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.
In an attempt to find a preferential inhibitor of serum FSH, a number of C18, C19 and C21 steroids were evaluated for suppressive effects on LH and FSH and stimulatory effects upon ventral prostate weight in the acutely castrate adult male rat. C21 steroids had no effect. The C19 steroids were listed in order of potency with regard to suppressing LH, FSH and stimulating ventral prostate weight. All C19 steroids that had an inhibitory effect on gonadotropins also stimulated ventral prostate weight and all demonstrated preferential inhibition of LH over FSH. Two C18 steroids were tested, estradiol-17β and estrone; estradiol-17β suppressed LH and FSH in a parallel fashion. Four prostaglandins were evaluated with regard to effect on gonadotropins and ventral prostate weight; none demonstrated effect.  相似文献   

2.
Serum LH and FSH levels were determined before and after LH-RH injection (100 micrograms, i.m.) in patients with prostatic cancer who were chronically treated with either chlormadinone acetate (CMA, 100 mg/day) or ethynylestradiol (EE, 1 mg/day). In patients treated with EE, the levels of serum LH and FSH before and after injection of LH-RH were significantly lower than those in controls. On the other hand in patients treated with CMA, the basal levels of serum gonadotropins did not differ from those in controls, and the increase in gonadotropin after LH-RH injection was comparable to that in controls. To examine the effects of these steroids on the hypothalamo-hypophysial axis in the regulation of gonadotropin secretion, CMA or EE was implanted in castrated male rats. CMA, EE or cholesterol (control) was implanted in the hypothalamic median eminence-arcuate nucleus region through a stainless doublecannula. EE implantation resulted in a 75% decrease in serum LH (p < 0.001) and a 38% decrease in serum FSH (p < 0.05) from the control levels on day 5 of implantation. On the other hand, CMA implantation induced a 33% decrease in serum LH (p < 0.05) from the control level on day 3 of implantation, but no significant change in serum FSH levels. The injection of 2 micrograms/kg of LH-RH on day 7 of implantation induced significant lowering of LH and FSH levels. There was no significant difference between serum levels of the hormones 20 min after LH-RH injection for these two groups and those for the control group. These studies suggest that EE has a potent negative feedback effect on both LH and FSH secretion, and that CMA has a mild negative feedback effect on LH secretion.  相似文献   

3.
The purpose of this study was to determine and compare the follicular phase steroid hormone secretion into the utero-ovarian vein by the ovary with a dominant follicle and the contralateral ovary in the same baboon. Serial utero-ovarian vein blood from both sides was collected in 25 baboons by the use of a laparoscope on alternate days, starting on day 1 or 3 of the cycle and continuing through 2 to 3 days post-ovulation. Approximately 3–4 days before the day of expected ovulation, samples were collected at 8-hr intervals. Steroids estradiol (E2) and progesterone (P) were measured in all utero-ovarian vein plasma by radioimmunoassay. In the peripheral plasma, E2, P, LH, and FSH measurements were carried out. Concentrations of steroids were significantly higher on the side of the ovulating ovary by day 5 before ovulation. Individual plots however, indicated that some baboons may establish the dominant side as early as day 11 before ovulation. The preovulatory gonadotropins had a differential effect on the two ovaries. For example, E2 values on the ovulatory side ovary declined after increases in LH/FSH, whereas on the contralateral side these values had increased. Both sides showed increases in the level of P with the increases in LH. The mean interval from E2 peak to LH peak was 24 hrs and LH peak to ovulation was 24 hrs.  相似文献   

