首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
We have reported that iv administration of conjugated estrogens results in no significant change in the plasma LH-RH level during the negative feedback phase of LH, suggesting that estrogen does not suppress LH by decreasing hypothalamic LH-RH. To determine the site of estrogen action during the negative feedback phase, we studied the pituitary response to a small amount of LH-RH after estrogen administration in normal cyclic women in the mid-follicular phase. The pituitary responses to an iv bolus of 2.5 micrograms of synthetic LH-RH were evaluated by measuring serum LH and FSH 2 h before and 8 h after administration of 20 mg of conjugated estrogens (Premarin). The mean levels of serum LH and FSH were significantly (p less than 0.05) decreased 8 h after the injection. The peak responses of LH and FSH to LH-RH were also significantly (p less than 0.05) reduced after Premarin administration. These findings suggest that the negative feedback effect of estrogen on gonadotropin secretion is caused by its direct suppression on the pituitary response to LH-RH.  相似文献   

2.
Plasma samples were obtained by repeated venopunctures immediately before, and at 15, 30, 60, 120 and 180 min after intravenous bolus administration of 100 micrograms synthetic LH-RH in normal and various anovulatory women. Plasma hLH levels were determined by an in vitro bioassay and a radioimmunoassay with improved reagents. The LH-RH stimulation induced an abrupt elevation of both biological and immunological hLH activities in normal and anovulatory women, although the responsiveness to LH-RH differed from case to case. Both elevated biological and immunological hLH activities decreased gradually with a half disappearance time of 122.4 +/- 27.9 min and 112.5 +/- 25.4 min, respectively (Mean +/- S.D.). A transient and significant depression in the ratio of biological to immunological hLH activities (B/I ratio) was observed at 15 min after the LH-RH administration in normal subjects. This depression is attributable to the cross-contamination of an increased amount of hLH subunits induced by LH-RH stimulation. The B/I ratios were significantly elevated throughout the investigation period in the anovulatory patients when compared with those in the normal subjects. This elevation appears to indicate the increased discharge of special type(s) of hLH subpopulations of high biological potency in the anovulatory cases.  相似文献   

3.
Five normal men received constant intravenous infusions of luteinizing hormone-releasing hormone (LH-RH), 0.2 mug/min, for 14-19 hours. Serum levels ofluteizining hormone (LH) revealed a biphasic pattern of increase, reaching maximal values by 4 hours after the infusions began, then remained near that level until the infusions ceased. Serum follicle stimulating hormone (FSH) levels rose gradually to maximal values by 6-13 hours and maintained this level until the end of the infusions. Testosterone (T) levels revealed gradual increases throughout the infusions. These results confirm an increase in serum T levels with prolonged endogenous gonadotrophin stimulation. This is in contrast to the inability of several previous studies to demonstrate an increase in T levels following the relatively short gonadotrophin elevation produced by single-shot LH-RH administration. The T increases produced, however, were quantitatively much less than those reported during prolonged LH-RH infusions in rams, suggesting that the human testis is less responsive to endogenous gonadotrophin stimulation than is that of the ram. In addition, prolonged LH-RH stimulation did not cause pituitary refractoriness in men as has been described in animals.  相似文献   

