共查询到20条相似文献，搜索用时 46 毫秒
1.
Onda K Matsuki N Ono K Wada Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(6):623-625
To examine the PTH/PTHrP receptor in the mammary gland, molecular cloning of bovine PTH/PTHrP receptor and measurement of its mRNA expression were carried out in cows during the periparturient period. The PTH/PTHrP receptor gene was partially cloned, and expression of bovine PTH/PTHrP receptor mRNA was detected in various tissues of the cow. In the mammary gland, PTH/PTHrP receptor mRNA expression was constantly low during the periparturient period, whereas PTHrP mRNA expression dramatically increased after parturition. This suggested that expression of PTH/PTHrP receptor mRNA in the mammary gland is not affected by lactation in cows. 相似文献
2.
Onda K Sato A Yamaguchi M Matsuki N Ono K Wada Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(7):709-713
To investigate the roles of mammary PTHrP in calcium uptake and/or release in the mammary gland of cows, plasma PTHrP and Ca levels, and their arterial-venous differences were examined in a Jersey cow during the periparturient period. Levels of Ca in both abdominal aorta and abdominal subcutaneous vein blood slightly decreased around the parturition and at 24 days after the parturition, however, no remarkable arterial-venous differences were observed. Plasma PTHrP levels in both arterial and venous samples were below the detection limit (0.57 pmol/l) during the experimental period. Milk PTHrP and Ca levels were measured in 9 Holstein dairy cows. Although plasma PTHrP levels in all arterial and venous samples were also below the detection limit, milk PTHrP and Ca levels were remarkably high, ranging from 14,900 pmol/l to 41,200 pmol/l and from 772 mg/l to 1,200 mg/l, respectively. In addition, a significant positive correlation (P<0.01) was observed between milk PTHrP and Ca levels. These results suggested that mammary PTHrP is closely related to Ca concentration in the milk. 相似文献
3.
为探讨脾源性酪氨酸激酶(spleen tyrosine kinase,SYK)的表达与奶牛乳腺发育和泌乳功能之间的关系,试验采用Western blotting和激光共聚焦显微技术对泌乳期高乳品质、低乳品质及干乳期的中国荷斯坦奶牛乳腺组织中SYK的表达含量和表达部位的变化进行研究。结果表明,干乳期奶牛乳腺组织中SYK的表达显著高于泌乳期奶牛乳腺组织(P<0.05),泌乳期高乳品质、低乳品质奶牛乳腺组织中SYK的表达差异不显著(P>0.05);在干乳期SYK主要在乳腺导管上皮细胞的胞质中表达,而在泌乳期SYK在腺泡上皮细胞中表达。结果提示SYK是乳腺上皮细胞增殖与分化的调节因子,主要参与干乳期乳腺组织的重建过程。 相似文献
4.
LIN Lin FAN Hui-quan XING Wei-nan YANG Yang HOU Xiao-ming ZHANG Chang-shun LIN Ye 《中国畜牧兽医》2015,42(5):1240-1244
To investigate the relationship between the expression of SYK and dairy cow mammary gland development and lactation, the expression of SYK in lactating dairy cow mammary gland with high or low quality milk and dry period Holstein dairy cow mammary gland was detected by Western blotting and laser confocal microscope.The results showed that SYK expression in dry period mammary gland was significant higher than that in lactating mammary gland (P<0.05).There was no SYK differential expression detected between lactating mammary gland with high quality milk and low quality milk (P>0.05).SYK was mainly located in the cytoplasm of ductal epithelial cells in dry period mammary gland.In lactating mammary gland, SYK was existed in acinar epithelial cells.All these results revealed that SYK was a regulator in mammary epithelial cell proliferation and differentiation.It participated in mammary gland reconstitution in dry period. 相似文献
5.
