Increased litter size in the rat x-irradiated during the estrous cycle before mating

Average numbers of ovulations, implantations, and living fetuses obtained from rats x-irradiated during the estrous cycle before mating are a function of both the radiation dose and the time of exposure during the cycle. Animals irradiated during metestrus or the day thereafter exhibit significant increases in the factors studied, while those irradiated on the 3rd day after metestrus maintain fewer implantations after exposure to 300, 500, and 600 roentgens, and fewer living fetuses after exposure to 100 to 600 roentgens.     

Regulation of carcinogen metabolism in the rat ovary by the estrous cycle and gonadotropin

The activity of 7,12-dimethylbenz[a]anthracene hydroxylase in the rat ovary is several times higher in the proestrous phase of the estrous cycle than in the estrous and metestrous plus diestrous phases. Administration of gonadotropin leads to a similar increase in the capacity of the ovary to metabolize xenobiotics. This variation in the activity of 7,12-dimethylbenz[a]anthracene hydroxylase during the estrous cycle may be related to the marked changes in the incidence of ovarian cancer during menopause and in women taking contraceptive pills.     

5-HT与NSE和SYN在牛周期黄体细胞中的共存

【目的】探讨弥散性神经内分泌细胞标记物在牛黄体细胞中的共存现象,以期为黄体细胞的内分泌研究提供理论依据。【方法】采集黄牛黄体,常规方法制备石蜡切片,采用免疫组织化学链霉素抗生物素蛋白-过氧化物酶法,结合免疫组化双标记法染色后,镜检拍照,研究牛周期性黄体细胞中5-HT与NSE和SYN的共存情况。【结果】黄体组织中含有这3种标记物的单标记和5-HT与其他两者的双标记免疫反应阳性细胞,其主要以散在形式分布于黄体中,细胞形态多呈圆形、椭圆形和梭形,阳性细胞平均数由多至少依次为:5-HT、NSE、SYN/5-HT、SYN和NSE/5-HT;在黄体细胞以外的卵巢细胞中未观察到这3种物质的存在。【结论】牛黄体组织中存在5-HT、NSE、SYN 3种标记物和SYN/5-HT、NSE/5-HT双标记免疫反应阳性细胞,提示黄体组织在发生的同时也存在着部分细胞的神经内分泌分化。     

奶山羊周期黄体中催产素的免疫组化定位

运用免疫组化 ABC法对奶山羊周期黄体中催产素 (OT)的定位进行了研究。结果表明 ,奶山羊周期黄体中存在数量较多的 OT免疫反应阳性细胞。OT阳性细胞根据胞质内反应颗粒着色的深浅可分为强阳性、中等阳性和弱阳性细胞 3种。阳性细胞在形态上以圆形、卵圆形为主 ,另有相当数量的细胞具有突起 ,小梁两侧及黄体中央近腔区域的阳性细胞则多呈现为长梭形。从分布上看 ,强阳性细胞主要分布于黄体周边 ,少数散布于中央区域 ,中等阳性及弱阳性细胞则均匀分布于整个黄体组织中。连续切片 HE染色的对照观察显示 ,奶山羊周期黄体中的 OT主要是由大黄体细胞分泌 ,小黄体细胞也可产生少量的 OT。     

GPR30在小鼠发情周期卵巢中的分布和表达

为了获得G蛋白偶联受体30(GPR30)在小鼠发情周期卵巢中的分布和表达规律,分别运用免疫组织化学SP法和RT-PCR法,对小鼠发情前期、发情期、发情后期和间情期卵巢中GPR30分布及GPR30 mRNA的表达进行研究.结果显示:GPR30免疫反应阳性产物分布于小鼠卵巢各级卵泡的颗粒细胞、卵泡膜细胞、卵母细胞以及黄体细胞和间质细胞的细胞膜和胞浆中,以次级卵泡和成熟卵泡的颗粒细胞中分布最多、着色最深;GPR30的相对表达量在小鼠发情周期卵巢中以间情期最低且极显著低于其他3个时期(P＜0.01),发情期最高但与发情前期和发情后期无显著差异(P＞ 0.05).发情周期卵巢中GPR30 mRNA的表达变化规律与GPR30的表达基本一致,其中发情期最高且极显著高于其他时期(P＜0.01),间情期最低且极显著低于其他时期(P＜0.01). GPR30在小鼠卵巢中的分布和表达量变化与卵泡发育过程以及发情周期雌激素变化规律基本一致,提示其介导了雌激素对发情周期卵泡发育和卵母细胞成熟的调节.     

