脑血管紧张素对黄体生成激素分泌的影响

脑内存在一个独立而完整的肾素－血管紧张素系统。血管紧张素Ⅱ对ＬＨ分泌的调节作用是：（１）脑内外源ＡⅡ对ＬＨ分泌的调节与动物体内性类固醇激素水平有关。去卵巢动物ＡⅡ可以抑制ＬＨ分泌,去卵巢用雌激素处理动物ＡⅡ不影响ＬＨ的分泌,去卵巢用雌、孕激素处理的动物ＡⅡ则可刺激ＬＨ分泌;（２）脑内内源ＡⅡ参与调节大鼠动情前期ＬＨ峰;（３）ＡⅡ对ＬＨ分泌的调节可能是通过ＬＨ－ＲＨ和去甲肾上腺素的作用。     

雄性猕猴血清中促黄体素的分泌水平

本文采用促黄体素（ＬＨ）体外生物测定法，对不同年龄组雄性猴血清中促黄体素分泌水平进行了分析。结果表明：幼年组为５．４±１．７ｎｇ／ｍｌ，成年组为４５．６±１２．８ｎｇ／ｍｌ，老年组为６９．２±２１．５ｎｇ／ｍｌ。提示雄性猕猴ＬＨ分泌模式与人很相似。     

新生大鼠下丘脑培养细胞LH—RH免疫组化观察

用新生大鼠下丘脑细胞进行全外细胞培养,观察下丘脑神经元的生长分化,并对细胞培养,观察了下丘脑神经元的生长分化,并对培养的下丘脑细胞作了ＬＨ－ＲＨ和ＮＳＥ免疫组化观察。结果显示：新生大鼠下丘脑神经细胞可在体外生长发育,对ＬＨ－ＲＨ和ＮＳＥ均呈阳性免疫反应。ＬＨ－ＲＨ免疫组化阳性细胞的图像分析表明,细胞平均光密度和积分光密度在培养早期较低。至第７天时明显增加,以后随培养时间延长又逐渐下降。提示体外培养     

GK糖尿病大鼠生物学特性观察

目的了解2型糖尿病模型GK大鼠生长曲线、主要脏器重量、糖代谢等生物学特性,评价GK大鼠葡萄糖刺激的胰岛素分泌能力。方法采用51只雄性GK大鼠及15只年龄性别匹配的Wistar大鼠作为研究对象。测定13周龄GK、Wistar大鼠空腹血糖、23周龄GK大鼠空腹及随机血糖。随访GK及Wistar大鼠生长曲线,34～46周龄期间血糖、糖化血红蛋白。46周龄时行腹腔葡萄糖耐量实验（IPGTT）,计算相关参数评价β细胞葡萄糖刺激的胰岛素分泌能力;之后处死大鼠,脏器称重。比较GK及Wistar大鼠间上述各指标差异。结果13周龄GK大鼠空腹血糖4．74±0．41mmol／L,对照Wistar大鼠1．85±0．44mmol／L（P〈0．001）。23周龄GK大鼠空腹血糖7．88±1．96mmol／L,随机血糖9．91±3．52～13．46±4．13mmol／L。7～20及34～45周龄期间GK大鼠体重高于对照Wistar大鼠（P〈0．05）,46周龄时无显著性差异。34～45周龄期间GK大鼠空腹血糖、进食后血糖、HbAlc均高于对照Wistar大鼠（P〈0．05）。IPGTT曲线下面积分析示GK大鼠胰岛素曲线下面积（AUCi）、葡萄糖曲线下面积（AUCg）高于对照Wistar大鼠,胰岛素与葡萄糖曲线下面积比值（AUCi／AUCg）低于对照Wistar大鼠,差异均有显著性（P〈0．05）。GK大鼠肾脏重量高于对照Wistar大鼠（P〈0．05）,余主要脏器重量差异无显著性。结论GK大鼠空腹血糖、进食后血糖、HbAlc水平升高,葡萄糖刺激的胰岛素分泌能力（GSIS）减退,葡萄糖刺激后胰岛素分泌早期相消失,晚期相代偿性增加,具有2型糖尿病特点;体重、血糖等生物学特性稳定。     

