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 46 毫秒
1.
There are few reports describing the structure and function of the whale placenta with the advance of pregnancy. In this study, therefore, the placenta and nonpregnant uterus of the Antarctic minke whale were observed morphologically and immunohistochemically. Placentas and nonpregnant uteri were collected from the 15th, 16th and 18th Japanese Whale Research Programme with Special Permit in the Antarctic (JARPA) and 1st JARPA II organized by the Institute of Cetacean Research in Tokyo, Japan. In the macro- and microscopic observations, the placenta of the Antarctic minke whale was a diffuse and epitheliochorial placenta. The chorion was interdigitated to the endometrium by primary, secondary and tertiary villi, which contained no specialized trophoblast cells such as binucleate cells, and the interdigitation became complicated with the progress of gestation. Furthermore, fetal and maternal blood vessels indented deeply into the trophoblast cells and endometrial epithelium respectively with fetal growth. The minke whale placenta showed a fold-like shape as opposed to a finger-like shape. In both nonpregnant and pregnant uteri, many uterine glands were distributed. The uterine glands in the superficial layer of the pregnant endometrium had a wide lumen and large epithelial cells as compared with those in the deep layer. On the other hand, in the nonpregnant endometrium, the uterine glands had a narrower lumen and smaller epithelial cells than in the pregnant endometrium. In immunohistochemical detection, immunoreactivity for P450scc was detected in most trophoblast cells, but not in nonpregnant uteri, suggesting that trophoblast epithelial cells synthesized and secreted the sex steroid hormones and/or their precursors to maintain the pregnancy in the Antarctic minke whale.  相似文献   

2.
The structure and functions of placentas were examined in 3 species of rorqual whales, common minke (Balaenoptera acutorostrata), Bryde’s (B. brydei) and sei (B. borealis) whales, with the aim of confirming the structural characteristics of the chorion, including the presence of the areolar part, and clarifying steroidogenic activities and fetomaternal interactions in the placentas of these whales. Placentas were collected from the second phase of the Japanese Whale Research Program under Special Permit in the North Pacific (JARPN II). Histological and ultrastructural examinations revealed that these whale placentas were epitheliochorial placentas with the interdigitation of chorionic villi lined by monolayer uninucleate cells (trophoblast cells) and endometrial crypts as well as folded placentation by fold-like chorionic villi. Moreover, well-developed pouch-like areolae were observed in the placentas, and active absorption was suggested in the chorionic epithelial cells of the areolar part (areolar trophoblast cells). Berlin blue staining showed the presence of ferric ions (Fe3+) in the uterine glandular epithelial cells and within the stroma of chorionic villi in the areolar part. An immunohistochemical examination revealed tartrate-resistant acid phosphatase (TRAP; known as uteroferrin in uteri) in the cytoplasm of glandular cells and areolar trophoblast cells. This result suggested that, in cetaceans, uteroferrin is used to supply iron to the fetus. Furthermore, immunoreactivity for P450scc and P450arom was detected in trophoblast cells, but not in areolar trophoblast cells, suggesting that trophoblast cells synthesize estrogen in whale placentas. Therefore, we herein immunohistochemically revealed the localization of aromatase and uteroferrin in cetacean placentas during pregnancy for the first time.  相似文献   

3.
This study aimed to elucidate development of the areola in the early dromedary placenta in comparison with that of the pig and mare. Placental tissues from 25 pregnant camels were obtained from Cairo abattoir and prepared for light, scanning and transmission electron microscopy by routine methods. Vascular casts were made by injection of 4 : 1 liquid plastic mixture of mercox and methylmethacrylate. Areolar formation was first observed at 4.5 cm curved-crown-rump CVR length, while by 5-9 cm CVR length, the endometrial surface was uneven and studded with numerous uterine gland openings, where corresponding foetal areolae were barely detectable and the foetal areolar cells were of variable appearance and covered with long microvilli. At 10-13 cm CVR length the uterine gland openings developed irregular folds and the maternal areolar cells showed numerous apical blebs. At 14-29 cm CVR length the foetal areolae showed a great increase in height at the expense of their width. At 30-34 cm (CVR) length the maternal areolae appeared discoid and sharply demarcated from the surrounding inter-areolar tissues and the foetal areolae were rounded to irregular in shape with well-developed areolar rims. The vascular casts showed a widely meshed capillary network on the maternal areola, connecting with the pre- and post-capillary vessels, whereas the foetal side showed a relatively dense capillary meshwork. These studies indicate that the areola in the placenta of the one-humped camel is of the regular type like in the pig, and is poorly vascularized.  相似文献   