KiSS-1/GPR54系统在不同发情周期母羊下丘脑中的表达规律

【目的】研究发情周期各阶段KiSS-1/GPR54系统在母羊下丘脑中的表达规律。【方法】将12只雌性小尾寒羊随机分为4组,每组3只,分别于发情前期、发情期、发情后期和间情期,颈动脉放血致死后采集其下丘脑,采用实时荧光定量PCR技术研究母羊发情周期不同阶段下丘脑中KiSS-1和GPR54基因的表达规律。【结果】母羊发情周期各阶段下丘脑上均有KiSS-1和GPR54基因表达;发情期母羊下丘脑KiSS-1基因的表达量极显著高于发情后期、间情期和发情前期(P<0.01),而发情后期、间情期和发情前期之间差异不显著;发情周期的不同阶段,GPR54基因在母羊下丘脑中的表达量无显著差异(P>0.05)。【结论】发情期母羊下丘脑KiSS-1基因的表达量极显著高于发情周期其他阶段(P<0.01),GPR54基因在母羊发情周期各阶段的表达量无显著差异。     

Dynamic complex formation during the yeast cell cycle

To analyze the dynamics of protein complexes during the yeast cell cycle, we integrated data on protein interactions and gene expression. The resulting time-dependent interaction network places both periodically and constitutively expressed proteins in a temporal cell cycle context, thereby revealing previously unknown components and modules. We discovered that most complexes consist of both periodically and constitutively expressed subunits, which suggests that the former control complex activity by a mechanism of just-in-time assembly. Consistent with this, we show that additional regulation through targeted degradation and phosphorylation by Cdc28p (Cdk1) specifically affects the periodically expressed proteins.     

小梅山猪发情周期生殖激素变化的研究

以ESR基因BB型小梅山母猪、大白母猪为研究对象,测定发情周期血清生殖激素(雌二醇、雌三醇、孕酮、促卵泡素和促黄体素)浓度,探讨小梅山猪高产的内分泌机制。结果表明:小梅山猪雌二醇、孕酮浓度均显著(P<0.05)高于大白猪,大白猪雌三醇和促黄体素浓度显著(P<0.05)高于小梅山猪,而两品种猪促卵泡素则无显著差异。初步认为在诸多生殖激素动态相互作用中,雌激素和孕酮是决定小梅山母猪(ESR基因BB型)繁殖力的主效激素。     

波尔山羊发情周期和妊娠期外周血浆中孕酮、雌二醇和睾酮的浓度变化

测定了波尔山羊在发情周期 ( 4头 )和妊娠期 ( 5头 )外周血浆中孕酮、雌二醇和睾酮的浓度变化 ,结果显示 :发情开始孕酮浓度很低 [( 1.5± 0 .2 3)ng/ml],第 7d开始明显升高 [( 3.5± 0 .2 3)ng/ml],第 11d达最高[( 8.3± 0 .2 3)ng/ml],以后逐渐下降 ;雌二醇含量在发情当天最高 [( 6 4 .4± 9.6 )pg/ml],然后下降 ,但有波动 ;睾酮浓度在发情时较低 [( 15 .0± 2 .1)pg/ml],第 11d达最高 [( 30 .2± 5 .3)pg/ml]。在妊娠期的最初 15d ,3种激素的变化与发情周期相类似 ,但第 2 0d后孕酮明显升高 [( 12 .7± 3.3)ng/ml],以后至分娩前维持在较高水平 ;雌二醇从 2 0d起开始上升 ,分娩前 7d达最高 [( 15 3.7± 16 .7)pg/ml],分娩后下降到较低水平 ;妊娠后 10d血浆睾酮浓度较低 ,维持在 2 0～ 5 0pg/ml内波动 ,分娩前 7d上升至最高 [( 75 .3± 13.3)pg/ml],分娩后下降至较低水平     