人参对大鼠胃G细胞、D细胞影响的免疫组织化学观察

本文应用免疫组织化学PAP方法观察大鼠胃G细胞、D细胞的分布和形态特征,以及人参对胃G细胞、D细胞免疫细胞化学活性的影响。用细胞显微分光光度计检测了服用人参的G细胞、D细胞免疫反应阳性面积及光密度。检测结果表明,人参能使大鼠胃G细胞、D细胞增大,增加G细胞中胃泌素的含量和D细胞中生长抑素的含量。本文的结果提示,人参对大鼠胃G细胞和D细胞的形态及分泌活动有调节性影响。     

头孢曲松神经保护作用的研究

目的：探讨头孢曲松通过抑炎通路发挥神经保护作用的机制。方法：45只雄性sD大鼠,随机分为3组（n=15）,预处理组在大鼠大脑中动脉阻断（MCAo）前5d每日给予腹腔注射头孢曲松缓冲液（200mg／kg）,观察局灶性脑缺血2h再灌注24h后,各组间大鼠神经行为学评分、脑梗死容积变化、小胶质细胞和IL-1β的数量变化。结果：再灌注24h后,头孢曲松预处理组可改善大鼠神经行为学评分和脑梗死面积（P〈0．05）,小胶质细胞活化数量减少（P〈0．05）,ELISA检测IL-1β分泌数量有显著下降趋势,但无统计学差异（P=0．18）。结论：头孢曲松可以部分抑制小胶质细胞活化,减少IL-1β释放发挥神经保护作用。     

头孢曲松神经保护作用的研究

目的:探讨头孢曲松通过抑炎通路发挥神经保护作用的机制。方法:45只雄性SD大鼠,随机分为3组(n=15),预处理组在大鼠大脑中动脉阻断(MCAO)前5 d每日给予腹腔注射头孢曲松缓冲液(200 mg/kg),观察局灶性脑缺血2 h再灌注24 h后,各组间大鼠神经行为学评分、脑梗死容积变化、小胶质细胞和IL-1β的数量变化。结果:再灌注24 h后,头孢曲松预处理组可改善大鼠神经行为学评分和脑梗死面积(P<0.05),小胶质细胞活化数量减少(P<0.05),ELISA检测IL-1β分泌数量有显著下降趋势,但无统计学差异(P=0.18)。结论:头孢曲松可以部分抑制小胶质细胞活化,减少IL-1β释放发挥神经保护作用。     

实验性胃肠道功能紊乱症G、D细胞的变化及其意义

探讨G细胞（分泌Gas）、D细胞（分泌SST）与胃肠道功能紊乱发生的关系。用抗－Gas、抗－SST的多克隆抗体和免疫组织化学技术标记胃窦、十二指肠粘膜G、D细胞,运用医学图象分析系统（MIPS）对G、D细胞进行定量分析,并用四君子汤反证,实验表明胃肠道功能紊乱模型大鼠与正常对照组相比,胃窦、十二指肠粘膜G、D细胞数均减少（P＜0.05）,D细胞面积缩小（P＜0.05）,G细胞灰度值增高（P＜0.05）,G／D细胞数和细胞面积比值均增高（P＜0.05）。经四君子汤预防和治疗的胃肠道功能紊乱模型大鼠,G、D细胞数有所增加,D细胞面明显增大,G细胞灰度值、G／D细胞数和细胞面积比值均接近或略低于正常。自然恢复大鼠也有一定程度的改善。但也经四君子汤预防和治疗的大鼠相比有显差异。研究结果从形态学上揭示D细胞分泌SST亢进、G细胞释放Gas不足、G／D细胞比值失调,是导致胃肠道功能紊乱症发生的一个重要病理机制。     