4.
The present study represents the first comprehensive investigation of the glandular chambers of the placenta of the bitch. We examined the glandular chambers by SEM, TEM, ultrahistochemical and lectinhistochemical methods. The glandular epithelium is a high columnar epithelium with club-shaped apical protrusions bearing short microvilli. The epithelium forms extensive folds which fill up most of the lumen of the glandular chambers. Proceeding to the placental labyrinth, the glandular chambers are covered by the tips of the chorionic tufts. The trophoblast and the glandular epithelium are separated by a thick layer of secretions. The ultrastructure cytology of the columnar epithelium is characterized by several Golgi complexes and abundant apical-located mucus vesicles with a positive dialysed iron reaction. Lectin histochemistry reveals in general a strong reaction of these mucus vesicles with all lectins used. The mucus in the lumen of the glandular chamber reacts strongly with WGA. NeuWGA, LPA and ConA. The trophoblastic villi projecting into the lumen of the glandular chambers are covered by a pseudostratified epithelium consisting of a flat basal layer and a superficial columnar one. Its cytoplasm is filled with large fusing vacuoles containing longish screw-shaped structures. No morphological equivalent of absorption is found. According to the ultrastructure of the trophoblast, the significance of the mucus in the glandular chambers in stopping the invasive growth of the trophoblast is discussed.  相似文献   

5.
Cystic follicle is anovulatory follicular structure that is caused by an endocrine imbalance. The activity of cytochrome P450‐side chain cleavage (P450scc) is essential for the initiation of steroidogenesis in the follicle. The present study was designed to compare the frequency of cells containing P450scc between healthy and atretic small antral follicles, and among several types (I, II and III, classified based on the presence of granulosa layer) of cystic follicles. Paraffin sections of healthy (2–5 mm in diameter), atretic (2–5 mm) and cystic follicles (>25 mm) were immunohistochemically stained with rabbit polyclonal antibody to bovine P450scc. The P450scc‐positive cells were counted in four different regions of the follicles from the apical to the basal side. In small antral follicles and cystic follicles, P450scc‐positive cells were localized in the theca interna layers but not granulosa layers. The P450scc‐positive cell populations decreased in the late atretic follicles compared with the early and advanced atretic follicles at all the regions of follicle. Type III cystic follicles showed significantly lower frequencies of P450scc‐positive cells than those in the types I and II cystic follicles. These results suggest that in both small and cystic follicles in cows, total loss of granulosa cells may be associated with the reduction of frequency of P450scc‐positive cells in theca interna layer.  相似文献   

6.
To study the luteal and placental function of pinnipeds, we analyzed the localization of steroidogenic enzymes (P450scc, 3 beta HSD and P450arom) in the corpus luteum and the placenta of ribbon seals (Phoca fasciata) and Steller sea lions (Eumetopias jubatus) immunohistochemically. P450scc and 3 beta HSD were present in all luteal cells of both species. Almost all of the luteal cells were immunostained for P450arom, while P450scc and 3 beta HSD were negatively immunostained in placentae and P450arom was present in the syncytiotrophoblast of placentae. These findings suggest that 1) corpora lutea of both species synthesize pregnenolone, progesterone and estrogen during the entire pregnancy period, and 2) like other terrestrial carnivores in the suborder Caniformia, placentae of both species do not have the capability for synthesizing progesterone in the latter half of active pregnancy period.  相似文献   

