鳗鲡繁殖生物学研究Ⅳ．人工催熟过程中下海鳗鲡的GtH分泌活动、性腺发育状况和脑垂体GtH细胞的超显微结构

雌二醇通过正反馈作用能促进脑垂体促性腺激素(GtH)细胞的合成活动,使脑垂体GtH水平显著升高。促黄体素释放激素的类似物(LHRH-A)和利血平(reserpine,RES)能促进脑垂体GtH细胞的分泌活动,使血液中GtH含量显著升高。鲤垂体、人体绒毛膜促性腺激素(HCG)和LHRH—A三种激素混合进行多次注射能诱导雌雄鳗鲡性腺发育成熟,其催熟效果明显优于它们的分别单独多次注射或者鲤鱼脑垂体和HCG的多次注射,表明外源的和内源的促性腺激素对于诱导鳗鲡性腺发育成熟都是重要的。鳗鲡脑垂体GtH细胞超显微结构的观察证实它们在激素诱导性腺发育成熟过程中处于活跃的合成与分泌状态。     

大鳍Hu促性腺激素分泌调控的研究

用非洲鲶鱼促性腺激素放射免疫测定方法测定了Ｃｈａｎｇ科鱼类样品中的促性腺激素含量。用这种方法和鲤鱼促性腺激素β－亚基放射免疫测定法测定大鳍Ｈｕ同一批血清样品结果也相当吻合。通过注射促黄体素释放激素类似物和／或多巴胺的Ｄ２受体拮抗剂地欧酮后,定时取样测定血清促性腺激素含量,证明大鳍Ｈｕ促性腺激素的释放同时受到下丘脑分泌的促性腺激素释放激素和多巴胺的双重调节。但是,多巴胺只能抑制由促性腺激素释放激素诱     

大鳍促性腺激素分泌调控的研究

用非洲鲶鱼促性腺激素放射免疫测定方法测定了科鱼类样品中的促性腺激素含量。用这种方法和鲤鱼促性腺激素β亚基放射免疫测定法测定大鳍同一批血清样品结果也相当吻合。通过注射促黄体素释放激素类似物和／或多巴胺的Ｄ２受体拮抗剂地欧酮后,定时取样测定血清促性腺激素含量,证明大鳍促性腺激素的释放同时受到下丘脑分泌的促性腺激素释放激素和多巴胺的双重调节。但是,多巴胺只能抑制由促性腺激素释放激素诱导的促性腺激素分泌,而不能直接抑制基础的促性腺激素分泌,这与非洲鲶鱼相似而与金鱼和鲤鱼等鲤科鱼类明显不同。     

垂体促性腺激素的生理作用及其分泌的调节

垂体促性腺激素是控制生殖机能的重要环节。对促性腺激素的生理作用及其分泌的调节虽然已有一般的概念,但是受到学科发展的限制,有关促性腺激素的很多方面还是不够清楚的。即使垂体具有两种促性腺激素——促卵泡成熟激素(FSH)和促黄体生成激素(LH)——的说法,看来也要作些补充,通过大白鼠和小白鼠的实验说明催乳激素具有促     

蛙类催产和人工授精方法

一、人工催产 人工健产就是对卵球已成熟的雌蛙注射蛙类的脑垂体、绒毛膜促性腺激素或促黄体素释放激素等含有促性腺激素的物质,促使雌蛙产     

外源激素对雌性黄鳝血清类固醇激素的影响

本文研究了几种外源激素对不同季节的雌性黄鳝血清性类固醇激素的影响。结果表明:鲤鱼垂体匀浆和人绒毛膜促性腺激素均显著蹭加血清类固醇水平,多巴胺拮抗剂domperidone降低血清类固醇水平,鲑鱼促性腺激素释放激素类似物增加血清类固醇水平。这些结果提示:雌鳝促性腺激素分泌亦受促性腺激素释放激素刺激,但多巴胺是否也起促性腺激素释放抑制因子的作用尚不清楚。垂体-性腺轴对外源激素的反应有明显的季节性差异,繁殖季节性腺成熟系数高的鱼反应性最强,繁殖前性腺未成熟期较繁殖后恢复发育期反应快.     