白细胞介素对大鼠离体垂体前叶细胞增殖的影响

本工作采用大鼠垂体前叶（ＡＰ）细胞原代培养方法,以３ＨＴｄＲ掺入率反映细胞增殖水平,研究了ＩＬ１和ＩＬ６对ＡＰ细胞增殖的影响。结果表明：（１）ＩＬ１（１－１００ｎｇ／ｍｌ）促进雄性大鼠和雌性大鼠ＡＰ细胞的增殖。（２）低浓度的ＩＬ６（０．１ｎｇ／ｍｌ）抑制雄性大鼠的ＡＰ细胞的增殖,而较高浓度的ＩＬ６（１－１０ｎｇ／ｍｌ）则表现为刺激作用。（３）ＩＬ６（０．１－１０ｎｇ／ｍｌ）促进雌性大鼠ＡＰ细胞的增殖。上述结果说明ＩＬ１和ＩＬ６除直接调控ＡＰ细胞的分泌外,也参与调节ＡＰ细胞增殖活动。     

大鼠卵巢促黄体激素／人绒毛膜促性腺激素受体cDNA的克隆和在…

促黄体激素／人绒毛膜促性腺激素受体（ＬＨ／ｈＣＦ ｒｅｃｅｐｔｏｒ）是一种与蛋白偶联的糖蛋白。本文报道了从大鼠卵巢ｃＤＮＡ库中筛选ＬＨ／ｈＣＧ受体ｃＤＮＡ及其在昆虫细胞中的高效表达。ＬＨ／ｈＣＧ受体ｃＤＮＡ全长２４０３ｂｐ,编码受体信号肽和成熟受体６７４个氨基酸。用多角体病毒表达载体ｐＶＬ１３９３,ＬＨ／ｈＣＧ受体ｃＤＮＡ在昆虫细胞中得到高效表达。在非还原和还原条件下的ＳＤＳ－ＰＡＧＥ分析显示,用     

酪氨酸对男子血清促性腺激素和睾酮浓度的影响

给成年男子(n=5)口服酪氨酸300mg/日,共6天,第四天肌注 LRH-A 150μg/人,用RIA 法测定其血清 LH、FSH 和睾酮浓度。与对照组(n=5)相比,酪氨酸对 LH 和 FSH 的基础水平和 LRH-A 诱发的 LH 峰和 FSH 峰均无明显影响。睾酮的基础水平稍有升高,而酪氨酸对 LRH-A 引起的睾酮水平升高有明显的抑制作用。结果提示,酪氨酸可不通过垂体而直接作用于睾丸以影响睾酮的分泌。     

介绍一种LHRH调节LH分泌的离体模型—分散垂体细胞灌流技术

成年雄性 SD 大鼠断头后分离出垂体前叶(anterior pituitary,AP)。用胰蛋白酶消化和机械分散制备 AP 细胞(成活率大于95%)。分散的细胞悬液与生物凝胶混合后装上灌流柱,然后用 M199溶液连续灌流24h 以上。每间隔1~h 给予一次6min 的 LHRH 脉冲式刺激。细胞在此灌流过程中有一个稳定的基础 LH 分泌水平。LHRH 刺激能迅速引起 LH 分泌。对同一剂量 LHRH 的多次刺激可产生相同的 LH 脉冲。在一定的 LHRH 浓度范围内(1×10~(-10)_1×10~(-7)mol/L),LH 分泌与 LHRH 的剂量-效应曲线呈线性。实验结果表明,连续灌流分散的 AP 细胞的技术,优于单层细胞培养和组织块灌流等其他方法,是一种较为理想的研究LHRH 调节 LH 分泌机理的体外模型。     

Controlling interrelationships of progesterone/LH and estradiol/LH in mares

The interrelationships of progesterone, estradiol, and LH were studied in mares (n=9), beginning at the first ovulation (Day 0) of an interovulatory interval. An increase in mean progesterone concentrations began on Day 0 and reached maximum on Day 6, with luteolysis beginning on Day 14. A common progesterone threshold concentration of about 2 ng/ml for a negative effect on LH occurred at the beginning and end of the luteal phase. Progesterone and LH concentrations decreased at a similar rate from Day 6 until the onset of luteolysis on Day 14, consistent with a decreasing positive effect of LH on progesterone. Concentrations of LH during the increase in the ovulatory surge consisted of two linear regression segments involving a rate of 0.4 ng/ml/day for Days 14-22 and 1.8 ng/ml/day for Day 22 to 1 day after the second ovulation. The end of the first segment and beginning of the second segment was 2 days before ovulation and was the day the ovulatory estradiol surge was at a peak.     