G15对发情周期小鼠卵巢表皮生长因子受体表达的影响

【目的】研究G蛋白偶联雌激素受体(G-protein-coupled estrogen receptor,GPER)对发情周期小鼠卵巢表皮生长因子受体(Epidermal growth factor receptor,EGFR)表达的影响。【方法】间情期小鼠腹腔注射GPER抑制剂G15,按注射剂量0.3,1.5和7.5nmol/只设3个注射组,另设腹腔注射等体积生理盐水的对照组;药物注射后,依次取发情前期、发情期、发情后期和间情期小鼠的卵巢,用免疫组织化学SP法和RT-PCR法分别检测各组小鼠发情周期不同阶段卵巢EGFR及其mRNA的表达。【结果】EGFR免疫组化阳性产物主要分布于卵巢的各级卵泡中,阳性染色随卵泡发育而逐渐增强,其中颗粒细胞越靠近卵母细胞染色越强,发情周期卵巢EGFR相对表达量表现为发情期发情前期间情期发情后期。小鼠注射G15后,各情期卵巢中EGFR的表达呈G15剂量依赖性减弱,除发情后期外,均极显著下降(P0.01);1.5和7.5nmol/只G15注射组各情期EGFR的相对表达量无显著差异(P0.05),但均极显著低于0.3nmol/只G15注射组(P0.01)。EGFR mRNA的变化规律与EGFR相对表达量的变化趋势完全一致。【结论】G15可在一定程度上通过GPER下调发情周期小鼠卵巢中EGFR的表达,从而影响发情周期卵巢的功能。     

Partitioning of the matrix fraction of the Golgi apparatus during mitosis in animal cells

The Golgi apparatus is partitioned during mitosis in animal cells by a process of fragmentation, dispersal, and reassembly in each daughter cell. We fractionated the Golgi apparatus in vivo using the drug brefeldin A or a dominant-negative mutant of the Sar1p protein. After these treatments, Golgi enzymes moved back to the endoplasmic reticulum, leaving behind a matrix of Golgi structural proteins. Under these conditions, cells still entered and exited mitosis normally, and their Golgi matrix partitioned in a manner very similar to that of the complete organelle. Thus, the matrix may be the partitioning unit of the Golgi apparatus and may carry the Golgi enzyme-containing membranes into the daughter cells.     

GHS-R1a在大鼠下丘脑-垂体-卵巢轴上的定位及其mRNA的周期性表达

取成年SD大鼠的下丘脑、垂体、卵巢组织制成石蜡切片,采用PV-9000两步法免疫组织化学检测GHS-R1a在下丘脑-垂体-卵巢轴上的定位.实时荧光定量PCR检测GHS-Rla mRNA在不同发情周期大鼠F丘脑-垂体-卵巢轴上的表达.结果表明:GHS-R1a主要分布在下丘脑的弓状核、腹内侧核、正中隆起等,腺垂体的嗜色细胞...     

GPER激动剂对发情周期小鼠卵巢EGFR表达的影响

【目的】探讨G蛋白耦联雌激素受体(G-protein-coupled estrogen receptor,GPER)激动剂对卵巢表皮生长因子受体(Epidermal growth factor receptor,EGFR)表达的影响,为阐明GPER和EGFR在卵巢功能维持中的作用奠定基础。【方法】取间情期小鼠,将其分为40,200,1 000ng/只G-1腹腔注射组和对照组(腹腔注射等体积生理盐水),每组20只,各组小鼠进行相应的处理。注射G-1后,依次取发情前期、发情期、发情后期和间情期小鼠各5只,脱颈处死,迅速取出卵巢,采用免疫组织化学SP法和实时定量RT-PCR法,研究不同剂量GPER激动剂G-1对发情周期小鼠卵巢EGFR分布及其mRNA表达的影响。【结果】EGFR在小鼠卵巢的各级卵泡、黄体和间质中均有表达,且在卵泡颗粒细胞和卵母细胞中表达最明显,在黄体和间质中的表达较微弱。同一发情时期卵巢中,EGFR的相对表达量随注射G-1剂量的增加而升高,除发情后期外,其他3个时期以1 000ng/只G-1注射组均极显著高于对照组(P0.01);间情期和发情前期则以200ng/只G-1注射组显著高于对照组(P0.05)。各组发情周期小鼠卵巢中EGFR mRNA表达量的变化规律与EGFR相对表达量的表现基本一致。【结论】G-1对发情周期卵巢中EGFR的表达有一定的上调作用,提示GPER可介导雌激素经EGFR信号级联参与卵巢周期性生殖活动和卵泡生长发育的调节。     

