促黄体素释放激素类似物和地欧酮诱导鲇排卵和产卵

以珠江和辽河流域的鲇（Silurus asotus)为研究对象，在室内进行了不同组合的激素和药物注射实验，结果表明，注射促黄体素释放激素类似物（LHRH－A）和多巴胺拮抗物地欧酮（DOM）药物组合（LHRH－A＋DOM），剂量为（10ug 5mg)/kg鱼体重，能快速而大量诱导鲇血清促性腺激素（GtH)水平的升高，进而诱导产卵，产卵率为90％，显著高于其他实验组，采用LHRH－A＋DOM药物组合对2926组鲇进行了人工催产，注射剂量为（7ug 5mg)/kg，鱼体重，平均催产率为70％，最高80％，获得鱼苗207万尾。     

介绍效果更好的鱼类催产合剂——高效鱼类催产合剂2号和3号

鱼类促性腺激素(GtH)的分泌和生殖活动已经证明为双重的神经内分泌系统所调节，即促性腺激素释放激素(GnRH)刺激GtH分泌和多巴胺作为促性腺激素释放的抑制因素(GRIF)抑制GnRH的作用以及GtH的自行释放。我们先前对养殖鱼类的研究已证明多巴胺受体的拮抗物(如pimozide，PIM)，排除剂(如reserpine，RES)和多巴胺合成抑制剂都能显著增强LRH-A诱导GtH分泌和排卵的作用。     

高效新型鱼类催产合剂介绍

<正> 近年来对鱼类生殖生理的研究已经证明:(1)鱼类脑垂体促性腺激素(GtH)的分泌活动既受到下丘脑分泌的促性腺激素释放激素(GnRH)的促进,又受到下丘脑产生的促性腺激素释放的抑制因素(GRIF)的抑制。(2)下丘脑神经分泌细胞产生的多巴胺具有GRIF的作用,它既能直接抑制脑垂体GtH细胞的分泌活动,亦能抑制GnRH促进GtH的分泌作用。(3)多巴胺的拮抗物或合成抑制剂能消除多巴胺对鱼脑垂     

Pimozide和LRH——A对鲢鱼的排卵作用

<正> 近年来Chang等(1982,1983)在金鱼上的研究证明,多巴胺对于调节促性腺激素(GTH)本身的释放具有抑制作用。Chang和Peter(1983)发现Pimozide(一种多巴胺拮抗物)在金鱼中,能极大地加强促黄体生成素释放激素类似物(LRH—A)     

长吻鮠人工催产及脑垂体促性腺激素细胞的超微结构的变化

通过对催产和未催产的长吻鮠脑垂体中腺垂体促性腺激素分泌细胞（ＧＴＨ 细胞） 的分泌活动分析,证实了用促黄体素释放激素类似物（ＬＲＨ－ Ａ） ５０μｇｋｇ 加ＤＯＭ５ｍｇｋｇ 混合注射催产长吻鮠,能有效地促使ＧＴＨ细胞分泌促性腺激素,诱导卵母细胞成熟和排卵,催产效果显著。超微结构的进一步观察,揭示了长吻鮠脑垂体ＧＴＨ 细胞中存在两种分泌颗粒,即分泌小球,直径１２００～２０００ｎｍ ,电子密度低;分泌颗粒直径３００ ～５００ｎｍ ,电子密度高。分泌小球释放与卵母细胞的发育成熟有关,分泌颗粒的释放则与排卵相关。     

鱼类下丘脑—垂体神经分泌系统功能综述

鱼类的生殖是受环境影响的。感觉器官把外界环境的刺激(如温度、光照等)传送到脑,使下丘脑分泌促性腺激素释放激素(GnRH),激发脑垂体分泌促性腺激素作用于性腺并促使性腺分泌性甾类激素,以促使性腺发育成熟及排出精子和卵子。     

促性腺激素释放激素类似物和左旋多巴对秀丽高原鳅体长、体重和卵巢发育的影响

秀丽高原鳅(Triplophysa venusta)为云南特有鱼类,为阐明促性腺激素释放激素类似物和左旋多巴对秀丽高原鳅体长、体重和卵巢发育的影响,本实验采用生物化学等技术,研究了促性腺激素释放激素类似物(GnRH-a,0.1 mg/kg/2周,共注射4次)和左旋多巴(L-dopa,100 mg/kg/2周,共注射4次)对体长、体重和卵巢发育的影响,以期为秀丽高原鳅人工繁育提供理论依据.结果表明:两种外源激素处理组和对照组间体长、体重变化均无显著差异,两种外源激素对秀丽高原鳅体长和体重的影响不明显;由于个体成熟度差异较大,有的个体卵巢尚未发育成熟,故无法进行分区的组间比较,但对少数成熟个体进行了卵巢腺发育的特征和组织学分期.     