Temporal relationship of the prolactin-dependent LH-induced LH receptor to the LH stimulus

The time course for LH induction of luteinizing hormone (LH) receptors as reflected in binding of ¹²⁵l-labeled hCG was investigated in hypophysecto-mized adult male rats. A low dose of oLH (10 μg) was administered to hypophysectomized adult male rats following pretreatments with prolactin, follicle-stimulating hormone (FSH), growth hormone (GH), or saline. Testicular binding of hCG was determined at different times following the LH injection using Leydig cell membrane preparations from a testicular homogenate. Seven days after hypophysectomy, hCG binding was at a nadir of 19 ± 7% (mean ± SD) of control values. Pretreatment with prolactin (100 μg/day) for 7 days was associated with a nonsignificantly different hCG binding that was 30 ± 5% of control values. Prolactin pretreatment plus a single 10 μg LH i.p. injection increased ¹²⁵l hCG binding up to 56 ± 10% of control values within 30 minutes of the LH injection. Luteinizing hormone-induced hCG binding persisted at a high level (51 ± 4% of control values) for 2 hours but returned to hypophysectomized control levels 6 hours after the i.p. LH injection. Seven days pretreatment with FSH or GH at 100 μg/day plus 10-μg LH injections was also tested. Neither FSH nor GH had a statistically significant effect on hCG binding nor could they mimic the ability of prolactin to allow for LH induction of hCG binding in the hypophysectomized adult male rats. These studies suggest that the induction or “up-regulation” of Leydig cell hCG binding by ovine LH is rapid and specifically dependent upon pre-exposure to prolactin.     

Neurotensin inhibits LH release

The present studies were designed to assess the effect of neurotensin on the release of LH, FSH, and prolactin in long-term castrated female rats. The animals were implanted in the lateral ventricle of the brain wih a cannula to allow the administration of either neurotensin or the vehicle. The peptide (30 microgram, dissolved in saline) or the control saline solution was injected intraventricularly in a volume of 10 microliter following pentobarbital anesthesia. Blood samples were collected at sacrifice 15, 30 and 60 min after injection. A significant decrease of serum LH levels was already present in neurotensin-treated animals at 15 min, and was maintained up to the end of the experiment. This decrease was not accompanied by any change in FSH or prolactin secretion. The results suggest that this tridecapeptide participates in the control of LH release and provide new data on the separate control of the release of the two gonadotropins.     

大鼠卵巢促黄体激素/人绒毛膜促性腺激素受体cDNA的克隆和在昆虫细胞中的高效表达

促黄体激素/人绒毛膜促性腺激素受体(LH/hCG receptor)是一种与G-蛋白偶联的糖蛋白。本文报道了从大鼠卵巢cDNA库中筛选LH/hCG受体cDNA及其在昆虫细胞中的高效表达。LH/hCG受体cDNA全长2403bp,编码受体信号肽和成熟受体674个氨基酸。用多角体病毒表达载体pVL1393,LH/hCG受体cDNA在昆虫细胞中得到高效表达。在非还原和还原条件下的SDS-PAGE分析显示,用亲和层析分离纯化的受体表观分子量分别为120Kd和92Kd。经配基结合和Scatchard Plot分析表明,其与hCG反应的Kd为8.4×10~(-9)mol/L,与CHO细胞表达产物相似。     