Tokushi KOMATSU Fumiaki ITOH Ryosuke SAKUMOTO Koichi HODATE Yoshiaki OBARA Shiro KUSHIBIKI 《Animal Science Journal》2007,78(1):98-102
Glucose delivery and uptake by the mammary gland is a rate‐limiting step in milk synthesis. Insulin resistance is believed to increase throughout the body following the onset of lactation. To study glucose metabolism in peak‐, late‐, and non‐lactating cows we analyzed the expression of an adipokine, namely, adiponectin, decreased insulin resistance, leptin, and a novel insulin‐responsive glucose transporter (GLUT12) in the adipose tissue and mammary gland by using real‐time polymerase chain reaction. Our results demonstrated that the mRNA level of adiponectin in the adipose tissue was greater in non‐lactating cows than in peak‐lactating cows. In the adipose tissue, there were no significant differences in the abundance of GLUT12 mRNA between the peak‐, late‐, and non‐lactating cows. In contrast, in the mammary gland, the mRNA level of GLUT12 was greater in non‐lactating cows than in peak‐ and late‐lactating cows. In the adipose tissue, the mRNA level of leptin and peroxisome proliferator‐activated receptor gamma 2 (PPARγ2) was greater in non‐lactating cows than in peak‐lactating cows. The results of the present study suggest that in lactating cows adiponectin plays an important role in insulin resistance in the adipose tissue; in the mammary gland, GLUT12 expression is believed to be an important factor for insulin‐dependent glucose metabolism. 相似文献
6.
Elsasser TH Capuco AV Caperna TJ Martínez A Cuttitta F Kahl S 《Domestic animal endocrinology》2007,32(2):138-154
Adrenomedullin (AM) has been characterized as an endogenous tissue survival factor and modulator of many inflammatory processes. Because of the increased susceptibility of the mammary gland to infection during the time surrounding parturition in the cow, we investigated how milk and tissue content of AM and its binding protein (AM-BP) might be affected by the stage of lactation and the udder health status. Milk and mammary biopsy samples were obtained from Holstein cows 21 days prior to and at various times after calving to represent the dry period and early and mid-stages of lactation. Additional cows received an intramammary challenge with Escherichia coli for immunohistochemical characterization of AM and AM-BP. Milk AM concentrations were relatively constant across the stages of lactation while AM-BP increased two-fold (P<0.04) between early and mid-lactation. Milk AM (P<0.04) and AM-BP (P<0.03) increased as somatic cell counts (SCCs) increased within a given stage of lactation. Tissue content of both (AM and AM-BP) were significantly affected by stage of lactation, lowest in the dry period and progressively increasing to peak at mid-lactation as well as increasing in association with higher levels of SCCs. Following E. coli challenge, AM increased in epithelial cells surrounding mammary alveoli presenting high levels of SCCs. The data suggest that AM and AM-BP are cooperatively regulated in the mammary gland during lactation; changes in localized tissue AM and AM-BP content reflect a dynamic regulation of these tissue factors in the bovine mammary gland consistent with their protective effects within inflamed tissue. 相似文献
7.
目的:研究荷斯坦奶牛乳腺发育中乳糖的变化规律.方法:高效液相色谱法测定荷斯坦奶牛乳腺发育中乳糖的含量.结果:围产期,乳腺中才出现可检测到的乳糖;泌乳期乳糖含量增高,泌乳140d达到峰值;退化期乳腺乳糖含量迅速降低,退化30d含量很少.结论:不同生理时期,荷斯坦奶牛乳腺中的乳糖含量不同. 相似文献
8.
Presence of mammary-derived growth inhibitor (MDGI) in mammary tissue of lactating and involuted cows was investigated. Eighteen lactating, non-pregnant high-producing Holstein cows were randomly assigned to 3 experimental groups of 6 cows each. Cows of the first group were slaughtered while in lactation. Cows of the second group were slaughtered at 2-3 d, and the others at 4-8 d following sudden cessation of milking. Cessation of milking occurred at approximately 300 d in lactation. Western blot analysis revealed the presence of MDGI in the cytosolic and microsomal fractions of mammary tissue homogenates. High levels of MDGI were detected in mammary tissue obtained from lactating non-pregnant cows. A dramatic reduction in MDGI was observed in early involution (2-3 or 4-8 d following cessation of milking). These data suggest that a relationship exists between MDGI levels and the physiological status of the gland. Lack of MDGI may play a role during the processes of mammary involution and development prior to parturition. 相似文献
9.
Data from 65 cows were collected to clarify the relationship between parity and mineral status in Holstein cows during the periparturient period. Milk fever occurred in a second‐ and a fourth‐lactation cow at parturition. Bodyweight of cows decreased immediately after parturition, and the decreased weights of cows from 1 to 6 days after parturition ranged from 11 to 27 kg. Milk yield of multiparous cows was higher than that of primiparous cows, but Ca and P concentrations in colostrum were not affected by the parity. Plasma glucose of primiparous cows was higher than that of multiparous cows, and plasma nonesterified fatty acids of fourth‐and‐more‐lactation cows at parturition was highest. Plasma Ca concentration of cows at parturition decreased with advancing parity, and plasma inorganic P concentration of third‐and‐more‐lactation cows was lowest at parturition. Plasma parathyroid hormone of fourth‐and‐more‐lactation cows at parturition was highest, but plasma hydroxyproline and alkaline phosphatase was lowest. These results suggest that the large transfer of Ca and P to colostrum is a factor in the development of milk fever in third‐and‐more‐lactation cows. 相似文献
10.