鱼类内分泌学研究的动向

鱼类内分泌学的研究是整个比较内分泌学的重要组成部份。1981年12月在香港举行的第九届国际比较内分泌学学术会议,在下丘脑-脑垂体,神经分泌物,促性腺激素释放激素,生殖内分泌,促性腺激素,甲状腺,肾上腺皮质,生长激素和催乳激素,类固醇激素,性分化,性腺成熟,排卵和产卵,季节性周期和节律,代谢的内分泌调节,钙调节,血管活动激素,前列腺素等专题学术报告和讨论组中,关于鱼类内分泌的研究论文都占相当比例。     

鱼类内分泌学研究的动向

鱼类内分泌学的研究是整个比较内分泌学的重要组成部份。1981年12月在香港举行的第九届国际比较内分泌学学术会议,在下丘脑-脑垂体,神经分泌物,促性腺激素释放激素,生殖内分泌,促性腺激素,甲状腺,肾上腺皮质,生长激素和催乳激素,类固醇激素,性分化,性腺成熟,排卵和产卵,季节性周期和节律,代谢的内分泌调节,钙调节,血管活动激素,前列腺素等专题学术报告和讨论组中,关于鱼类内分泌的研究论文都占相当比例。       

大鼠颌下腺促性腺激素释放激素及其mRNA的免疫组织化学与原位杂交研究

用免疫组织化学及原位杂交法,研究了促性腺激素释放激素及其ｍＲＮＡ在大鼠颌下腺的分布。结果显示,大鼠颌下腺的浆液性腺泡的上皮细胞,各级导管的上皮细胞及副交感神经节细胞均呈促性腺激素释放激素免疫反应阳性,阳性反应物质分布在胞质,胞核呈阴性反应。颌下腺的浆液性腺泡上皮细胞,各级导管上皮细胞同样被检测到很强的促性腺激素释放激素ｍＲＮＡ杂交信号。以上结果提示,大鼠颌下腺能自身合成促性腺激素释放激素,促性腺激素释放激素对消化功能可能有重要调节作用。     

鱼类生殖内分泌学研究的进展及其在渔业生产中的应用

鱼类生殖活动的整个调节过程包括:感觉器官把外界环境的刺激(如温度、光照、降雨等)传送到脑,使下丘脑产生促性腺激素释放激素(GnRH)和促性腺激素释放的抑制因素(GRIF),激发或抑制脑垂体合成和释放促性腺激素(GtH);促性腺激素作用于性腺并促使它分泌     

多囊卵巢综合征猕猴的生殖特性(英文)

多囊卵巢综合征(PCOS)是临床上常见的一种内分泌失调性疾病,也是造成无排卵性不孕的重要原因。对多囊卵巢综合征动物模型的研究有10余年,迄今尚未建立起较为理想的模型动物。该研究的目的在于构建猕猴多囊卵巢综合征动物模型,并分析该模型动物的一些主要生殖特性。将6只成年雌性猕猴(6～10a)平均分成2组:PCOS模型组和对照组。模型组动物的建立方法是:在月经周期的第1、3、5天,分别皮下注射丙酸睾丸酮一次,剂量为3.5mg/kg体重;接着在第7、9、11天,分别肌注人绒毛膜促性腺激素一次,剂量是350IU/kg体重;连续注射2个月经周期。对照组动物注射生理盐水。结果显示:PCOS模型组动物呈现出高血清LH和T,分别为(5.35±0.17)IU/L和(7.58±0.14)ng/mL,而且血清LH/FSH值(5.35/1.30=4.12);模型组动物血清FSH、E2和P的含量与对照组无显著差异。腹部B超扫描结果提示,模型组动物卵巢多囊化。对两组动物进行超排处理后,模型组动物卵巢呈明显的过刺激现象,模型组动物胚胎体外培养的囊胚率为23.53%,显著低于对照组(66.67%)(P<0.05),即用丙酸睾丸酮联合人绒毛膜促性腺激素,能够建立PCOS猕猴模型,该模型动物的一些主要生殖特性与人类PCOS相似。     