Membrane Curvature Induced by Aggregates of LH2s and Monomeric LH1s

The photosynthetic apparatus of purple bacteria is contained within organelles called chromatophores, which form as extensions of the cytoplasmic membrane. The shape of these chromatophores can be spherical (as in Rhodobacter sphaeroides), lamellar (as in Rhodopseudomonas acidophila and Phaeospirillum molischianum), or tubular (as in certain Rb. sphaeroides mutants). Chromatophore shape is thought to be influenced by the integral membrane proteins Light Harvesting Complexes I and II (LH1 and LH2), which pack tightly together in the chromatophore. It has been suggested that the shape of LH2, together with its close packing in the membrane, induces membrane curvature. The mechanism of LH2-induced curvature is explored via molecular dynamics simulations of multiple LH2 complexes in a membrane patch. LH2s from three species—Rb. sphaeroides, Rps. acidophila, and Phsp. molischianum—were simulated in different packing arrangements. In each case, the LH2s pack together and tilt with respect to neighboring LH2s in a way that produces an overall curvature. This curvature appears to be driven by a combination of LH2's shape and electrostatic forces that are modulated by the presence of well-conserved cytoplasmic charged residues, the removal of which inhibits LH2 curvature. The interaction of LH2s and an LH1 monomer is also explored, and it suggests that curvature is diminished by the presence of LH1 monomers. The implications of our results for chromatophore shape are discussed.     

Effect of progesterone on basal LH and episodic LH and FSH secretion in heifers

Heifers between Days 6 and 10 of the cycle were allocated at random to groups of 8 and treated with (i) a 4% progesterone-releasing intravaginal device (PRID) + oestrogen capsule for 12 days; (ii) 4% PRID for 12 days; (iii) 20% PRID for 12 days; (iv) 4% for 14 days; or (v) 20% PRID for 14 days. Blood was obtained daily during treatment and at 2- or 4-h intervals for 72 h after removal of PRIDs. Some animals were sampled every 20 min for 4.676 h on the 3rd day after PRID insertion, and 1 day before and 36 h after removal of the PRID insertion, and 1 day before and 36 h after removal of the PRID. During progesterone treatment there was: (i) no correlation between concentrations of progesterone and LH within days; (ii) a significant negative correlation between progesterone and days (P less than 0.01) and also between progesterone and LH over days (P less than 0.01); (iii) the overall correlation co-efficient between LH and days was positive (P less than 0.05). The amplitude of LH or FSH episodes was not affected as progesterone concentrations declined during PRID treatment, but the number of LH (but not FSH) episodes was increased (p less than 0.01). After PRID removal, the amplitude of both LH and FSH episodes increased (P less than 0.01). We suggest that progesterone is part of a negative feedback complex on LH secretion in cattle and that this effect is apparently mediated through frequency of episodic LH release.     

Correlation of hypothalamic LHRH, pituitary LH and plasma LH in developing rats.

Hypothalamic LHRH, pituitary LH and plasma LH levels were measured in rats of both sexes from day 5-60 after birth. The content of hypothalamic LHRH was very high in one-week-old male and female rats. It declined gradually till day 17 in the female rat and sharply on day 10 in the male rat. Subsequently the content of hypothalamic LHRH increased and showed peak values on day 25 in the female rat and on day 45 in the male rat. It decreased markedly at respective times of puberty in both sexes (day 37 in the female rat and day 52-60 in the male rat). Results of the study suggest that maturation of hypothalamo-hypophyseal-axis proceeds in three distinct stages. Observations on days 17, 25 and 37 in the female rat and on days 5, 7, 10 and 22 in the male rat clearly show an inverse relationship between hypothalamic LHRH and plasma LH and a parallel relationship between pituitary and plasma LH. Marked decline in the content of hypothalamic LHRH at respective times of puberty in both sexes indicates that the release of threshold levels of LHRH from the hypothalamus may apparently be the event initiating the pubertal changes in rat.     

桉树LH22、U6无性系茎提取液对绿豆插条发根和种子萌发的影响

研究表明,难生根的尾叶桉×赤桉LH22无性系茎的粗提液对绿豆插条发根率、不定根长度有极明显的抑制作用,而易生根的尾叶桉U6无性系茎的粗提液却没有抑制作用.对这些茎粗提液进一步用有机溶剂萃取分离,各萃取相进行白菜种子萌发的生物测验,表明LH22中的水相、乙醚相含有抑制种子萌发的物质,经Duncan's新复极差法分析抑制作用显著,而易生根的U6中却无影响.水相、乙醚相分别再经硅胶柱层析技术分离纯化得到多种不同的成分,进行白菜种子萌发生物测验后,有数种成分有明显的抑制作用.因此说明,难生根的LH22无性系茎内含有成分不同的生根抑制物质,而易生根的U6无性系茎内几乎没有或含有少量这些生根抑制物质.