共查询到20条相似文献，搜索用时 31 毫秒
1.
A. Lemor M. Mielenz M. Altmann E. Von Borell H. Sauerwein 《Journal of animal physiology and animal nutrition》2010,94(5):e96-e101
Adipose tissue (AT) expresses adipokines, which are involved in the regulation of energy expenditure, lipid metabolism and insulin sensitivity. Visceral (v.c.) and subcutaneous (s.c.) depots largely differ concerning their metabolic characteristics as to the control of lipolysis and the sensitivity to insulin. The adipokines adiponectin, leptin and visfatin influence lipolysis and insulin sensitivity. Signalling by G‐protein coupled receptor 41 (GPR 41) stimulates leptin release via activation by short‐chain fatty acids. We hypothesized that the metabolic differences between v.c. and s.c. fat depots may also apply to the expression of adiponectin, its receptors, leptin, visfatin, insulin receptor (IR) and GPR 41. Therefore, we aimed to compare the mRNA expression of adiponectin, leptin and visfatin, of the adiponectin receptors 1 and 2 (AdipoR1/2) and IR as well of GPR 41 between several s.c. and v.c. fat depots in sheep. Samples from 10 rams were collected at slaughter (40 kg BW) from three s.c. depots, i.e. close to sternum (s.c.S), close to withers (s.c.W), and at the base of tail (s.c.T), and from two v.c. depots, i.e. from perirenal (v.c.P) and omental (v.c.O) fat. The mRNAs of both adiponectin receptors, as well as IR and putative GPR 41, were higher expressed in v.c. fat than in s.c. fat (p ≤ 0.05). Leptin mRNA abundance was greater in s.c. than in v.c. fat (mean ± SEM: s.c.: 2.55 ± 0.81; v.c.: 0.66 ± 0.21) and also differed among the five separately measured fat depots. Our results show differences in mRNA abundance for leptin, AdipoR1 and R2, as well as for IR and GPR 41 in s.c. compared with v.c. fat, thus confirming the need for individual consideration of distinct fat depots, when aiming to characterize adipose functions in ruminants. 相似文献
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Yoshihisa OHTANI Tomo YONEZAWA Sang‐Houn SONG Tatsuyuki TAKAHASHI Astrid ARDIYANTI Katsuyoshi SATO Akihiko HAGINO Sang‐gun ROH Kazuo KATOH 《Animal Science Journal》2011,82(1):99-106
Although the functions of adiponectin, a differentiated adipocyte‐derived hormone, in regulating glucose and fatty acid metabolism are regulated by two subtypes of adiponectin receptors (AdipoRs; AdipoR1 and AdipoR2), those in ruminants remain unclear. Therefore we examined the messenger RNA (mRNA) expression levels of adiponectin and its receptors in various bovine tissues and mammary glands among different lactation stages, and the effects of lactogenic hormones (insulin, dexamethasone and prolactin) and growth hormone (GH) on mRNA expression of the AdipoRs in cultured bovine mammary epithelial cells (BMEC). AdipoRs mRNAs were widely expressed in various bovine tissues, but adiponectin mRNA expression was significantly higher in adipose tissue than in other tissues. In the mammary gland, although adiponectin mRNA expression was significantly decreased at lactation, AdipoR1 mRNA expression was significantly higher at peak lactation than at the dry‐off stage. In BMEC, lactogenic hormones and GH upregulated AdipoR2 mRNA expression but did not change that of AdipoR1. In conclusion, adiponectin and its receptor mRNA were expressed in various bovine tissues and the adiponectin mRNA level was decreased during lactation. These results suggest that adiponectin and its receptors ware changed in mammary glands by lactation and that AdipoRs mRNA expression was regulated by different pathways in BMEC. 相似文献
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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
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Liu BH Wang PH Wang YC Cheng WM Mersmann HJ Ding ST 《Journal of animal science》2008,86(12):3377-3384