Yoshihisa OHTANI Tatsuyuki TAKAHASHI Katsuyoshi SATO Astrid ARDIYANTI Sang‐Houn SONG Reiichiro SATO Ken ONDA Yasunori WADA Yoshiaki OBARA Keiichi SUZUKI Akihiko HAGINO Sang‐gun ROH Kazuo KATOH 《Animal Science Journal》2012,83(12):788-795
Although our previous report demonstrated that adiponectin and AdipoR1 gene expressions changed among different lactation stages in the bovine mammary gland, its in vivo kinetics remain unclear in ruminant animals. In this study, we investigated the changes in circulating concentrations of adiponectin, as well as other metabolic hormones and metabolites, (i) during the periparturient period and (ii) among different lactation stages, in Holstein dairy cows. In experiment 1, serum adiponectin concentrations increased after parturition. Serum insulin concentrations were lower in the postpartum than prepartum period, whereas serum growth hormone (GH) concentrations increased in the postpartum period. Serum nonesterified fatty acids (NEFA) levels were increased during the postpartum period and were dependent on the parity. In experiment 2, there was no significant difference in plasma adiponectin concentrations among lactational stages. Plasma insulin concentrations tended to be lower in early lactation while plasma GH levels tended to be higher. Plasma NEFA concentrations were significantly lower in mid‐ and late‐lactation stages than non‐lactation stages. These findings indicate that elevation of serum adiponectin might be involved in energy metabolism just around parturition, and might exert its action through regulation of receptor expression levels in target tissues in each lactational stage in Holstein dairy cows. 相似文献
11.
《Domestic animal endocrinology》1996,13(5):399-410
Parathyroid hormone-related protein (PTHrP) is produced by the lactating mammary gland and is present in milk in a biologically active form. The goal of this investigation was to determine if cells cultured from the lactating mammary glands of cows would secrete PTHrP in vitro. Mammary acini were isolated from lactating cows at 1–6 wk after calving, and fresh or cryopreserved mammary acini were cultured for 14 d on Type I collagen. Cultures on thick layers of collagen (2.5 mm) were detached and allowed to contract on Day 6. PTHrP production was measured by N-terminal radioimmunoassay and bioassay (increased cAMP levels in ROS 17/2.8 osteoblast-like cells). The mammary cells reached confluence at Day 6. PTHrP production was low at Day 2 (<0.5 ng/ml) but increased to peak production (2–4 ng/ml) at approximately Day 6 and remained constant until Day 14. Immunoreactive and bioactive PTHrP levels in the culture medium correlated well. The cultures produced lactoferrin (2,000–2,300 ng/ml) and αs1-casein (14–19 ng/ml). Prolactin stimulated PTHrP production approximately 50% on Days 6–14. PTHrP production was increased approximately 100% by treatment with epidermal growth factor (10 ng/ml) for 2 d. Morphologic evaluation of cultures on thick, contracted collagen at Day 14 revealed an inner layer of mammary epithelial cells overlying myoepithelial cells and an outer layer of collagen containing stromal cells. Immunohistochemistry demonstrated positive staining for PTHrP and cytokeratin in both mammary epithelial and myoepithelial cells and a-smooth muscle actin in myoepithelial cells. These data demonstrated that cryopreserved mammary tissue from lactating cows could be cultured in vitro and secreted PTHrP in a regulated manner. This in vitro model will be useful to investigate the function and regulation of PTHrP in the lactating mammary gland. 相似文献
12.
干奶期奶牛不同能量摄入对其肝脏胰岛素受体mRNA表达的影响 总被引：3，自引：0，他引：3
将健康围产期奶牛30头随机分为3组,预产前28 d分别饲喂奶牛标准日粮（能量摄入100%组）、标准日粮增加20%日粮（能量摄入120%组）和标准日粮减少20%日粮（能量摄入80%组）,产后各组奶牛均饲喂标准的产奶日粮,至产后56d结束,采用半定量RT-PCR方法,观测干奶期不同能量摄入水平对围产期健康奶牛肝脏胰岛素受体（IR）基因表达的影响.试验结果表明,干奶期低能饲喂奶牛,产后肝脏IR mRNA表达增加,提示低能饲喂有利于调节奶牛产后血糖平衡. 相似文献
13.