Effects of gonadotropins on oocyte maturation and progesterone production by porcine ovarian follicles cultured in vitro

Effects of gonadotropins on the maturation of isolated oocytes and production of progesterone by porcine ovarian follicles from gonadotropin treated gilts have been studied in vitro. The addition of gonadotropins (2 I. U./ml, PMSG, HGC or 2 mg/ml FSH) to the culture medium resulted in increasing the number (84 - 90 %) of isolated oocytes which reached metaphase II. Expansion of the whole cumulus mass was observed only in media containing PMSG, whereas FSH or HCG alone did not cause these marked changes in the cumulus cells. Denudation of the eggs prior to culture gave no significant differences in the maturation rates between oocytes cultured in media with or without gonadotropins. In vitro maturation of follicle-enclosed oocytes took place only in HCG treated animals. Removing the ovary at 15 or 60 minutes after intravenous HCG administration induced oocyte maturation only in 22% and 17% respectively. A sharp increase in the number of oocytes which resume meiosis during follicle culture was observed 4 hours after HCG injection (84 %) and all of the oocytes of the gilts ovariectomized at 8 hours after HCG injection matured during the culture period. The progesterone production of isolated follicles from control gilts (only PMSG injected) increased slowly during a 96-hour culture period (from 48 to 240 ng progesterone/follicle), whereas the secretion of progesterone was drastically increased after a 15 minute interval between HCG injection and ovariectomy (from 42 to 950 ng progesterone/follicle). Follicles removed 24 hours after HCG injection showed a further increase in steroid production (2000 ng progesterone/follicle) and consistently secreted large amounts of progesterone during the culture period.     

Inhibition of follicle-stimulating hormone-induced ovulation by indomethacin in the perfused rat ovary

In isolated, perfused ovaries of rats treated with pregnant mare's serum gonadotropin (PMSG), purified preparations of ovine follicle-stimulating hormone (FSH) (oFSH-211B) and rat FSH (rFSH-I-6), 100 ng/ml, were found to induce ovulations (4.8 +/- 0.9, n = 4, and 6.4 +/- 2.0, n = 5, ovulations per ovary, respectively). Indomethacin (5 micrograms/ml) added to the perfusate inhibited this ovulatory effect and exogenous prostaglandin F2 alpha (PGF2 alpha) (1 microgram/ml), or prostaglandin E2 (PGE2) (0.5 microgram/ml), reversed the blockade. Ovine FSH and rFSH had only a weak stimulatory effect on estradiol release, and only rFSH caused a significant increase in progesterone accumulation. Indomethacin reduced the stimulatory effect of rFSH on progesterone release, and this effect was reversed by PGE2 but not by PGF2 alpha. In a 6-h incubation experiment with preovulatory rat follicles, we tested the biological activity of gonadotropins used to induce oocyte maturation. The concentration of FSH used in the perfusion experiments induced oocyte maturation in more than 88% of the oocytes studied. The data confirm earlier findings that FSH can induce ovulations and show that prostaglandins are involved in this process. The data also indicate that prostaglandins might be involved in the FSH-induced increase of progesterone levels.     

Ovarian effect of periodic episodes of elevated serum follicle stimulating hormone (FSH)

Periodic increases (episodes) of serum follicle stimulating hormone (FSH) were induced for various lengths of time (epochs) by the intraperitoneal injection of synthetic porcine luteinizing hormone releasing hormone (LH-RH) into immature female rats. The effect of the FSH on ovarian weight was evaluated with augmentation by human chorionic gonadotropin (HCG). Eight injections of LH-RH, at hourly intervals, produced increased ovarian weight in all animals; with 6 episodes 67% and with 4 only 33% responded. Increasing the length of the epoch of elevated serum FSH to 10 hours was without added effect. The minimally effective serum FSH level was estimated to be about 1000 ng/ml (RP-1). This concentration was produced by injecting LH-RH at 30 minute intervals over a period of 2 hours and it proved to be effective in increasing ovarian weight 48 hours later. Multiple 3 hour epochs, separated by at least 3 hours, were no more effective than a single epoch. Non augmented ovarian and uterine weights were significantly raised by injection of LH-RH on three consecutive days. The results suggest that a circadian rhythm in gonadotropin output could effectively cause normal ovarian development. Periods of increased pulsatile activity by the pituitary would need to be relatively brief to produce threshold concentration of gonadotropin for a threshold period of time.     