7.
Expression of mRNAs encoding cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 -hydroxylase (P450c17), and cytochrome P450 aromatase (P450arom) were characterized by the RT-PCR technique and concentrations of progesterone (P4), testosterone (T0) and estradiol (E2) were measured by radioimmunoassay during follicular development of prepubertal goats. Synthesis of mRNAs encoding P450scc and P450c17 began in preantral follicles, but mRNA encoding P450arom was not detectable until early antral formation. While mRNA for P450scc was expressed in both theca and granulosa cells, mRNA for P450c17 was expressed only in theca cells while P450arom mRNA only in granulosa cells. In nonatretic follicles from prepubertal ovaries, the relative quantity of mRNA expression of all the three enzymes increased with follicle size; however, while the concentration of P4 and E2 increased, that of T0 decreased with follicle size. While expression of mRNA encoding P450scc was unaffected, that of P450c17 mRNA decreased to the lowest level and mRNA for P450arom became undetectable following atresia; accordingly, while the concentration of P4 increased in the atretic medium follicles, that of T0 and E2 decreased to the lowest level after atresia. While the adult follicular stage follicles showed a similar cytochrome expression as the nonatretic follicles of prepubertal goats, the former contained higher levels of E2 and P4 than the latter. The presence of corpus luteum in an ovary decreased expression of P450scc, significantly in large follicles while it increased concentration of P4. These findings indicated that (1) similar to other species, changes in follicular steroid production in goats were explained in large measure by changes in steroidogenic enzyme expression; (2) while mRNA expression was similar, activities of some of the steroidogenic enzymes may differ between sexually mature and immature goats.  相似文献   

8.
Previous anatomical and histochemical studies suggested that interstitial cells were the only steroidogenic cells in the theca layer of small follicles of the chicken ovary. However, the precise cellular site of steroid production in the small follicles is not certain. Therefore, our goal was to identify steroidogenic cells in small follicles (< 10 mm in diameter) of the chicken ovary which have not entered the follicular hierarchy by localizing steroidogenic enzymes with immunocytochemistry. Polyclonal antisera used were anti-cholesterol side-chain-cleavage cytochrome P450 (P450scc), anti-17-hydroxylase cytochrome P450 (P450c17), and anti-aromatase cytochrome P450 (P450arom) for pregnenolone-, androgen-, and estrogen-producing cells, respectively. Ovaries were collected 2 hr after oviposition and embedded in Paraplast after fixation with 4% paraformaldehyde, 10% formaldehyde, or Bouin's solution. Tissues were sectioned (4–6 μm) and sections were mounted on poly-L-lysine coated slides. Sections were incubated overnight at room temperature with each specific antiserum raised in rabbits against cytochrome P450 steroidogenic enzymes or normal rabbit serum as a control and were immunostained with an avidin-biotin-peroxidase complex. Immunoreactivity for the P450 enzymes was absent in the granulosa layer but was present in the theca layer of the small follicles (< 10 mm in diameter). Interstitial cells in the single theca layer of cortical follicles embedded in the ovarian cortex (less than 1 mm in diameter) contained P450scc and P450c17. Cells which contained P450arom, identified as aromatase cells, surrounded the interstitial cells in the theca layer. In small white follicles (approximately 1 mm in diameter), large white follicles (approximately 2–4 mm in diameter), and small yellow follicles (approximately 5–10 mm in diameter) which protruded from the surface of the ovary, the theca layer is divided into the theca interna and the theca externa. P450scc and P450c17 were localized in interstitial cells in the theca interna and externa whereas P450arom was localized in aromatase cells of the theca externa. With follicular development, more interstitial cells staining for P450scc and P450c17 appeared in the theca interna than in the theca externa whereas aromatase cells staining for P450arom were localized only in the theca externa. The distance between interstitial cells and aromatase cells within the theca layer increased as the follicles matured, resulting in a change in the anatomical relationship of steroidogenic cells. Our results of immunolocalization of cytochrome P450 steroidogenic enzymes in developing small follicles suggest that: 1) granulosa cells in small follicles are steroidogenically inactive; 2) steroids are produced in two distinct cell populations in the theca layer of small follicles, namely interstitial cells and aromatase cells; and 3) the anatomical relationship and location of interstitial cells and aromatase cells in the theca layer change with follicular maturation (a two-cell model for steroidogenesis in small follicles during follicular development).  相似文献   