4.
目的:探讨醒脑静注射液联合血府逐瘀汤对蛛网膜下腔出血(subarachnoidhemorrhage,SAH)大鼠C反应蛋白(C-reactionprotein, CRP) 、肿瘤坏死因子-a(Tumor necrosis factor-a,TNF-a)的影响。方法:50 只大鼠随机分为5 组:正常组,模型组,醒脑静组 (0.3 mL/kg),血府逐瘀汤组(0.3 mL/kg),联合用药组(醒脑静联合血府逐瘀汤)。除正常组外,其余4组采用" 二次枕大池注血法" 建立大鼠SAH 模型。从造模成功后的第1 d 开始给药,连续给药7 d。正常对照组及模型组给予等量生理盐水。分别在术前、术后 1 d、3 d、7 d、14 d取血浆及脑脊液,按ELISA 试剂盒说明书分别测定各组血清及脑脊液中肿瘤坏死因子-alpha(TNF-alpha)、C- 反应蛋白 (CRP)的含量。结果:(1)术后随着时间推移,SAH大鼠血清及脑脊液中TNF-alpha及CRP 含量逐渐上升,在第7 d 达到高峰。(2)术 后第1 d,与正常组比较,模型组中血清及脑脊液中TNF-琢、CRP含量均显著上升,差异显著(P<0.01);与模型组比较,醒脑静组及 血府逐瘀汤组中血清及脑脊液中TNF-alpha、CRP 含量无差异(P>0.05),而联合用药组中血清及脑脊液中TNF-琢含量下降,差异具有 显著意义(P<0.05)。(3)术后第3 d、7 d、14 d,与正常组比较,模型组中血清及脑脊液中TNF-琢、CRP 含量均显著上升,差异显著 (P<0.01);与模型组比较,醒脑静组、血府逐瘀汤组及联合用药组中血清及脑脊液中TNF-琢、CRP 含量下降,差异均显著(P<0.0 1),与醒脑静组或血府逐瘀汤组比较,联合用药组中血清及脑脊液中TNF-alpha、CRP含量下降,差异均显著(P<0.05)。结论:醒脑静 联合血府逐瘀汤能有效缓解SAH大鼠CVS,与降低SAH大鼠血清及脑脊中TNF-alpha、CRP 水平有关。  相似文献   

5.
The discovery and reliable detection of markers for neurodegenerative diseases have been complicated by the inaccessibility of the diseased tissue- such as the inability to biopsy or test tissue from the central nervous system directly. RNAs originating from hard to access tissues, such as neurons within the brain and spinal cord, have the potential to get to the periphery where they can be detected non-invasively. The formation and extracellular release of microvesicles and RNA binding proteins have been found to carry RNA from cells of the central nervous system to the periphery and protect the RNA from degradation. Extracellular miRNAs detectable in peripheral circulation can provide information about cellular changes associated with human health and disease. In order to associate miRNA signals present in cell-free peripheral biofluids with neurodegenerative disease status of patients with Alzheimer''s and Parkinson''s diseases, we assessed the miRNA content in cerebrospinal fluid and serum from postmortem subjects with full neuropathology evaluations. We profiled the miRNA content from 69 patients with Alzheimer''s disease, 67 with Parkinson''s disease and 78 neurologically normal controls using next generation small RNA sequencing (NGS). We report the average abundance of each detected miRNA in cerebrospinal fluid and in serum and describe 13 novel miRNAs that were identified. We correlated changes in miRNA expression with aspects of disease severity such as Braak stage, dementia status, plaque and tangle densities, and the presence and severity of Lewy body pathology. Many of the differentially expressed miRNAs detected in peripheral cell-free cerebrospinal fluid and serum were previously reported in the literature to be deregulated in brain tissue from patients with neurodegenerative disease. These data indicate that extracellular miRNAs detectable in the cerebrospinal fluid and serum are reflective of cell-based changes in pathology and can be used to assess disease progression and therapeutic efficacy.  相似文献   