Adiponectin is an adipocyte-derived hormone that can improve insulin sensitivity. Its functions in regulating glucose utilization and fatty acid metabolism in mammals are mediated by 2 subtypes of adiponectin receptors (AdipoR1 and AdipoR2). This study was conducted to determine the effect of fasting on the expression of adiponectin and its receptors. The expression of adiponectin was not affected in s.c. adipose tissue, but adiponectin expression increased in visceral adipose tissue after fasting. In contrast, expression of both AdipoR mRNA was increased in the liver and s.c. adipose tissue of 24-h-fasted pigs compared with fed pigs, but the mRNA in muscle and visceral adipose tissue was not affected by fasting. A third putative adiponectin receptor, T-cadherin, was cloned and the mRNA expression was determined. T-Cadherin has been recognized to act as a vascular adiponectin receptor in vascular endothelial and smooth muscle cells. Our data showed that the expression of T-cadherin was decreased in the muscle of fasted pigs, suggesting that the expression of T-cadherin can be regulated by feeding status. In summary, in young pigs, adiponectin mRNA was up-regulated by fasting in visceral, but not s.c., adipose tissue, whereas AdipoR1 and AdipoR2 mRNA were increased in s.c., but not visceral, adipose tissue. The adiponectin receptor, T-cadherin, was expressed in s.c. and visceral adipose tissue and in muscle, but only muscle mRNA expression was decreased by fasting. 相似文献
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Negative energy balance at the onset of lactation is unfavorably associated with fitness traits in high-producing dairy cows. Angiopoietin-like protein 4 (ANGPTL4) is an adipokine that has been associated with the regulation of lipid metabolism through the inhibition of lipoprotein lipase activity and regulation of lipolysis. Expression of ANGPTL4 messenger RNA (mRNA) increases during early lactation, but its regulation with changing energy status is currently unknown. Accordingly, the objective of this study was to determine whether ANGPTL4 mRNA abundance is responsive to declining energy balance induced by the transition from pregnancy to lactation, feed restriction, and GH administration in lactating dairy cows. The mRNA abundance of leptin, adiponectin, and adiponectin receptor 2 were also measured to compare adipokine mRNA profiles during changes in energy metabolism. Repeated adipose tissue biopsies were taken from different cows during transition from late pregnancy to lactation (n = 26), feed restriction (n = 19), and GH administration (n = 20). As expected, milk yield increased with the onset of lactation and GH administration (P < 0.01) but declined during feed restriction. Energy balance declined in each experiment, resulting in negative energy balance at the onset of lactation and after feed restriction. Abundance of ANGPTL4 mRNA expression increased 2- to 6-fold with declining energy balance in each experiment. Leptin mRNA declined with feed restriction, and adiponectin mRNA decreased with the onset of lactation. The consistency and magnitude of the increase in ANGPTL4 mRNA across multiple models of altered energy balance identifies it as an adipokine that is uniquely responsive to changes in energy balance in the lactating dairy cow. 相似文献
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Sadri H Mielenz M Morel I Bruckmaier RM van Dorland HA 《Journal of animal physiology and animal nutrition》2011,95(6):790-797
The objective was to study changes in plasma leptin concentration parallel to changes in the gene expression of lipogenic- and lipolytic-related genes in adipose tissue of dairy cows around parturition. Subcutaneous fat biopsies were taken from 27 dairy cows in week 8 antepartum (a.p.), on day 1 postpartum (p.p.) and in week 5 p.p. Blood samples were assayed for concentrations of leptin and non-esterified fatty acids (NEFA). Subcutaneous adipose tissue was analysed for mRNA abundance by real-time qRT-PCR encoding for leptin, adiponectin receptor 1 (AdipoR1), adiponectin receptor 2 (AdipoR2), hormones-sensitive lipase (HSL), perilipin (PLIN), lipoprotein lipase (LPL), acyl-CoA synthase long-chain family member 1 (ACSL1), acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN) and glycerol-3-phosphate dehydrogenase 2 (GPD2). Body weight and body condition score of the cows were lower after parturition than before parturition. The calculated energy balance was negative in week 1 and 5 p.p., with higher negative energy balance in week 1 p.p. compared with that in week 5 p.p. On day 1 p.p., highest concentrations of NEFA (353.3 μmol/l) were detected compared with the other biopsy time-points (210.6 and 107.7 μmol/l, in week 8 a.p., and week 5 p.p. respectively). Reduced plasma concentrations of leptin during p.p. when compared with a.p. would favour increasing metabolic efficiency and energy conservation for mammary function and reconstitution of body reserves. Lower mRNA abundance of ACC and FASN expression on day 1 p.p. compared with other biopsy time-points suggests an attenuation of fatty acid synthesis in subcutaneous adipose tissue shortly after parturition. Gene expression of AdipoR1, AdipoR2, HSL, PLIN, LPL, ACSL1 and GPD2 was unchanged over time. 相似文献