9.
In this study, we performed immunohistochemistry of cholesterol side-chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase (3betaHSD), cytochrome 17alpha-hydroxylase P450 (P450c17), and cytochrome P450 aromatase (P450arom) in the corpus luteum and placenta of Shiba goats. The aim was to clarify the steroidogenic capability of the corpus luteum and placenta of Shiba goats. Ovaries containing corpora lutea were obtained from four adult Shiba goats during the luteal phase (day10; n=2) and pregnancy (90 and 120 days of gestation). Placenta was obtained from one Shiba goat on day 120 of gestation. The sections of the ovaries and placentae were immunostained using the avidin-biotin-peroxidase complex method (ABC) with polyclonal antibodies generated against steroidogenic enzymes of mammalian origin. All luteal cells expressed P450scc, 3betaHSD, P450c17 and P450arom. The distribution of P450scc, 3betaHSD, P450c17 and P450arom were not different during the luteal phase and pregnancy. P450arom showed a weak positive staining in late pregnancy (120 days). In addition, immunoreactions for P450c17 and P450arom were observed in syncytiotrophoblast of the placenta of one Shiba goat. These results indicate that, in Shiba goats, corpus luteum is not only an important source of progesterone but also has the ability to synthesize androgen and estrogen during the luteal phase and pregnancy. Also the placenta has the ability to synthesize androgen and estrogen in late pregnancy.  相似文献   

10.
To study luteal function in the late gestational period of Phocidae (seals), we analyzed the localization of steroidogenic enzymes (P450scc, 3betaHSD and P450arom) and prolactin receptors in the corpora lutea of pregnant spotted seals (Larga seal; Phoca largha) immunohistochemically. P450scc, 3betaHSD and prolactin receptors were present in all luteal cells of each corpus luteum, and most luteal cells were immunostained for P450arom. Although we analyzed only two specimens, P450scc, 3betaHSD and prolactin receptors were negatively immunostained in the placentae. P450arom was present in the syncytiotrophoblast of placentae. These findings suggest that 1) the corpus luteum of the spotted seal synthesizes pregnenolone, progesterone and estrogen during late gestational period, 2) the placenta of this species do not possess the capacity to synthesize progesterone, and 3) like other terrestrial carnivores, this species requires prolactin to maintain the corpus luteum during pregnancy. These characteristics support the recent classification of family Phocidae in the order Carnivora, and suggest a relationship between prolactin and reproductive failure during the post-implantation period in pinnipeds.  相似文献   

11.
We analyzed the localization of steroidogenic enzymes (P450 scc, 3 beta HSD, P450 arom and P450 c17) in the corpora lutea of two Hokkaido sika deer (Cervus nippon yesoensis) during the early mating season. Two corpora lutea were found in each female and the timing of formation of the corpora lutea seemed different. P450 scc, and 3 beta HSD, positive luteal cells were found in both corpora lutea. The existence of two functional corpora lutea from the early mating season through pregnancy suggests that progesterone secreted by two or more corpora lutea is necessary for maintenance of pregnancy in sika deer.  相似文献   

12.
Apart from estrone-3-sulfate (E1S) the bovine placenta produces progesterone (P4), though the corpus luteum is the major source of P4 responsible for maintaining pregnancy. So far the biological function of placental steroids in cattle is largely unknown. However, since the local availability of free estrone (E1) in the placenta seems to be controlled by sulfatase and sulfotranferase, the hypothesis was developed that placental estrogens and P4 might act as local regulatory factors. To test for such a function placentomes from 150, 220, 240, 270 days (D) pregnant and parturient cows were screened immunohistochemically for progesterone and estrogen receptors (PR, ER). PR were found at all stages in the caruncle in stromal cells and capillary pericytes but only at parturition in arterial walls. Percentage of PR-positive caruncular stromal cells (CSC) increased (P<0.05) from 51.8+/-2.6% at D150 to 58.9+/-1.8% at parturition. ER were detected in CSC, caruncular epithelial (CE) cells and in caruncular capillary pericytes. Mean percentage of ER-positive CSC decreased from 39.0+/-5.9% in pregnant cows to 17.5+/-8.3% at parturition (P<0.05). In CE all cells exhibited positive signals with the exception of those immediately surrounding large primary chorionic villi. Proliferation was assessed immunohistochemically by determining the percentage of Ki67-antigen positive cells. Highest values (P<0.001) were obtained for CE (58.0-68.3%), followed by the trophoblast (23.3-25.4%), CSC (10.6-45.3%) and the stroma of the chorionic villi (2.9-10.5%). A transient depression of proliferation in CSC between D150-270 (P<0.05) paralleled local estrogen tissue concentrations. The results suggest that placental estrogens and P4 are important factors controlling caruncular growth, differentiation and function.  相似文献   