长吻Wei人工催产及脑垂体促性腺激素细胞的超微结构的变化

通过对催产和未催产的长吻Ｗｅ８脑垂体中腺垂体促性腺激素分泌细胞（ＧＴＨ细胞）的分泌活动分析,证实了用促黄体素释放激素类似物（ＬＲＨ－Ａ）５０μｇ／ｋｇ加ＤＯＭ５ｍｇ／ｋｇ混合注射催产物吻Ｗｅｉ,能有效地促使ＧＴＨ细胞分泌促性细胞激素,诱导卵母细胞成熟和排卵,催产效果显著,超微结构的进一步观察,揭示了长吻Ｗｅｉ脑垂体ＧＴＨ细胞中存在两种分泌颗粒,即分泌小球,直径１２００－２０００ｎｍ,电子密度低;分     

高效鱼类催产合剂2号对主要养殖鱼类的催产效果

高效鱼类催产合剂2号由多巴胺拮抗物中的DOM和促黄体释放激素类似物(LRH-A_2)组成,能显著增强脑下垂体(PG)释放促性腺激素(GTH)和诱导排卵作用。 自1989年以来,我们应用高效鱼类催产合剂2号对青、草、鲢、鳙和鳜鱼进行了催产(催情)试验,效果显著。现总结如下。1 催产剂来源与制备 高效鱼类催产合剂2号由中山大学生物系鱼类研究室生殖内分泌生理教研室林浩然教授等研制而成,由宁波市激素制品厂生产、     

激素缓释制剂诱导海水养殖鱼类性腺发育成熟与生殖行为的研究进展

综述促性腺素释放激素类似物（GnRH-a)缓释制剂（SRDS），人绒毛膜促性腺激素（HCG）SRDS，类固醇激素SRDS；雄烯二酮（ADSD）和17a-甲基睾丸酮（MT），以及鲤垂体匀浆（CPE）混合SRDS诱导海水养殖鱼类性腺发育成熟和生殖行为的效果，认为采用GnRH-a SRDS处理性腺发育良好的鲈形目鱼类和鲆鲽鱼类，可以显著提高血液促性腺激素（GtH)水平，且持续时间长，诱导排卵成功，HCG乳胶SRDS可诱导日本鳗鲡（Anguila japonicus)血液GtH持续 升高，性成熟系数明显升高并且性腺发育成熟；HCG和CPE水／油／水（W／O／W）复乳SRDS对日本鳗鲡的催熟效果显著，采用ADSD和MT SRDS SRDS可成功诱导日本鳗鲡性腺成熟与排卵。     

LHRH-A、DA对施氏鲟脑垂体碎片释放GtH的影响

为了探讨在古老的软骨硬鳞鱼中促性腺激素(GtH)的双重内分泌调节作用,本实验设计用离体灌流的方法研究促黄体素释放激素类似物(LHRH-A)和多巴胺(DA)对施氏鲟脑垂体碎片分泌GtH的影响。引入10、100和1 000 nmol/L 3个浓度的LHRH-A对施氏鲟脑垂体碎片3次脉冲式刺激实验;每次间隔1 h,持续5 min,研究不同剂量LHRH-A对鲟鱼脑垂体释放GtH的作用;用200 nmol/L DA对施氏鲟脑垂体碎片持续2 h灌流后引入5 min的1 000nmol/L LHRH-A刺激实验,研究DA如何抑制鲟鱼脑垂体释放GtH。每5 min收集一管灌流液,用放射免疫测定法(RIA)检测灌流液中GtH的含量。结果显示,低剂量LHRH-A随着刺激引入脑垂体释放GtH出现波浪式的增加,中、高剂量出现释放延后现象。LHRH-A在10nmol/L到1 000 nmol/L范围内对刺激脑垂体释放GtH没有剂量依存关系。DA对施氏鲟脑垂体碎片GtH的分泌没有显著影响,但是可以抑制LHRH-A引起的GtH分泌,即DA不能抑制施氏鲟GtH的基础分泌,而只能抑制LHRH-A诱导的GtH分泌。研究结果证明,在高等硬骨鱼类中存在的双重神经内分泌调节在古老的鲟鱼中也存在。     