6.
目的:探讨中枢神经系统感染患儿血清和脑脊液C反应蛋白(CRP)、降钙素原(PCT)、肿瘤坏死因子-α(TNF-α)及基质金属蛋白酶-9(MMP-9)水平及其临床意义。方法:选择2017年1月~2018年6月期间南京市第二医院收治的中枢神经系统感染患儿93例作为研究对象,其中化脓性脑膜炎62例记为化脓性脑膜炎组,病毒性脑炎31例记为病毒性脑炎组,另选取同期于我院治疗的非中枢神经系统感染患儿40例作为对照组,比较各组血清、脑脊液CRP、PCT、TNF-α、MMP-9水平及阳性率,并计算血清和脑脊液CRP、PCT、TNF-α、MMP-9诊断中枢神经系统感染的灵敏度、特异度及准确度。结果:化脓性脑膜炎组患儿血清、脑脊液CRP、PCT、TNF-α及MMP-9水平及阳性率高于病毒性脑炎组和对照组,病毒性脑炎组患儿血清、脑脊液CRP、TNF-α及MMP-9水平及阳性率高于对照组(P<0.05),病毒性脑炎组与对照组血清、脑脊液PCT水平及阳性率比较无统计学差异(P>0.05)。血清或脑脊液CRP+PCT+TNF-α+MMP-9联合检验对中枢神经系统感染具有一定的诊断价值。结论:中枢神经系统感染患儿血清、脑脊液CRP、TNF-α、PCT及MMP-9水平明显升高,其中化脓性脑膜炎患儿血清、脑脊液PCT水平高于病毒性脑炎患儿,血清或脑脊液CRP、PCT、TNF-α及MMP-9联合检验对儿童中枢神经系统感染的鉴别诊断具有较高的价值。  相似文献   

7.
Jean H. Dussault 《CMAJ》1974,111(11):1195-1197
Serum thyrotropin (TSH) and prolactin levels were measured after intravenous administration of 400 μg of synthetic thyrotropin-releasing hormone (TRH) in 13 normal subjects and six hypothyroid patients before and after three days of administration of dexamethasone 2 mg per day. In the normal subjects dexamethasone suppressed baseline serum levels and secretion of TSH after TRH stimulation. On the other hand, it had no effect on the hypothyroid patients. In the control group dexamethasone also suppressed baseline serum levels but not secretion of prolactin after TRH stimulation. Dexamethasone had no effect on prolactin levels in the hypothyroid group. It is concluded that in normal patients short-term administration of dexamethasone has an inhibitory effect on TSH secretion at the pituitary level. As for prolactin, our results could indicate that TRH is a more potent stimulator of prolactin secretion than of TSH secretion, or that TSH and prolactin pituitary thresholds for TRH are different.  相似文献   

8.
The effects of the intranasal administration of preparations made from the cerebrospinal fluid of male and female opiate users on the open-field rat behavior were studied. Behavioral differences were demonstrated in the effects of preparations from female and male cerebrospinal fluid. The administration of the "male" preparation produced a significant decrease in the locomotor activity and increase in the immobilization time and grooming duration, while the "female" preparation had the opposite effects. These differences may result from different content of endogenous and exogenous opiates and dopamine (and its metabolites) in the cerebrospinal fluid of male and female opiate users.  相似文献   