13.
Pregnant goats were inoculated intravenously or in uterine arteries with Brucella abortus, and tissues from the uterus and placenta were examined by electron microscopy. Identification of B. abortus in placentae was with antibody-coated colloidal gold. B. abortus was first seen in phagosomes of erythrophagocytic trophoblasts and in the rough endoplasmic reticulum of chorioallantoic trophoblasts. Subsequently, trophoblast necrosis and ulceration of chorioallantoic membranes were present. Coincidently, B. abortus was present in the lumen of placental capillaries. In late stages of infection, placental vasculitis was present, and placentomal trophoblasts were separated from maternal syncytial epithelium. In lesions with vasculitis, large numbers of B. abortus were in connective tissue of chorionic villi. Within the placentome, trophoblasts that lined chorionic villi contained no intracellular bacteria and were separated from B. abortus by intact basement membranes. These results suggest that bacteremic B. abortus is endocytosed by erythrophagocytic trophoblasts and that B. abortus replicates in the rough endoplasmic reticulum of chorioallantoic trophoblasts. Replication of brucellae in trophoblastic rough endoplasmic reticulum is unique; we believe that B. abortus may utilize endoplasmic reticulum for synthesis and glycosylation of bacterial membrane proteins or that B. abortus catabolizes trophoblast secretory proteins.  相似文献   

14.
The objective of this study was to investigate immunolocalization of steroidogenic enzymes in G?ttingen miniature (GM) pig testes. Testes of 6 adult GM pigs were obtained in September 1996 (n=2), February (n=2) and June (n=2), 1997. Steroidogenic enzymes were immunolocalized using polyclonal antisera raised against bovine adrenal cholesterol side-chain cleavage cytochrome P450 (P450scc), human placental 3beta-hydroxysteroid dehydrogenase (3betaHSD), porcine testicular 17alpha-hydroxylase cytochrome P450 (P450c17), and human placental aromatase cytochrome P450 (P450arom). Histologically, all types of spermatogenic cells including mature-phase spermatozoa in seminiferous tubules were observed in all testes throughout the year. Moreover, P450scc, 3betaHSD, P450c17and P450arom were identified in Leydig cells but not in Sertoli cells of all testes. These results suggested that adult GM pig testes have the ability to produce germ cells throughout the year, and the synthesis of progestin, androgen and estrogen occurs in the Leydig cells of GM pig testes.  相似文献   

15.
Embryos of Clinus dorsalis absorb nutrients from the embiyotrophe, secreted by the follicular epithelium. Autoradiographic studies revealed that the principal areas of nutrient absorption are the embryonic gut and epidermis. A histological and electron microscopic study of embryonic structure revealed an extensively hypertrophied gut with numerous flngerlike villi projecting into the gut lumen. A brushborder of microvilli is, furthermore, characteristic of the columnar gut epithelium. Epidermal surface area is increased apically on individual epidermal cells, particularly on the ventral pericardial surface. Micro ridges further increase epidermal surface area. Epidermal surface area is reduced and a mucous layer is secreted prior to parturition.  相似文献   

16.
We investigated the distribution of 3 types of steroidogenic enzymes, P450scc, 3betaHSD, and P450c17, in wild raccoon dog ovaries by immunohistochemistry. Six pairs of ovaries were obtained from wild raccoon dogs between 2001 and 2003, with 3 of the 6 pairs of ovaries containing corpora lutea. P450scc, 3betaHSD, and P450c17 were localized in the granulosa and theca cells of these raccoon dogs. Furthermore, lutein cells were stained positively for P450scc and 3betaHSD in the pregnant and non-pregnant raccoon dogs. These results suggest that granulosa and theca cells may synthesize progesterone and androgens, which may play an important role in follicular development, and that lutein cells are a major source of progesterone in wild raccoon dogs.  相似文献   