4.
Estrogen deficiency as the sole factor underlying post‐menopausal osteoporosis was challenged, in light of reports that both follicular stimulation hormone (FSH) receptor and FSHβ knockout mice were resistant to bone loss, suggesting a detrimental role for FSH. We assessed whether lowering FSH levels by gonadotropin realizing (GnRH) analog decapeptyl in ovariectomized female rats (OVX) affects bone. Wistar‐derived 25 days old OVX female rats were injected for 10 weeks with estradiol‐17β (E2), with GnRH analog (decapeptyl) or with both. FSH and luteinizing hormone (LH) serum levels were markedly increased in OVX rats, with smaller growth plates with disrupted architecture; heavy infiltration of bone marrow with numerous adipocytes and reduced thickness of cortical bone. In OVX rats treated with E2, FSH, and LH levels were intermediate, the tibia was similar to that of intact rats, but there was reduced thickness of cortical bone. In decapeptyl treated OVX rats, FSH and LH levels were suppressed, the organization of growth plate and the trabecular bone were disrupted, and there were fewer proliferative and chondroblastic cells and a large adipocytes population in bone marrow, but an increased trabecular bone volume (TBV). In the E2 + decapeptyl treatment, FSH and LH levels were suppressed, with partially restored growth plate architecture and improved TBV. In conclusion, E2 deficiency is the dominant factor impairing bone loss in OVX and concomitant changes in FSH/LH levels achieved by decapeptyl have some modulating, though complex role in this setting. The role of high FSH levels in post‐menopausal bone loss requires further investigation using combined sub‐optimal doses of the different hormones. J. Cell. Biochem. 112: 128–137, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   

5.
Orchidectomy was performed on 26-day-old rats via a single midscrotal incision following which 1 of 6 steroids was administered subcutaneously twice daily for 7 days. Each hormone treatment set had its own controls both castrate and intact. Levels of serum LH and FSH were measured by radioimmunoassay. It was found that LH was suppressed to intact levels by testosterone or its active metabolites at doses within the "physiologic dosage range" (equivalent in biological activity to endogenously secreted androgens). FSH suppression with androgens occurred at considerably higher doses; only testosterone could maintain FSH at intact levels with a physiologic dosage. Both 5alpha-dihydrotestosterone, and 3alpha-androstanediol suppressed LH well and FSH partially; 3beta-androstanediol and fluoxymesterone were ineffective over the same dosage range. Estradiol suppressed both LH and FSH. It was concluded that LH is more easily suppressed than FSH by androgens, that there is poor correlation between biologic potency and their gonadotropin-suppression ability, and that testosterone is almost certainly not the final active intracellular androgenic hormone. It was suggested that while a small amount of testicular androgen can maintain the low levels of LH, complete control of FSH secretion may require conversion of testosterone to estrogens.  相似文献   

6.
The following study was conducted to examine the effects of estrogen and polypeptides, given either alone or in combination, on pulsatile gonadotropin secretion. One week after ovariectomy, rats received s.c. injections of oil or various doses (0.5, 5, 20 micrograms) of estradiol benzoate (EB) followed 1 day later by i.v. administration of 60 micrograms purified porcine follistatin, 10 micrograms recombinant inhibin, or the appropriate vehicle. Four hours after injection of the nonsteroids, blood was collected at 10-min intervals for 2 h, and the effects on pulsatile hormone release were assessed. Administration of EB alone dose-dependently suppressed mean and trough (lowest point between two pulses) FSH levels and all parameters of pulsatile LH release. Both follistatin and inhibin at the doses employed suppressed mean FSH levels to an equivalent extent (40%). Follistatin, but not inhibin, suppressed FSH pulse amplitude, while neither polypeptide alone influenced FSH pulse frequency or any parameter of pulsatile LH release. The effects of follistatin and EB on mean FSH levels were additive at all EB doses, whereas the effects of inhibin and EB were additive only at the middle EB dose. Follistatin in combination with the lowest EB dose significantly suppressed mean LH levels. These studies are the first to demonstrate that combined treatment with estrogen and the nonsteroids follistatin and inhibin is more efficacious in suppressing FSH release than treatment with either agent alone, thereby indicating that both steroids and nonsteroids are probably important in the physiological regulation of FSH secretion in rats. The additive effects of these compounds on FSH secretion could form the basis for exploring novel contraceptive interventions.  相似文献   

