺激素受体(TR)表达量的影响,利用荧光定量PCR法检测了大菱鲆8个组织中甲状腺激素受体TRαA、TRβ的表达量,并设计了0,50,75,100和200 nmol/L 5个不同浓度的T3处理大菱鲆肾细胞(SMKC),采用实时荧光定量PCR法测定T3处理后甲状腺激素受体TRαA、TRβ的表达量。结果表明,甲状腺激素受体TRαA、TRβ在大菱鲆不同组织中的表达量各不相同,但两者均在肾脏组织中表达量最高。在不同浓度T3处理后甲状腺激素受体的表达量存在明显的差异,在低浓度条件下,TRαA、TRβmRNA的表达量增加,当T3浓度达到100 nmol/L时,TRαA、TRβmRNA表达量明显降低,说明50,75 nmol/L的T3能够引起细胞中甲状腺激素受体TRαA、TRβ表达量的增加,而100,200 nmol/L的T3会相对抑制细胞中甲状腺激素受体TRαA、TRβ的表达量。 相似文献
10.
采用H.E染色法、Mallory染色法、Heidenhain-Azan(简称HA)法、鱼类脑垂体染色法(简称Jafri)及电镜技术对雌性条斑星鲽Verasper moseri的脑垂体进行了组织学和超微结构的研究,探讨了促性腺激素分泌细胞与性腺发育的关系。结果表明,雌性条斑星鲽脑垂体呈背腹型,由神经垂体和腺垂体两部分组成。神经垂体为一束神经纤维,中间夹杂两种垂体细胞和两种胶质。腺垂体结构复杂,分为前腺垂体(RPD)、中腺垂体(PPD)和后腺垂体(PI),腺垂体内鉴别出6种内分泌细胞。前腺垂体内有3种:催乳激素(PROL)分泌细胞、促肾上腺皮质激素(ACTH)分泌细胞和促甲状腺激素(TSH)分泌细胞;中腺垂体含有生长激素(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;后腺垂体内含有一种促黑色素激素(MSH)分泌细胞。雌性条斑星鲽脑垂体内只发现一种类型的GtH分泌细胞,其内含有大小两种分泌颗粒.同时也研究了垂体中其他细胞的特点。 相似文献
11.
Residues of UV filters used as ultraviolet absorbers in sunscreens, cosmetics and in light protection have been found in surface water and fish. Recently some of them were shown bearing estrogenic activity, however, very little is known about possible adverse effects to aquatic life. Here we investigate whether two UV filters, 4-methylbenzylidene camphor (4-MBC) and 3-benzylidene camphor (3-BC), interfere with the thyroid and sex hormone system during frog metamorphosis. Xenopus laevis tadpoles were exposed to 1, 5 and 50 μg/L of 4-MBC and 3-BC, respectively, for 35 days (NF stage 52–66). The rate of metamorphosis was not affected, and no obvious differences in body and tail length compared to controls were observed. Neither 4-MBC, nor 3-BC led to effects on the sex ratio or gross gonad morphology of X. laevis at stage 66. Our results indicate that these UV filters do not negatively affect the thyroid system and sex ratio of frogs at environmental concentrations. 相似文献
12.
Thyroid hormone is a kind of important hormone which regulates metamorphosis. Its role is well described in amphibian metamorphosis. Thyroid hormones (T3 and T4) have also been demonstrated to play a role in metamorphosis of marine invertebrates. However, the mechanism of thyroid hormone in metamorphosis of marine invertebrates remains unknown. A homolog of vertebrate thyroid hormone receptor (TR) was cloned and identified in abalone Haliotis diversicolor and was named HdTR . The mRNA expressions of HdTR , thyroid peroxidase ( TPO ), thyroid peroxidase 1 ( TPO1 ), idothyronine deiodinase Ⅲ( IDⅢ) and integrin alpha-V ( ITGAV ) had significant diff erence in metamorphosis of H . diversicolor . Metamorphosis rate and mortality rate were significantly diff erent in HdTR RNAi experiment and T3 inducing experiment. In RNAi experiment, ITGAV and CCND1 (cyclin D1) expression of dsRNA HdTR exposing group were significantly lower than those of blank control and negative control. But CTNNB (catenin beta) expression of dsRNA HdTR exposing group was higher than that those of blank control and negative control. ERK (extracellular signal regulated kinases) and PI3K (phosphoinositide-3-kinase) had no significant diff erence in RNAi experiment. Moreover, ITGAV of 1 μmol/L T3 group was significantly lower than that of 0 μmol/L T3 group, PI3K expression of 10 μmol/L T3 group was higher than that of 0 μmol/L T3 group, and the other genes expression had no significant diff erence in T3 inducing experiment. The data of genes expression suggested that CCND1 might be an eff ector gene of TR genomic action, while CTNNB might be regulated by unliganded TR. CCND1 and CTNNB may be involved in cell proliferation of metamorphosis. T3 might regulate the expression level of PI3K via nongenomic way. These results shed light on the mechanism of thyroid hormone in abalone metamorphosis. 相似文献
13.
14.