Effects of gonadotropins on follicular development, ovulation, and atresia in the mature guinea pig

The induction of follicular growth, ovulation, and atresia by heterologous gonadotropic preparations was studied late in the reproductive cycle of the adult female guinea pig. Human chorionic gonadotropin (HCG) administration (10 IU) 12 days following the first signs of opening of the vaginal membrane was found to stimulate ovulation within 24 h in all animals studied, as evidenced by recovery of ova from their oviducts as well as the presence of postovulatory follicles in their ovaries. Histologically, ovaries of animals receiving HCG exhibited atretic changes in most of the follicles smaller than 999 micrometer in diameter. Pregnant mares serum gonadotropin (PMSG, 10 IU) administered on days 9 and 10 of the cycle was not sufficient to stimulate ovulation in this species although histological changes in the follicular complement were observed. Administration of PMSG prior to the HCG appeared to have an inhibitory effect on ovulation induction. Follicles luteinizing with entrapped ova were seen in all groups receiving exogenous gonadotropin, although they were most prevalent in the animals receiving the maximum total gonadotropin doses (i.e. PMSG + HCG).     

The effect of exogenous hormone treatment on spermiation and vitellogenesis in the grey mullet, Mugil cephalus L.

The effects of mammalian gonadotropins, methyltestosterone and partially purified salmon gonadotropin on spermiation and oocyte maturation were studied in adult grey mullet. Methyltestosterone was a potent spermiating agent in both prespawning and spawning trials. The most effective dose was 5 mg/100 g body weight. Human chorionic gonadotropin (HCG) was moderately effective at a dose rate of 20 IU/100 g body weight. Both hormones blocked resorption of milt in captive animals. The HCG, FSH/LH combination, Synahorin+mullet pituitary homogenate, and partially purified salmon gonadotropin were equally effective, at the doses used, in inducing oocyte maturation and preventing onset of atrophy before completion of vitellogenesis. Atrophy occurred in all experimental fish at mean oocyte diameter of 750 μ. The significance of this finding is discussed. (Oceanic Institute Contribution No. 98).     

The influence of serum and gonadotropins on in vitro maturation and fertilization of bovine oocytes

The influence of estrous cow serum (ECS) or fetal calf serum (FCS) and their interaction with gonadotropins on in vitro bovine maturation and fertilization was evaluated. The addition of ECS or FCS to the medium significantly increased the percentage of oocyte maturation over that of Ham's F-10 medium alone (P<0.05). The addition of follicle stimulating hormone (FSH), human chorionic gonadotropin (hCG) or of FSH plus hCG to the medium provided no advantage in maturation over serum alone. However, FSH plus HCG added to the maturation medium significantly improved the frequency of pronucleus formation in both groups compared with a medium to which no gonadotropins were added (P<0.05). Both ECS and FCS (as medium supplements) promoted oocyte maturation. Although the addition of a combination of FSH plus hCG to the medium did not increase the rate of oocyte maturation, it did contribute to the high incidence of subsequent pronucleus formation.     