7.
The present study was undertaken to examine effects of various combinations of epidermal growth factor (EGF), transforming growth factor-b?1 (TGF-b?1), follicle-stimulating hormone (FSH), luteinizing hormone (LH), androstenedione (A4), and estradiol-17b? (E2) on meiotic maturation and cumulus expansion in the pig using an in vitro model system. Oocyte-cumulus cell complexes (OCC) were cultured in the media containing the abovementioned agents for 24 hr and were observed for germinal vesicle breakdown (GVBD), indicative of initiation of meiotic maturation, and for expansion of their cumulus cells. Treatment with EGF significantly increased (P < 0.05) incidence of GVBD, with maximal stimulation occurring at 1 ng/ml (55% vs. 12% in the control). Concentrations of EGF as low as 100 pg/ml significantly stimulated GVBD over control (37% vs. 12%). Addition of EGF (1 ng/ml) and FSH (1.5 μg/ml) together and LH (2 μg/ml) and FSH (1.5 μg/ml) together resulted in significantly higher (P < 0.01) GVBD levels than were observed in response to EGF, FSH, or LH alone. Addition of E2 (1 μg/ml) had no effect by itself but significantly decreased the incidence of GVBD in the presence of FSH and of LH + FSH. Addition of A4 (1 μg/ml) significantly reduced the percentage of oocytes undergoing GVBD when added alone or with FSH. Although both EGF and LH stimulated cumulus expansion, FSH was more effective in stimulating cumulus expansion than EGF or LH. TGF-b?1 had no effect on GVBD or cumulus expansion. These studies indicate that these hormones may have differing roles in oocyte maturation and that their interactions may be part of an intricate system regulating the maturation of oocytes during follicular development in vivo. © 1993 Wiley-Liss, Inc.  相似文献   

8.
The dependence of the acute increases in plasma gonadotropins following castration on luteinizing hormone-releasing hormone (LHRH) was assessed with the use of a potent LHRH antagonist [ALHRH; (Nac-L-Ala1,p-Cl-D-Phe2,D-Trp3,6) LHRH]. Blood samples were collected from male and female rats at the time of castration and 2, 4, 8, 12, 24 and 48 h following and plasma gonadotropin levels were determined. Immediately following castration (diestrus I for females) animals received one of the following treatments: females-vehicle, 100 micrograms ALHRH, 50 micrograms estrogen benzoate (EB), or 100 micrograms ALHRH + 50 micrograms EB; males-vehicle, 100 micrograms ALHRH, 500 micrograms testosterone propionate (TP), or 100 micrograms ALHRH + 500 micrograms TP. ALHRH blocked the selective increase in plasma follicle-stimulating hormone (FSH) observed in female rats as well as the parallel increases in both gonadotropins seen in male rats following castration. Administration of EB or ALHRH + EB to females significantly suppressed both gonadotropins compared with control levels. However, EB alone did not completely block the rise in plasma FSH in females. In males, all three treatments significantly suppressed the increases in both gonadotropins when compared with control levels. These data demonstrate that hypothalamic LHRH plays an essential role in the acute elevations of plasma gonadotropins following castration in rats. In addition, these data suggest that the selective rise of FSH in females is dependent on LHRH stimulation of pituitary gonadotropes.  相似文献   

9.
The pubertal increase in gonadotropins in the female rabbit was inhibited 14-42-fold with Silastic implants of progesterone (P4) testosterone propionate (TP), estradiol benzoate (EB) or P4/EB placed subcutaneously on Day 24 of life. Rabbits with empty implants showed the normal prepubertal increase in circulating gonadotropins. By contrast, rabbits with implants of P4 only, had a 2-fold decrease in LH secretion when peak areas were compared. However, FSH secretion though slightly depressed was not significantly different from controls. The prepubertal increase in circulating gonadotropins was completely suppressed by implants of EB, TP and combined P4/EB. At 115-days-of-age, sexual receptivity and mating were absent in EB-treated animals and significantly suppressed in P4-treated ones when compared to controls, all of which mated. Mating was not completely inhibited in TP and combined P4/EB animals. Corpora lutea were found in all rabbits that mated. In the sexually non-receptive does, vaginal stimulation induced an LH surge in 2 of 15 animals. Ovarian weights and follicular development were significantly suppressed in rabbits with EB implants. Ovarian estradiol content was significantly increased in P4- and TP-treated rabbits. Maximum specific binding for [3H]naloxone was suppressed in the hypothalami of P4-treated rabbits. These results suggest that the prepubertal increase in circulating gonadotropins may have an essential role in the control of sexual maturation in the female rabbit.  相似文献   