Mummichogs (Fundulus heteroclitus) from Piles Creeks (PC), New Jersey (a polluted site), are sluggish and show poorer prey capture and predator avoidance than reference fish from Tuckerton (TK). The behavioral dysfunction of the PC fish may be associated with thyroid impairment due to endocrine disruption. In this study, we compared thyroid histology and thyroid hormones in the two populations and determined experimentally whether the polluted environment could alter thyroid hormone levels. PC fish had larger thyroid follicles, greater follicle cell heights, and contained higher plasma thyroxine (T4) levels than TK fish. However, there were no significant differences in either plasma or tissue triiodothyronine (T3). TK fish held in simulated PC environments had higher plasma T4 and lower plasma T3 than field-sampled fish. PC fish held in clean water had lower plasma T4 and T3 than field-sampled fish. In either case, there was no significant difference in tissue T3 content. The contaminants in PC alter thyroid structure and function, which may relate to the behavioral differences between fish from the polluted and reference sites. 相似文献
15.
In teleost sPeCies, it is well accepted that estradiol--l75 (E2 )is generated from ovarian fOl-licles stimulated by pituitary gonadOtropins (GTH) (Nagahama, l987). FUrthermore, E2 canstimulate hepatic vitellngenesis and elevate plasrna yOlk protein precursor vite1lOgenin, totalCa and W levels in several teleosts (KorSgaard and Petersen, l976, l978; Whiteheadet al., l978; Elliott et al., l979; Pertersen et al., l983; Wallace, 1985; tapigliati etal., 1999). On the other hand, many stud… 相似文献
16.
Chunyan Zhao Liang Chi Yongshuang Xiao Bing Li Yunliang Lu Yanting Cui Wenqi Wang Jun Li 《海洋学报(英文版)》2022,41(12):115-122
The brain plays a critical role in controlling reproduction through the hypothalamus-pituitary-gonadal (HPG) axis in vertebrates. Turbot (Scophthalmus maximus) has become an economically important marine fish in Europe and North China. Previous research investigating turbot reproduction has focused on the role of the HPG axis in regulating egg and sperm production. However, the morphology and histology of the organs in the HPG axis have not been studied. In this study, we investigated the morphology and histology of brains in female and male turbot at different stages of gonadal development. The results showed that the brains of both female and male turbot were composed of seven parts that are typical of advanced teleosts: the telencephalon, diencephalon, cerebellum, hypothalamus, pituitary gland, myelencephalon, and olfactory bulbs. The telencephalon was well-developed and contained five distinct lobes, with the contiguous diencephalon at the caudal portion. The torus longitudinales and rostral torus semicircularis of the mesencephalon flattened along the dorsal surface, and the rostral corpus cerebellum was located in the dorsal portion. The actual total brain volume in mature males was significantly greater (p<0.05) than that of females with gonadal development. Notably, the pituitary volume in male turbot significantly increased (p<0.05) from immature to mature stage, but this difference did not occur in females. The data together illustrate a distinct sex difference in the turbot brain during gonadal development, providing insight into their HPG axes. 相似文献
17.
In order to evaluate the involvement of the thyroid gland in reproduction, thyroid functioning was described in female cultivated Japanese eel (Anguilla japonica) in progressive stages of sexual maturation induced by chum salmon pituitary homogenate (SPH) treatment. Serum thyroid hormones, thyroxine (T4) and triiodothyronine (T3) were also measured in each stage. Thyroid gland activity (epithelial cell height) was high before SPH injection (previtellogenic stage), further increasing at the early vitellogenic stage, thereafter decreasing to late vitellogenic and migratory nucleus stages. The profiles of both T3 and T4 changed during vitellogenesis, being high during previtellogenic and early vitellogenic stages, and subsequently declining, thus mimicking thyroid gland activity. These results suggest that the thyroid has relation with eel ovarian development during artificial maturation. 相似文献
18.
应用兔抗血清对抗鱼类和哺乳类促激素及其受体的多克隆抗体对雄性半滑舌鳎脑垂体和精巢进行了免疫组织化学定位.其结果显示GnRHR、LHR和GtH免疫活性定位在不同发育时期的腺垂体和精巢中.GtH免疫阳性细胞的数量和免疫强度随着精巢发育成熟而明显增强.同时还发现睾酮（T）和雄激素受体（AR）在半滑舌鳎精巢中的定位有别于其他鱼类,尤其是雄激素受体（AR）免疫活性在精原细胞中的数量很少.依据这个特点文中还讨论了其可能与精巢发育的关系,同时证明了半滑舌鳎精巢发育像其他硬骨鱼类一样受激素的调控. 相似文献
19.
To investigate the effects of a polychlorinated biphenyl (PCB) mixture (Aroclor 1254) on reproductive neuroendocrine function, male Atlantic croaker (Micropogonias undulatus) were exposed to the PCB mixture in the diet (0.1 mg/100. g body wt/day) for 30 days during gonadal recrudescence. Concentrations of the monoamines (5-hydroxytryptamine (5-HT), dopamine (DA) and norepinephrine (NE)) and their major metabolites (5-hydroxyindolacetic acid, dihydroxyphenylacetic acid and 3-methoxytyramine) were measured in the preoptic-anterior hypothalamus (POAH) and medial and posterior hypothalamus (MPH) using HPLC with electrochemical detection. There was a significant decline in 5-HT and DA concentrations and an increase in their metabolite to parent amine ratios in both the POAH and MPH of Aroclor 1254-exposed fish. In addition, Aroclor 1254 exposure resulted in the loss of the in vitro gonadotropin (GtH) response to stimulation by a luteinizing hormone-releasing hormone analog (LHRHa). The reduced availability of 5-HT in the nerve terminals may be responsible for the loss of pituitary GtH response to stimulation by LHRHa. These results support the hypothesis that Aroclor 1254-induced alterations in pituitary gonadotropin release may be mediated, at least partially, by altered hypothalamic serotonergic activity. 相似文献