为探讨谷氨酰胺(Gln)在泌乳母猪乳腺组织的正常发育和泌乳功能中的调控作用,研究选用6头大白纯种母猪,于泌乳第21天,采集所有母猪具有正常泌乳功能的乳腺组织用于分离乳腺上皮细胞。采用RT-PCR方法鉴定该细胞为猪乳腺上皮细胞,且具有分泌β-酪蛋白的功能;将纯化后处于对数生长期的乳腺上皮细胞接种到培养板上,分别用含0.20、0.16、0.12、0.08、0.04、0.01、0 mmol/mL Gln的培养液进行培养,检测细胞增殖率及其β-酪蛋白表达量。结果表明:Gln添加量在0.08~0.16mmol/mL范围时可显著促进猪乳腺上皮细胞的增殖(P<0.05),且显著提高其β-酪蛋白表达丰度(P<0.05),其中以0.12 mmol/mL浓度效果最显著。结果提示,适宜浓度的Gln能促进泌乳母猪乳腺组织的发育,并能提高乳蛋白的合成量。 相似文献
14.
为寻找奶牛乳腺上皮细胞亚细胞结构中与泌乳相关的重要蛋白质、从蛋白质水平揭示乳蛋白合成的调控机制,应用双向凝胶电泳技术分离体外培养的蛋氨酸处理组与正常组奶牛乳腺上皮细胞蛋白质,利用Image Maser 2D软件对图谱进行对比分析,基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)和数据库检索鉴定,并采用实时荧光定量PCR技术在mRNA水平上验证2-DE结果。质谱鉴定出8个表达上调的差异蛋白质,大多数差异蛋白质的功能涉及细胞骨架构成、能量代谢等过程。这些差异点的发现为研究奶牛泌乳机理提供了有益的线索。 相似文献
15.
Sato J Sato R Takagi A Goto T Okada K Yasuda J Naito Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):291-293
Eight periparturient Holstein Friesian cows were examined for plasma tartrate-resistant acid phosphatase (TRAP) activity to assess the degree of bone metabolic activity and to evaluate the association between the change in calcium (Ca) concentration and bone metabolism during the periparturient period. Milk fever occurred in 1 of 8 cows just after parturition. Plasma TRAP activities did not markedly change in 5 of 8 cows during the experimental period. The changing rate of Ca between preparturition and just after parturition was under -20% in 3 of 8 cows, and low TRAP activities were observed in 2 of these 3 cows. This study suggests that cows with a low TRAP activity are at risk of developing milk fever in comparison to cows with high TRAP activity. Temporary increases of parathyroid hormone were observed in 7 cows, but not in the cow with milk fever. 相似文献
16.
将年龄、胎次相同，年产奶量大于7000kg的围产期荷斯坦奶牛30头随机分为3组，每组10头，低能量组（Ⅰ组）按中国奶牛营养标准2000年版减少20％日粮（能量摄入80％），高能量组（Ⅱ组）则按此标准增加20％日粮（能量摄入120％），对照组（Ⅲ组）按标准日粮（能量摄入100％）饲喂，试验从产前28d到产后56d结束，分娩后各组均按标准配制相同的泌乳日粮。分别于产前28、14d及产后1、14、28、56d采取肝活体组织。应用内对照RT—PCR方法检测肝脏组织MTPmRNA丰度。结果显示，各组奶牛肝MTPmRNA丰度均呈现先升高后降低的趋势。产后均高于产前，且产后1～28d差异显著（P〈0．01或P〈0．05），而后回降，至56d趋于平稳（P〉0．05）；Ⅲ组肝MTP mRNA丰度在产后1d达到峰值，而Ⅰ组和Ⅱ组在产后14d达到最大值（P〈0．01）；Ⅱ组产后1～28d显著高于I组。产后14d显著高于Ⅲ组（P〈0．01）；Ⅲ组产后1d和28d显著高于Ⅰ组（P〈0．01或P〈0．05）。这些结果表明，围产期奶牛能量摄入水平对肝MTP mRNA丰度有显著影响。 相似文献
17.