10.
Immature rat ovaries increase their secretion of estradiol (E2) when stimulated by gonadotropins but only after a lag period of several hours. Once established, estrogen secretion can be maintained, or increased, by the continued presence of gonadotropin. A combination of ovine FSH+LH given at 2 hr intervals stimulated the estrogen synthesizing system (ESS) of the ovary and serum E2 showed a pronounced rise between 16 and 20 hrs after the initial injection. When given every 2 hrs for 5 doses (0–8 hrs) serum E2 was undetectable. However, it was increased if 20 IU PMS was injected at the time of the last dose of FSH+ LH. Endogenous FSH&LH, increased by hourly injections of LH-releasing hormone for a period of 8 hrs, stimulated the ESS; serum E2 increased at the expected time when this treatment was followed by an injection of PMS.Anti-PMS antiserum given 12 hrs after PMS, prevented the expected rise in serum E2 at 24 hrs. However, FSH, LH or a combination of the two given every 2 hrs beginning at the time of the anti-PMS produced an increase in E2 secretion; the combination was more effective than either hormone alone.These results are consistent with the interpretation that a combined FSH-LH action is responsible for induction of the ESS in the immature rat ovary. The combination of hormones is also very effective in maintaining estrogen secretion but some function appears possible with FSH or LH alone.  相似文献   

11.
C Dupon  A Hosseinian  M H Kim 《Steroids》1973,22(1):47-61
A method is described for the purification and quantitation of estradiol-17β (E2), estrone (E1), testosterone (T), androstenedione (A) and progesterone (P) from a single plasma sample extraction. A combination of Sephadex LH-20 column chromatography and thin layer chromatography is used to separate the phenolic and neutral steroids; quantitation of the purified steroids is by radioimmunoassay (E2, E1) and competitive protein binding (T,A,P) techniques. The precision and accuracy of this method is comparable with that reported by others. A preliminary investigation of the temporal relationship between estrogens androgens, progesterone and serum LH during five normal and one short luteal phase menstrual cycle is presented.  相似文献   

12.
To evaluate whether the median eminence (ME) is the site of action of CRF (corticotropin releasing factor) in inhibiting LH levels in female rats, we have injected CRF (1 nmol) directly into the ME and then measured plasma LH and FSH concentrations in conscious ovariectomized (OVX) rats in the absence or presence of a single dose of estradiol benzoate (EB). CRF caused a significant decrease in plasma LH levels in both OVX and OVX + EB rats at 30 min postinjection, in comparison to the values obtained in animals injected with water only. Injection into the ME of water had no effect on plasma LH levels in either OVX or OVX + EB animals. The results suggest that CRF probably inhibits LH secretion, at least in part by a central action on GnRH release in ME.  相似文献   

13.
Abstract

Dynamic relations between the circulating estrogen and the hypophyseal gonadotropin secretion in the estrous cycle were investigated by replacing the ovaries by an infusion pump in freely moving rats. Female rats were ovariectomized in the morning at certain stages of the 4‐day estrous cycle, and simultaneously infused with estradiol (E2) at a constant rate of 0.35 ng/min up to 120 h through a cannula chronically inserted into the jugular vein. They were killed at 6 h‐intervals. Rats ovariectomized at the second day of diestrus and at estrus showed a sharp rise in LH 36 h and 84 h, respectively, after the initiation of E2 infusion, when the proestrous surge would occur in normal rats. During the other periods, blood levels of LH were very low, exhibiting a small daily rise in the evening. Similarly ovariectomized rats infused with vehicle only showed a gradual rise of gonadotropin secretion, never reaching the surge level. Rats ovariectomized at proestrus and infused with E2 showed a LH surge 12 h later as expected. However, surge‐like LH secretions followed every evening thereafter. Thus, the constant supply of E2 alone could simulate at least one 4‐day cyclic LH surge in ovariectomized rats. E2 infusion caused a daily peak of FSH synchronized with the LH rises, but could not suppress the post‐operative hypersecretion. It is discussed that if the suppressing effect of progesterone endogenously secreted from the ovaries is cleared, a circadian pattern of the LH/FSH surge may appear under the signal from the cerebral clock mechanism and the effect of circulating estrogen. The failure to suppress the FSH hypersecretion by E2 might indicate the involvement of inhibin in the regulatory mechanism. Time‐course changes in uterine and vaginal weights are also dealt with and discussed in relation to the constant E2 exposure.  相似文献   