9.
In anesthetized rats, the choline levels of cerebrospinal fluid and plasma obtained from blood collected from peripheral vessels (carotid artery, cardiac vessels) and from the transverse sinus were determined with a radioenzymatic assay. Cortical release of choline was studied using the "cup technique." The plasma choline level of the peripheral blood (11.5 mumol/L) was lower than that of the sinus blood. The resulting cerebral arterio-venous difference of choline was negative (3.2 mumol/L) and reflected the net release of choline from the whole brain. The plasma choline levels were not different irrespective of whether the rats were anesthetized with ether, urethane, or pentobarbital. However, the choline level of the cerebrospinal fluid, which normally was lower than the plasma choline levels, was increased by urethane anesthesia to a level between the arterial and venous plasma concentrations of the brain. In old rats (24 months), the choline level of the cerebrospinal fluid was significantly lowered, when compared with the results obtained with younger rats (2-4 months). In rats kept on a low-choline diet for 2 weeks, the plasma choline level of the peripheral blood was reduced to 51% of the control. The effect on the choline level of the sinus blood was smaller; the cerebral arterio-venous difference of choline was not reduced (it was even slightly enhanced). Likewise, the choline level of the cerebrospinal fluid and the cortical release of choline were not altered. Intraperitoneal administration of oxotremorine in pentobarbital-anesthetized rats kept on a low-choline diet increased the plasma levels of choline.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Recently, we developed long-acting microcapsules and microgranules of the LH-RH antagonist SB-75. In this study, we compared the inhibitory effects of a single injection of encapsulated and nonencapsulated LH-RH antagonist SB-75 on gonadotropin and testosterone secretion. The resulting serum SB-75 levels were also measured by RIA. Microgranules containing 4% of this antagonist in poly(DL-lactide-co-glycolide) were administered IM at two different doses (30 and 60 mg/rat) to male rats. Other groups of rats were injected SC with equivalent doses of nonencapsulated SB-75 (1.25 and 2.5 mg/rat). The administration of microgranules at a dose of 60 mg/rat produced a significant elevation of serum SB-75 until day 76, and serum testosterone and LH levels were suppressed below the detection limit of the RIA for a period of 70 days. An equivalent dose of nonencapsulated SB-75 acetate (2.5 mg/rat) produced a significant elevation of SB-75 levels for 20 days and decreased testosterone to castration values and LH levels for merely 21 days. In rats treated with 30 mg microgranules of SB-75 or an equivalent dose of SB-75 acetate (1.25 mg/rat), serum testosterone and LH were suppressed to a similar extent, but for only 2 weeks. In another study, the effect of a single SC injection of 1.25 mg/rat of antagonist SB-75 on pituitary LH-RH receptors was determined, 7 and 60 days after administration. SB-75 produced a significant (p < 0.01) downregulation of membrane receptors for LH-RH 7 days after administration.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
The effects of prolonged treatment with the antagonistic analog of LH-RH (N-Ac-D-p-Cl-Phe1,2, D-Trp3,D-Arg6,D-Ala10) LH-RH (ORG 30276) on the hyperprolactinemia induced by haloperidol were investigated in intact or ovariectomized female rats. Treatment with ORG 30276 for 20 days significantly reduced prolactin levels elevated by daily injections of haloperidol in intact as well as in ovariectomized rats. Administration of ORG 30276 also significantly decreased serum LH levels in both types of rats. It is concluded that the LH-RH antagonist ORG 30276 is able to counteract the hyperprolactinemic effect of haloperidol. This effect might be due to a blockade of the action of endogenous LH-RH on the gonadotrophs, which results in a suppressing of the paracrine action of these cells on the lactotroph.  相似文献   

12.
Abstract— The identification of 3-methoxy-4-hydroxyphenylethanol (MOPET) in human cerebrospinal fluid and in rat brain is described. Use was made of the high sensitivity and selectivity provided by gas chromatography-mass spectrometry. Concentrations of MOPET in human cerebrospinal fluid, rat brain and rat urine together with those of some other catecholamine metabolites are given. The effect of intraperitoneal administration of deuterium-labelled MOPET and haloperidol on rat brain and urine MOPET levels was studied. The quantitative importance of MOPET as an end product of central and peripheral dopamine metabolism in man and rat is discussed.  相似文献   

13.
A R Sheth  P G Shah 《Life sciences》1978,22(23):2137-2140
Daily oral administration of bromocriptine (50 μg/kg) to adult male rats, suppressed serum prolactin levels. The pituitary prolactin levels remained unaltered. Serum FSH levels as well as pituitary FSH levels showed no significant change as compared to the controls. Serum LH levels were significantly decreased in spite of the high pituitary LH levels, in bromocriptine treated rats. In the drug treated rats, in vitro sensitivity of the pituitary to the exogenous LH-RH was not altered; whereas hypothalamic LH-RH content was considerably lowered. These observations suggest the possible effect of bromocriptine on the synthesis of LH-RH in the hypothalamus which leads to the accumulation of LH in the pituitary and decline of serum LH.  相似文献   