Effects of exogenous neurohormone, gonadotropin (GtH) and dopaminergic drugs on the serum GtH content and ovulatory responsiveness of wild catfish, Silurus asotus (Linnaeus, 1758)

Wild female catfish Silurus asotus (Linnaeus, 1758) were injected with domperidone (DOM) alone, [d ‐Ala⁶, Pro⁹ Net]‐luteinizing hormone‐releasing hormone (LHRH‐A) alone once or twice, LHRH‐A plus DOM once or twice simultaneously at 6‐h intervals, LHRH‐A plus carp pituitary extract (CPE) twice simultaneously at 6‐h intervals and LHRH‐A plus human chorionic gonadotropin (HCG) twice simultaneously 6 h apart respectively. The results indicated that injection of LHRH‐A at a dosage of 0.01–0.02 μg g^?1 body weight (BWt) alone induced a low but significant increase in serum gonadotropin (GtH) (P<0.05) and resulted in a very low ovulation rate, while DOM at a dosage of 5 μg g^?1 BWt alone did not induce an increase in the serum GtH levels and ovulation; in contrast, LHRH‐A at a dosage of 0.01 μg g^?1 BWt plus DOM at a dosage of 5 μg g^?1 BWt (termed the Linpe technique) increased the serum GtH (P<0.05) significantly and induced an ovulatory rate of 100%, while LHRH‐A plus CPE or HCG resulted in an increase in the serum GtH (P<0.05) and high ovulatory rate, although the latency period was longer when fish were given LHRH‐A plus HCG or CPE.     

Dopamine inhibits gonadotropin secretion in the Chinese loach (Paramisgurnus dabryanus)

The effects of dopamine on gonadotropin (GtH) secretion in sexually mature Chinese loach were investigated. Spontaneous secretion of GtH was inhibited within 1 h following an intramuscular injection of dopamine (100 g/g body wt). Similarly, dopamine (50 and 100 g/g body wt) caused a significant reduction in serum GtH in fish with elevated GtH levels as a result of pretreatment with gonadotropin-releasing hormone (GnRH) analogs either alone or in combination with the dopamine receptor antagonist domperidone. In summary, the present study provides direct evidence that dopamine functions as a gonadotropin-release inhibitory factor in the Chinese loach by blocking spontaneous and GnRH-stimulated GtH release.     

异齿裂腹鱼人工规模化繁殖技术研究

2010年4～6月,对野生异齿裂腹鱼(Schizothorax o' connori)人工规模化繁殖技术进行研究,并初步进行产后亲鱼恢复培养技术研究.对108尾雌鱼进行干法人工授精,共采卵104万多粒,孵出仔鱼62万多尾.其中45尾雌亲鱼自然成熟,共采卵46.8万多粒,平均受精率和孵化率低于人工催产雌鱼卵.人工催产83...     

Gonadotropin‐releasing hormone analogue multiple injection potentially accelerated testicular maturation of male yellow catfish (Pelteobagrus fluvidraco,Richardson) in captivity

The potential for accelerating testicular development and final maturation of adult male yellow catfish (Pelteobagrus fluvidraco, Richardson) in captivity was evaluated by using gonadotropin‐releasing hormone analogue (GnRHa) multiple injection, and its possible regulatory mechanism was explored by measurements of luteinizing hormone (LH) and steroid levels. The results showed that GnRHa multiple injection increased gonad‐somatic index (GSI), the sperm count and the milt‐testis index (MTI) and promoted the larvae production by elevated rates of fertilization and hatching, and lowered the rate of deformed larvae. Meanwhile GnRHa treatment decreased the percentages of spermatogonia and spermatocytes, increased the relative sperm density (RSD) and percentages of spermatids and spermatozoa (STZ), suggesting GnRHa treatment could accelerate meiotic division and enhance the formation of spermatids andSTZ. Moreover, pituitary and serum LH, as well as serum T levels were increased after GnRHa multiple injection. Taken together, the present study demonstrated GnRHa multiple injection successfully accelerated the testicular development and maturation of male yellow catfish, which was mediated by the increase in serum LH and T levels that further mediated biological and histological changes of testis. Therefore, GnRHa multiple injection could be a valuable method to induce precocious testicular maturation of adult yellow catfish with gonadal developmental arrest in captivity.     