14.
Estradiol-benzoate (EB) injected into previously ovariectomized (OVX) rats, increased pituitary ATPase activity 69% over controls, within one hour of treatment. Twelve hours after injection, ATPase activity was not significantly different from controls. Progesterone [(P): 5mg/100gBW] administered in conjunction with EB elicited an analogous response. AT at time of EB and EB+P induced increments in pituitary ATPase activity, plasma LH levels were dramatically reduced to normal, intact diestrous control levels. Post-castrational elevations in FSH were also suppressed after one hour of treatment with EB, but not following EB+P administration. The results suggest that the inhibitory actions of EB and EB+P on post-castrational LH levels may be related to modulation by these steroids of pituitary membrane ATPase activity.  相似文献   

15.
The pituitary gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) regulate steroidogenesis and spermatogenesis by activating receptors expressed by Leydig cells (LH receptor) and Sertoli cells (FSH receptor), respectively. This concept is also valid in fish, although the piscine receptors may be less discriminatory than their mammalian counterparts. The main biological activity of LH is to regulate Leydig-cell steroid production. Steroidogenesis is moreover modulated in an autoregulatory manner by androgens. The male sex steroids (testosterone in higher vertebrates, 11-ketotestosterone in fish) are required for spermatogenesis, but their mode of action has remained obscure. While piscine FSH also appears to have steroidogenic activity, specific roles have not been described yet in the testis. The feedback of androgens on gonadotrophs presents a complex pattern. Aromatizable androgens/estrogens stimulate LH synthesis in juvenile fish; this effect fades out during maturation. This positive feedback on LH synthesis is balanced by a negative feedback on LH release, which may involve GnRH neurones. While the role of GnRH as LH secretagogue is evident, we have found no indication in adult male African catfish for a direct, GnRH-mediated stimulation of LH synthesis. The limited available information at present precludes a generalized view on the testicular feedback on FSH.  相似文献   

16.
The dynamics of follicle-stimulating hormone (FSH) luteinizing hormone (LH), prolactin (PRL), estradiol (E2), and progesterone were studied in left- and right-handed women having a stable 28-day menstrual cycle. The hormones were determined by enzyme immunoassays on days 3, 8, 10, 13, 16, 22, 26, and 28 of the menstrual cycle. The data showed that bllod serum levels of FSH, LH, PRL, and E2are higher in left-handed in comparison to right-handed women (p< 0.001). On days 10 through 28 of the cycle, the level of progesterone is also higher in left-handed women (p< 0.001). The dynamic of these hormones in left-handed and right-handed women appeared to remain within the normal limits. These findings indicate that the handedness correlates with the dynamucs of serum levels of these hormones. Higher serum levels of hormones in left-handed women suggests that they have higher levels of the functional activity of the hypophysis–ovarian axis and prolactin axis.  相似文献   

17.
We determined the dose-response relationship and examined the time related effect of CRF (corticotropin releasing factor) injected directly into the median eminence (ME) on LH and FSH secretion in conscious female rats of different steroid status. Doses of 0.25, 0.75, 1, and 1.5 nM CRF dissolved in 1l of water were injected into the ME in 5 experimental groups of rats: Short-term (2 days) ovariectomized (sOVX); long-term (3–4 weeks) ovariectomized (lOVX); lOVX primed by estradiol benzoate (EB) 4 h before the experiment (lOVX+E); lOVX primed by EB 36 h before the experiment (lOVXE) and lOVX primed by EB 72 h and progesterone 6 h before experiment (lOVXP). Blood was collected at 30, 60, 90, and 120 min postinjection to determine LH and FSH by RIA. CRF at the doses of 0.75, 1, and 1.5 nM significantly decreased serum LH levels in all groups. The dose of 0.25 nM CRF was ineffective. The highest dose (1.5 nM) of CRF had no effect on serum FSH levels. The results suggest that CRF inhibits LH secretion, at least in part, by a central action on GnRH release in the ME, and that this effect is independent of the estrogen/progesterone status of the animal.  相似文献   