18.
Incidence of clinical mastitis is highest at drying off and during the periparturient period. Intramammary Escherichia coli infection in high-yielding cows can show a severe clinical response during the early post-partum period. Severe clinical mastitis is mainly determined by cow factors, in particular the functionality of the circulating polymorphonuclear leukocytes (PMN) which are recruited to the mammary gland during the inflammatory reaction. There is a co-incidence between the periods of highest incidence of clinical mastitis and specific structural changes in the mammary gland. During the periparturient period, marked changes in various systemic and local hormones are related to the secretory state of the mammary gland epithelium (lactogenesis). Estrogen and progesterone induce proliferation of the mammary epithelium throughout gestation and act as survival factors in different tissues, although conflicting data have been reported on their effect on PMN oxidative burst. Somatotropin (STH), responsible for maintenance of lactation in ruminants, has been shown to positively influence innate immunity and a more rapid recovery in milk production of severely affected animals. The concentration of STH, and as a result also IGF-I levels is, however, quite low during early lactation. IGF-I and its regulating binding proteins are associated with cell survival, modulation of apoptosis and functionality of PMN in humans. During early lactation, bio-availability of IGF-I is decreased, which might reduce its stimulating effects on PMN quality and functionality. PRL, concomitantly known as a lactogenic hormone and an immunoregulatory cytokine, has also been associated with modulation of the immune system. It is expected that in periparturient animals, hormone changes could interfere with the immune response and the clinical response of mastitis. 相似文献
19.
Capuco AV Ellis SE Hale SA Long E Erdman RA Zhao X Paape MJ 《Journal of animal science》2003,81(Z3):18-31
A persistent lactation is dependent on maintaining the number and activity of milk secreting cells with advancing lactation. When dairy cows are milked twice daily, the increase in milk yield from parturition to peak lactation is due to increased secretory activity per cell rather than to accretion of additional epithelial cells. After peak lactation, declining milk yield is due to loss of mammary epithelial cells by apoptosis. During lactation, only 0.3% of mammary cells proliferate in a 24-h period. Yet this proliferative rate is sufficient to replace most mammary epithelial cells by the end of lactation. Management practices can influence lactation persistency. Administration of bovine somatotropin may enhance persistency by increasing cell proliferation and turnover, or by reducing the rate of apoptosis. Increased photoperiod may also increase persistency of lactation by mechanisms that are as yet undefined. Increased milking frequency during the first weeks of lactation increases milk yield, even after return to less frequent milking, with increases of approximately 8% over the entire lactation. A mammary cell proliferation response to frequent milking during early lactation appears to be involved. Conversely, advanced pregnancy, infrequent milking, and mastitis increase death of epithelial cells by apoptosis. Regulation of mammary cell renewal provides a key to increasing persistency. Investigations to characterize epithelial cells that serve as the proliferative population in the bovine mammary gland have been initiated. Epithelial cells that stain lightly in histological sections are evident through all phases of mammary development and secretion and account for nearly all proliferation in the prepubertal gland. Characterization of these cells may provide a means to regulate mammary cell proliferation and thus to enhance persistency, reduce the effects of mastitis, and decrease the necessity for a dry period. 相似文献
20.
Padilla L Shibano K Inoue J Matsui T Yano H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(9):883-886
Many animals including cattle can synthesize vitamin C from glucose. The objective of this study was to investigate plasma vitamin C concentration in ketotic cows during the early lactation period because glucose supply for vitamin C synthesis might be limited in these cows. We measured plasma beta-hydroxybutyrate (BHBA) concentration in 118 cows within 2 months after parturition. Subclinical/clinical ketosis was quantitatively determined using a plasma BHBA threshold of 1,200 microM. Plasma glucose concentration was lower in the ketotic cows than in the control cows but plasma vitamin C concentration did not differ between the control and the ketotic cows. Then we measured plasma vitamin C, BHBA and glucose levels in 7 cows during the periparturient period. Plasma BHBA increased and plasma glucose decreased after parturition but plasma vitamin C did not change. These results indicate that plasma vitamin C is not related to the incidence of ketosis in the early lactation period. We suggest that ketotic cows have the ability to produce vitamin C to meet its requirement in the early lactation period although glucose supply is not sufficient for milk production. Vitamin C synthesis is possibly given a high metabolic-priority for glucose in lactating cows. 相似文献