Dynamic changes in inhibin messenger RNAs in rat ovarian follicles during the reproductive cycle

The alterations in morphology and function of the ovarian follicle as it matures, ovulates, and becomes a corpus luteum are dramatic. A variety of steroid and polypeptide hormones influence these processes, and the ovary in turn produces specific hormonal signals for endocrine regulation. One such signal is inhibin, a heterodimeric protein that suppresses the secretion of follicle-stimulating hormone from pituitary gonadotrophs. Rat inhibin complementary DNA probes have been used to examine the levels and distribution of inhibin alpha-and beta A-subunit messenger RNAs in the ovaries of cycling animals. Striking, dynamic changes have been found in inhibin messenger RNA accumulation during the developmental maturation of the ovarian follicle.     

Localization of the G protein betagamma complex in living cells during chemotaxis

Gradients of chemoattractants elicit signaling events at the leading edge of a cell even though chemoattractant receptors are uniformly distributed on the cell surface. In highly polarized Dictyostelium discoideum amoebas, membrane-associated betagamma subunits of heterotrimeric guanine nucleotide-binding proteins (G proteins) were localized in a shallow anterior-posterior gradient. A uniformly applied chemoattractant generated binding sites for pleckstrin homology (PH) domains on the inner surface of the membrane in a pattern similar to that of the Gbetagamma subunits. Loss of cell polarity resulted in uniform distribution of both the Gbetagamma subunits and the sensitivity of PH domain recruitment. These observations indicate that Gbetagamma subunits are not sufficiently localized to restrict signaling events to the leading edge but that their distribution may determine the relative chemotactic sensitivity of polarized cells.     

Behavioral measurement of neural poststimulation excitability cycle: pain cells in the brain of the rat

A new technique in which elicited behavior of the freely moving rat is used to measure the poststimulation excitability cycle of the central neurons mediating that behavior has been adapted from accepted methods of neurophysiology. A continuous train of pairs of brief pulses was delivered to pain systems in the midbrain. Rate of lever pressing to achieve 3-second rests from this stimulation was measured as a function of the interval separating the pulses within pairs. Evidence for latent addition, absolute refractory period, temporal summation, and adaptation was demonstrated. Obtained relationships suggested that three sets of fibers may carry the aversive signal and that synaptic integration of pain in the brain may be related to Stevens' power law functions.     

Estradiol: specific binding by pituitary nuclear fraction in vitro

The nuclear fraction of a homogenate of anterior pituitary has a marked binding affinity for estradiol but not for other hormonal steroids. Characteristics of the uptake of estradiol by pituitary nuclear fraction are like those reported for the uterus. Study in vitro will be useful in elucidating how direct estrogen feedback control of anterior pituitary function is mediated.     

Hydroxyurea: differential lethal effects on cultured mammalian cells during the cell cycle

Hydroxyurea has a differential lethal effect on cultured Chinesehamster cells that are at different stages in their cell cycle. Cells synthesizing DNA at the time of exposure to the drug are lethally damaged. Cells in the phase of growth preceding DNA synthesis (G(1)) survive but are prevented from beginning DNA synthesis. Cells in the phase after DNA synthesis (G(2)) survive and appear to progress until just before the beginning of the next period of DNA synthesis. This differential lethal and inhibitory effect of hydroxyurea may be useful for synchronizing asynchronous cell populations and explaining effects of the drug in human therapy.     

Cysteamine: differential x-ray protective effect on Chinese hamster cells during the cell cycle

Cysteamine present during x-irradiation protects synchronized Chinese hamster cells in culture against lethal damage at all stages of the cell cycle. The effect is greatest for cells irradiated at sensitive stages such as G(1) and least for resistant cells; for example, late S (dose-modifying factors 4.2 and 2.7, respectively). The effect of 50 millimolar cysteamine is to render almost invariant the normally variant x-ray age response for lethality. This suggests that there are two components of x-ray damage, only one of which is age dependent, and it is against this component that cysteamine protects the cell. Cystamine, however, has no protective effect upon these cells at any stage of the cell cycle.