乙炔基雌二醇(EE2)对雄性黄颡鱼GtH3个亚基基因表达的影响

为研究乙炔基雌二醇(EE2)是否能影响雄性黄颡鱼(Pelteobagrus fulvidraco)垂体中促性腺激素3个亚基基因的表达,从而干扰FSH和LH的分泌,研究采用末端快速扩增(RACE)的方法在黄颡鱼垂体中克隆了促性腺激素的2个亚基(FSH和LH)的全长cDNA,对其组织表达模式和雌雄性垂体中的季节表达模式进行了研究;另外,研究还用100 ng/L的EE2对雄性黄颡鱼(2龄)进行了28d的暴露处理。结果发现,黄颡鱼FSH cDNA全长528 bp, ORF为399 bp,编码132个氨基酸; LH全长为870 bp, ORF为417 bp,编码138个氨基酸。序列分析结果表明,黄颡鱼FSH含有一个17氨基酸的信号肽, 2个保守的N-糖基化位点和13个半胱氨酸残基,而LH含有一个18个氨基酸的信号肽, 1个N-糖基化位点和12个半胱氨酸残基,与其他鲶形目鱼类极其相似。进化分析显示,黄颡鱼FSH和LH与鲶形目的鱼类进化关系较近。组织分布结果发现,黄颡鱼3亚基均仅在垂体中表达。季节表达模式结果表明,雌雄黄颡鱼GtH和LH表达水平在5月份左右达到最高,随后降低; FSH在雌性的表达模式与GtH和LH相同,而在雄性, FSH的表达没有明显变化。半定量RT-PCR结果显示, 100 ng/L的EE2能显著抑制黄颡鱼促性腺激素3个亚基基因的表达。研究认为, EE2抑制黄颡鱼雄性垂体FSH和LH的分泌,可能阻碍其正常的精子发生、精子成熟和排精过程,从而影响其正常的繁殖和发育。       

The effect of indomethacin on HMG-HCG induced ovulation in the rhesus monkey

The investigation was designed to study the influence of indomethacin on gonadotropin induced ovulation in the rhesus monkey. Six mature female monkeys were treated with HMG-HCG for at least 2 control ovulatory cycles at dosage levels adjusted to induce ovulation while avoiding superovulation. Ovulation was confirmed by observation of the ovaries for fresh ovulation points at laparotomy. Following establishment of an appropriate dosage schedule, treatment was begun with indomethacin (5 mg/kg/day) starting 5 days prior to HCG and continuing to the time of laparotomy. In a second treatment cycle, indomethacin was administered at a dose of 5 mg/kg b.i.d. together with the established dose of HMG-HCG. Ovarian inspection was carried out as in the control cycles. Venous blood was obtained on treatment days 4, 7, 10 and 11 for determination of serum estrone, estradiol and progesterone. Indomethacin administration resulted in ovulation inhibition at a dose of 10 mg/kg/day when ovulation inducing doses of gonadotropins were administered. Peripheral blood steroid levels suggest that follicle maturation and estrogen production are unimpaired by indomethacin. These findings indicate that the ovarian synthesis of prostaglandin may be essential in the process of ovulation.     

Superovulation using recombinant human FSH and ultrasound-guided transabdominal follicular aspiration in baboon (Papio anubis)

The response of baboon females to a modified human ovarian stimulation protocol incorporating start of pituitary suppression in the luteal phase of the cycle with a GnRH agonist (GnRHa) and recombinant human FSH (rhFSH) was studied. A long-acting GnRHa implant supplying goserelin acetate was administered s.c. to six adult female baboons experiencing regular menstrual cycles (33–34 days) on days 22–24 of the cycle. Follicular development was monitored by transabdominal ultrasonography and serum levels of E2 and progesterone (P4) and rhFSH were determined by ELISA. Menses occurred 9–10 days after GnRHa administration. Daily i.m. administration of 75 IU rhFSH commenced 9–10 days after menses and continued for 9–10 days. When most follicles were ≥5 mm diameter and serum E2 had reached its maximum level, 2000 IU hCG was administered i.m. to induce follicle maturation. Transabdominal ultrasound-guided follicular aspiration of follicles ≥2 mm diameter was performed 30–34 h after hCG administration.

One baboon did not show an adequate response to rhFSH stimulation. This animal did not receive further treatment and no data for it are presented. The number of follicles aspirated was 21±4 and 17.2±3.8 oocytes were recovered per animal with an average recovery rate of 82% (86/105). The number of oocytes collected from five animals were 14, 21, 16, 15, and 20 (n=86). Most of the oocytes recovered were in metaphase II and 3 h after recovery 91% (78/86) were considered suitable for in vitro fertilization. It was concluded that recombinant human FSH can successfully induce follicular recruitment and oocyte maturation in baboon females during pituitary suppression with a GnRHa