17.
A three‐year‐old intact female Old English sheepdog was presented for evaluation of infertility. A uterine biopsy was performed during dioestrus, and the microscopic appearance was inconsistent with progesterone stimulation; the glands were sparse, simple and failed to show coiling, while the glandular epithelium was cuboidal instead of columnar. There was very little evidence of glandular activity. Due to the inappropriate appearance of the glands for the stage of the cycle, immunohistochemistry for progesterone receptors was performed. No progesterone receptor‐positive immunoreactivity was identified in the endometrial luminal epithelium, glandular epithelium or stroma. Weak intranuclear immunoreactivity was identified within the smooth muscle cells of the myometrium. The absence of progesterone receptors within the endometrial glands is the most likely explanation for the abnormal appearance of the endometrium and for this bitch's infertility. To our knowledge, this is the first report of endometrial progesterone receptor absence in a bitch.  相似文献   

18.
Various age groups of turkeys, White Leghorn chickens, and broiler chickens were inoculated with turkey rotavirus strain Tu-2 or with chicken rotavirus Ch-2, and the development of rotavirus-induced lesions were evaluated macroscopically and microscopically (light microscopy and scanning electron microscopy). Morphometric evaluations were conducted to determine morphologic changes in the villi of infected turkeys. Macroscopic lesions that were found in turkeys, but not in chickens, consisted of pallor of the intestinal tract and distension of the cecum with frothy or nonfrothy fluid contents. Histologic lesions in turkeys consisted of basal vacuolation of enterocytes, separation of enterocytes from the lamina propria (with subsequent desquamation), villus atrophy accompanied by widening of the lamina propria, scalloping of the villus surface, fusion of the villi, and leukocytic infiltration of the lamina propria. Scanning electron microscopy indicated roughened villus surfaces, distortion of the normal morphologic features of the villi, and loss of microvilli in cells located on the tips of the villi. Most of the lesions disappeared by 8 days after inoculation. Results of the morphometric evaluations indicated that the crypt length had increased and the villus-to-crypt ratio had significantly decreased, compared with that of noninoculated control turkeys. Broilers greater than or equal to 21 days old and White Leghorn chickens greater than or equal to 35 days old had minimal leukocytic infiltration of the lamina propria and minimal loss of microvilli in cells located on the tips of the villi. The loss of microvilli was more extensive in chickens greater than or equal to 119 days old than in younger birds. Generally, turkeys 1 to 112 days old developed more severe lesions than did chickens, and lesions were more pronounced in turkeys at 112 days of age.  相似文献   

19.
本试验旨在研究维生素E对绵羊原代睾丸间质细胞睾酮合成的影响。选择2月龄杜×寒杂交公羔,屠宰后取睾丸组织。分离绵羊睾丸间质细胞,随机分为4个处理组,每个处理组3皿,培养基内添加不同浓度维生素E(0、40、80、160μg/m L)。培养结束后,测定培养基上清睾酮含量,将细胞裂解测定睾酮合成相关酶3β-羟基类固醇脱氢酶(3β-HSD)、17β-羟基类固醇脱氢酶(17β-HSD)、胆固醇侧链裂解酶(P450scc)、17α-羟化酶(CYP17)以及睾酮合成相关基因3β-HSD、17β-HSD、P450scc、CYP17、类固醇合成急性调节蛋白(St AR)基因相对表达量。结果表明:与对照组相比,添加40μg/m L维生素E有提高绵羊睾丸间质细胞睾酮分泌量的趋势(P=0.061),添加40μg/m L维生素E能显著提高P450scc和3β-HSD酶含量(P0.05),P450scc m RNA与3β-HSD m RNA相对表达量也显著提高(P0.05)。  相似文献   

20.
The testes from 15 adult male Hokkaido Sika deer (Cervus nippon yesoensis) were collected during the rutting season (October and November). We investigated the localization of 4 kinds of steroidogenic enzymes (P450scc, 3betaHSD, P450c17 and P450arom) immunohistochemically in these testicular samples. The specific immunoreactivities to these enzymes were detected only in the cytoplasm of Leydig cells. This differs to the enzyme distributions reported previously in Japanese black bear, Japanese raccoon dog, Hokkaido brown bear and American black bear, in which the same immunoreactivities were detected in Leydig cells, Sertoli cells and/or spermatogenic cells. The current study suggests that in the testes of the Hokkaido Sika deer, testosterone and estradiol-17beta may be synthesized in the Leydig cells only.  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