18.
Secretory dynamics of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured at various times following gonadectomy in adult male grass frogs, Rana pipiens. Plasma levels and in vitro initial secretory rates of both LH and FSH increased significantly within 1 wk and remained elevated for 3-4 wk of castration. Pituitary FSH and LH content were unchanged. However, dissociation between the two gonadotropins (Gth) occurred thereafter: Secretion of FSH remained elevated for 70 days, but those of LH declined to control levels after 30 days. In vitro secretion of Gth from gonadectomized (gonadx) frogs declined progressively over time reaching control levels after 24 h incubation. The results indicate that elevated pituitary secretion contributes to the observed circulating LH and FSH levels in gonadx frogs, and that FSH and LH may be controlled independently. Replacement therapy with 17 beta-estradiol (E2) suppressed post-gonadectomy increases in plasma Gth and in vitro responses to GnRH, whereas 5 alpha-dihydrotestosterone (DHT) had little effect in vivo and augmented GnRH responses in long-term castrates. In vitro, E2 also inhibited, while 48 h of DHT treatment had no effect on GnRH responsiveness of pituitaries from gonadx frogs. The actions of these steroids were opposite to those typically observed in mammals (and birds), and support the hypothesis that E2 may contribute to seasonal testicular regression in ranid frogs.  相似文献   

19.
摘要 目的:回顾性分析子宫肌瘤剜除术联合腹腔镜下子宫血管阻断术治疗子宫肌瘤的临床疗效。方法:分析2017年6月~2019年7月期间我院收治的子宫肌瘤患者的临床资料(n=150)。根据手术方法的不同将患者分为A组(腹腔镜下子宫肌瘤剜除术治疗,73例)和B组(腹腔镜下子宫血管阻断术联合子宫肌瘤剜除术治疗,77例),对比两组术中、内分泌激素、术后恢复指标、妊娠情况、并发症发生率及复发率。结果:两组患者手术时间对比无统计学差异(P>0.05),B组的术中出血量少于A组,术后排气时间、住院天数、下床活动时间短于A组(P<0.05)。A组术前、术后3个月、术后6个月黄体生成素(LH) 、卵泡刺激素(FSH) 、雌二醇(E2) 水平组内对比无统计学差异(P>0.05)。B组术前、术后3个月、术后6个月E2水平呈降低后升高趋势,LH、FSH水平呈升高后降低趋势(P<0.05)。B组术后3个月LH、FSH水平高于A组,E2水平低于A组(P<0.05)。与A组相比,B组的并发症发生率明显下降,组间对比有差异(P<0.05)。B组的妊娠率高于A组,子宫肌瘤复发率低于A组(P<0.05)。两组流产率组间对比无统计学差异(P>0.05)。结论:与单纯子宫肌瘤剜除术相比,结合腹腔镜下子宫血管阻断术治疗子宫肌瘤患者可减少术中出血量,促进患者术后恢复,降低并发症发生率及复发率,虽然其对卵巢功能有轻微、短暂性影响,但可逐步恢复,且有利于提高妊娠率。  相似文献   

20.
The objective of this study was to expand the data on menstrual cycle serum hormone patterns in female common chimpanzees, both in terms of the number of cycles analyzed and by the addition of data on testosterone levels. Samples were obtained from 11 unanesthetized animals trained for conscious blood withdrawal. LH, FSH, 17β-estradiol (E2), progesterone (P), and testosterone (T) were measured by radioimmunoassay, genital swelling was recorded, and menstrual blood was noted. Concurrent midcycle elevations in LH and FSH and luteal phase elevations in progesterone suggested that the cycles were ovulatory. Detumescence of genital swelling occurred about 3 days after the midcycle LH peak, 1 day after the luteal phase nadir in E2, and 1 day after P levels exceeded 5 ng/ml. These relationships provide further support for the use of genital swelling in monitoring progress of the menstrual cycle. The hormone patterns in the chimpanzees closely resembled those of the human females, but E2 and T levels were higher. The levels of E2 and T were higher and the midcycle elevation in T was broader in the chimpanzee than in gorillas and orangutans. This is of interest because E2 and T are implicated in the regulation of mating, and chimpanzees mate over a greater portion of the cycle than the other apes. These data indicate the need for further study of hormonal contributions to the different patterns of mating in the great apes. They also support the use of the female common chimpanzee as a model for the human female in endocrine studies of the menstrual cycle.  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