Characterization of molecular variants of GnRH, induction of spermiation and sex reversal using salmon GnRH-A and domperidone in the protogynous diandric fish, Synbranchus marmoratus Bloch, (Teleostei, Synbranchidae)

This paper studies the molecular variants of gonadotropin-releasing hormone (GnRH) present in the brain of the protogynous swamp eel, Synbranchus marmoratus, and the effects of the administration of salmon GnRH analogue (sGnRH-A) and the dopamine receptor antagonist, domperidone (DOM) on final maturation and gamete release in this species. Evidence for the presence of two GnRH variants, sGnRH and cIIGnRH were obtained by reverse phase high-pressure liquid chromatography (RP-HPLC) and radioimmunoassay with different antisera. The effects of treatment with sGnRH-A+DOM were checked by three ways: oocyte and milt release by stripping, histological analysis of the gonadal tissue, and androgen serum levels at different times throughout the experiment. In males, spermiation was induced after three weeks of treatment. In the female group, sGnRH-A+DOM did not induce ovulation at the end of the experiment. Histological analysis of the gonads from the female group showed evidence of sex reversal. All the treated fish had elevated androgen serum levels from the third week, with respect to control fish. In all cases, serum estradiol levels were undetectable. These results suggest that treatment with sGnRH analog and DOM induce sex reversal in female and spermiation in males. This revised version was published online in July 2006 with corrections to the Cover Date.     

云南盘(绚)人工繁殖及胚胎发育初步观察

采用催产素绒毛膜促性腺激素(human chorionic gonadotrophin,HCG)、促黄体素释放激素A2(luteinizing hormone releasing hormone A2,LHRH-A2)和地欧酮(domperidone,DOM)对性腺发育良好的野生云南盘(绚)(Discogobio yunnanensis)进行人工催产,干法授精.利用体视镜观察早期胚胎发育过程,并详细记录了各发育阶段的形态特征及发育时序.结果显示,云南盘(绚)成熟卵圆形、黄绿色、弱粘性,卵径平均2.1 mm.受精后卵迅速吸水膨胀,卵膜外径平均3.29 mm.在水温17 ～19℃条件下,胚胎发育历时168 h 30 min,胚胎发育过程可划分为受精卵、卵裂、囊胚、原肠胚、神经胚和器官发生6个阶段,共27个分期.初孵仔鱼平均体全长为7.16 mm,平均体质量为0.012 g,初孵仔鱼口凹形成,鳃循环明显,泄殖孔处可见输尿管,残余卵黄囊较大.     

Induction of ovulation in the loach (Paramisgurnus dabryanus) using pimozide and [D-Ala6, Pro9-N-ethylamide]-LHRH

The effects of intraperitoneal injections of [D-Ala⁶, Pro⁹-N-ethylaminde]-luteinizing hormone releasing hormone (LHRH-A) and pimozide (PIM), a dopamine receptor antagonist, on ovulation in loach were investigated. LHRH-A and PIM administered separately were ineffective in inducing ovulation. However, injections of PIM and LHRH-A simultaneously or the injection of PIM 2.5–3 h prior to LHRH-A were highly effective means of inducing ovulation. The simultaneous injection of PIM (1.0 μg/g body wt) and LHRH-A (0.05 μg/g body wt) resulted in a greater ovulatory response than injection of carp pituitary extract (1 pituitary/fish).     

Broodstock Rearing and Controlled Reproduction of Reeves Shad Tenualosa reevesii

Reeves shad Tenualosa reevesii is one of China's best known anadromous fish, but is presently on the verge of extinction. There is an urgent need for conservation of this species through artificial reproduction and culture. In this study, shad broodstock were held in captivity then were induced to spawn with serial injections of luteinizing hormone-releasing hormone analogue (LHRHa) following GtH priming by implantations of 17-methytestosterone (T) combined with environmental manipulations. Induced maturation of 4, 5, and 6-year-old females reached 83.3%, 87.5%, and 100%, respectively, while fish in control treatments remained immature. During the gonadal development priming period, mean serum 17-estradiol levels in the T treatment were significantly higher than the LHRHa treatment and control fish. Gonadal development of females was suppressed when their mesenteric fat index was below 1.5% by April. The effective accumulating temperatures for female and male maturation were 3,995 ± 31.4 C/d and 2,278 ± 8.9 C/d, respectively. Two injections of LHRHa in combination with domperidone (DOM) and environmental regulations were effective in inducing ovulation. About 800,000 fertilized ova were obtained (fertilization 75%) in 1995, and 5,000 fry were hatched in 1996. These results are an important step to develop shad culture and save this endangered species.