14.
目的探讨脑脊液乳酸、血清降钙素原及C反应蛋白对小儿细菌性脑膜炎的诊断价值。方法选取我院2016年4月至2017年6月收治的50例细菌性脑膜炎患儿以及50例病毒性脑膜炎患儿进行作为研究对象,比较2类患儿脑脊液乳酸(LA)、血清降钙素原(PCT)及C反应蛋白(CRP)的水平,并分析其诊断价值。结果细菌性脑膜炎组患儿脑脊液LA、血清PCT及CRP水平显著高于病毒性脑膜炎患儿(均P0.05)。血清PCT诊断的灵敏度和特异度最高(96.4%、90.9%,P0.05)。3项指标联合检测的灵敏度(100.0%)和特异度(95.5%)明显高于任一单项指标(均P0.05)。经过Pearson相关性分析,脑脊液LA、血清PCT及CRP与小儿细菌性脑膜炎均呈显著正相关关系(均P0.05)。结论脑脊液乳酸、血清PCT及CRP对小儿细菌性脑膜炎的诊断和治疗效果监测有重要应用价值。  相似文献   

15.
To investigate how various concentrations of serum prolactin (PRL) influence the priming effect of luteinizing hormone releasing hormone (LH-RH) on the pituitary gland, 24 women with various blood PRL concentrations received intravenous injections of 100 micrograms of synthetic LH-RH twice at an interval of 60 minutes and their serum LH and follicle-stimulating hormone (FSH) were measured and analysed. In the follicular phase with a normal PRL concentration (PRL less than 20 ng/ml, n = 6), marked first peaks of the two hormones following the first LH-RH stimulation and enhanced second peaks after the second LH-RH administration were observed, indicating a typical priming effect of LH-RH on gonadotropins, though the second response of FSH was more moderate than that of LH. In hyperprolactinemia, in which the serum PRL concentration was higher than 70 ng/ml (n = 13), the basal concentration of gonadotropins was not significantly changed but the priming effect of LH-RH on LH and FSH was significantly decreased (p less than 0.01). No marked second peaks of LH and FSH were observed, suggesting an inhibitory effect of hyperprolactinemia on the second release of LH and FSH. In contrast, this effect was restored in a group of women whose serum PRL concentration was between 30 and 50 ng/ml (n = 5). Furthermore, enhanced second peaks of both LH and FSH were noted after successful bromocriptine therapy reduced hyperprolactinemia (PRL greater than 70 ng/ml) to less than 25 ng/ml (n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
C W Beattie 《Steroids》1979,34(4):365-380
Daily administration of LH-RH (100 micrograms sc at 0900 and 1500 h) to rats over day 7-12 (D7-12) of pregnancy induced reovulation by D9 and a sustained decrease in uterine:fetal weight and vaginal bleeding by 0600 h on D10 of pregnancy. Serum hormone levels determined at 0600, 1200, and 2000 h over D7-12 of pregnancy revealed that luteinizing hormone (LH) was significantly elevated after each administration of LH-RH, while prolactin (PRL) was not significantly altered in any systematic fashion. An acute decline in serum progesterone at 2000 h on D7-9 following LH-RH administration was not sustained until after 0600 h on D10 when serum 20 alpha-dihydroprogesterone (20 alpha-hydroxy-4-pregnen-3-one, 20 alpha-DHP) in LH-RH treated animals rose significantly above control (2000 h, D10) and remained elevated throughout D11-12. Progesterone and 20 alpha-DHP values were reflected morphologically after D10 as the corpora lutea of LH-RH treated rats underwent luteolysis. A peak in serum estradiol levels in control animals was observed at 0600 h on D9. Serum estradiol-17 beta levels in LH-RH treated animals were similar to control except at 2000 h on D8 and D12 when LH-RH induced a significant increase. These observations suggest that subsequent to implantation in the rat, the temporal sequence of a decrease in progesterone secretion, luteolysis and pregnancy failure in response to LH-RH does not result from an increase in estradiol secretion attendant to reovulation.  相似文献   

17.
The purpose of this study was to assess the biochemical mechanisms underlying spinal cord stimulation (SCS). Seventeen patients with chronic pain were investigated by measuring cerebrospinal fluid concentrations of endogenous opioids and biogenic amines before and during dorsal column stimulation. Basal cerebrospinal fluid beta-endorphin levels were below the normal range. No significant change of norepinephrine, epinephrine, dopamine, beta-endorphin, beta-lipotropin, or adrenocorticotropic hormone levels were found after SCS. A 50% increase of cerebrospinal beta-endorphin and beta-lipotropin levels occurred in 6 out of 16 patients, namely those where SCS gave the major pain relief. These data confirm the derangement of the endogenous opioid system in chronic pain conditions and suggest that the beta-endorphin response to SCS could have clinical value in predicting the success of treatment.  相似文献   

18.
目的:从食欲素(Orexin, ORX)系统挖掘创伤后应激障碍的神经生物学机制。方法:以单次延长刺激(single prolonged stimulation,SPS)法复制创伤后应激障碍(post traumatic stress disorder,PTSD)大鼠模型,以行为学结合血清中皮质酮和神经元特异性烯醇化酶进行模型评价,通过酶联免疫吸附试验(Elisa)分析大鼠血清与脑脊液中OREXIN水平,以实时荧光定量聚合酶链反应(RT-PCR)检测海马与前额叶皮质中的Orexin受体基因表达。结果:实验成功的复制了PTSD模型,与对照组相比,模型组大鼠血清中皮质酮和神经元特异性烯醇化酶的含量均极显著升高(P0.01),脑脊液中Orexin A、Orexin B的含量均显著升高(P0.01),海马和皮质中ORX1R与ORX2R均极显著下降(P0.01)。结论:PTSD大鼠的应激损伤与Orexin及其受体表达水平的变化密切相关。  相似文献   

19.
Site of feedback control of FSH secretion in the male rat was studied by measuring changes in serum LH, FSH and hypothalamic LH-RH by radioimmunoassay in rats after castration and after 500 rad X-irradiation to the testis. The rise in serum LH and FSH in castrated animals was associated with a significant fall in hypothalamic LH-RH 16 and 24 days after castration. Serum FSH rose significantly after X-irradiation without a significant change in serum LH or hypothalamic LH-RH content up to 30 days after irradiation. When pituitary halves from X-irradiated animals were incubated in vitro in the presence or absence of synthetic LH-RH, there was a significant rise in FSH (but not LH) released in the incubation medium in the absence of added LH-RH. The response of the pituitaries to LH-RH was, however, not different between control and irradiated rats. It is concluded that the testicular FSH-inhibitory substance acts predominantly at the pituitary gland on the LH-RH independent release of FSH.  相似文献   

20.
The effects of central nervous system administration of morphine on secretion of luteinizing hormone (LH), follicle-stimulating hormone, and prolactin were investigated in ovariectomized gilts stereotaxically implanted with lateral ventricular cannulas. In Experiment 1, mean serum LH and follicle-stimulating hormone concentrations and serum LH pulse frequency were unaffected by artificial cerebrospinal fluid administration (P greater than 0.1), but decreased (P less than 0.01) in 8 of 11 gilts when 500 micrograms of morphine were given 3 hr later. Serum LH pulse amplitude was unaffected (P greater than 0.1) by cerebrospinal fluid or morphine injection. In Experiment 2, luteinizing hormone concentrations decreased (P less than 0.0001) and prolactin concentrations increased (P less than 0.0001), but follicle-stimulating hormone concentrations did not change (P greater than 0.1) after 500 micrograms of morphine. Gonadotropin responses to 10 micrograms of gonadotropin-releasing hormone, given 2 hr after intraventricular injection, were similar (P greater than 0.1) for morphine- and cerebrospinal fluid-treated gilts. These results indicate that morphine inhibits LH secretion at the level of the central nervous system, and are consistent with the concept that endogenous opioid peptides participate in the regulation of gonadotropin and prolactin release in pigs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号