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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
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M. Mielenz B. Mielenz S.P. SinghC. Kopp J. HeinzS. Häussler H. Sauerwein 《Domestic animal endocrinology》2013
Adiponectin is an adipose tissue-derived glycoprotein circulating as highly abundant multimers. It regulates glucose metabolism and insulin sensitivity. In ruminants, valid data about serum concentrations and tissue-specific protein expression are lacking, and we, therefore, aimed to generate a polyclonal antibody against bovine adiponectin to apply it in immunodetection. The specificity of the purified anti-adiponectin antibody was established by Western blot analysis with the use of reducing and denaturing conditions applied to both the purified protein and the bovine serum samples. Besides bovine serum, the applicability of the antibody for immunodetection of adiponectin was confirmed for the supernatant fluid of in vitro–differentiated bovine adipocytes, for protein extracts from bovine adipose tissue, and also in a multispecies comparison: bands comparable in size with monomeric bovine adiponectin were obtained under denaturing conditions in serum of camel, horse, human, mouse, pig, roe deer, and sheep. In addition, when used in immunohistochemistry on bovine adipose tissue sections, a characteristic adipocyte-specific staining pattern was obtained with this antibody. The antibody was used for establishing a semiquantitative Western blot procedure and the development of an ELISA. Both methods were extensively validated and were first applied to characterize the serum adiponectin concentrations in multiparous dairy cows during the transition from pregnancy to lactation, that is, 3 wk before until 5 wk after calving. With both assays a time effect (P = 0.017, P = 0.026, respectively) with lowest values at the day of parturition was observed. We thus established 2 useful tools to validly assess bovine adiponectin at the protein level. 相似文献
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冷应激条件下猪脂肪组织中脂联素及其受体 mRNA水平的表达变化 总被引：2，自引：2，他引：0
为了研究冷应激对脂肪代谢的影响,本试验分别在-15~-10 ℃、-10~-5 ℃、-5~0 ℃、15~18 ℃温度条件下采取猪颈部、背部皮下和内脏系膜脂肪组织,通过荧光定量RT-PCR方法检测脂联素及其受体mRNA的表达水平。结果显示,随着冷应激强度的逐渐加大,在颈部、背部皮下、内脏系膜Adiponectin mRNA的表达量逐渐降低,差异显著(P＜0.05);内脏系膜中AdipoR 1和AdipoR 2 mRNA表达量先逐渐升高后恢复正常,且差异极显著(P＜0.01);背部皮下AdipoR 2 mRNA表达量先逐渐降低后恢复正常,差异极显著(P＜0.01),AdipoR 1 mRNA表达量没有明显变化;颈部皮下AdipoR 2 mRNA的表达量先逐渐升高后恢复正常,差异极显著(P＜0.01),AdipoR 1 mRNA的表达量先升高后恢复正常,而后又升高,差异极显著(P＜0.01)。结果表明,脂联素及其受体参与冷应激过程,它们可能与冷应激条件下脂肪组织的重新分布有重要的关系。 相似文献
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PA Accorsi N Govoni R Gaiani C Pezzi E Seren C Tamanini 《Reproduction in domestic animals》2005,40(3):217-223
Leptin may play a role in the endocrine-metabolic processes that guarantee the physiological course of lactation in dairy cattle. This study was aimed at determining the changes in plasma concentrations of leptin and some of the main hormones and metabolites involved in the lactogenetic process in high-yielding dairy cows throughout lactation; we also wanted to assess whether leptin secretion is subjected to seasonal influences. Blood samples were collected from 23 Italian Friesian dairy cows from the end of a lactation to the ninth month of the subsequent one; in addition, blood was sampled from 47 dairy cows in different phases of lactation during February and July. Plasma concentrations of leptin, growth hormone (GH), insulin, prolactin (PRL), glucose, non-esterified fatty acids (NEFA) and urea were quantified by either validated radioimmunoassay (RIA) or enzymatic colorimetric methods. At the beginning of lactation, GH concentrations significantly increased, while a significant reduction occurred in leptin and insulin. This endocrine condition, such as the significant increase in NEFA plasma concentrations, is indicative of a marked lipid mobilization. In the more advanced stages of lactation, when both energy and protein balances become positive, leptin plasma concentrations increased, whereas GH and NEFA concentrations declined. During the summer months, a significant increase in leptin plasma concentrations, irrespective of the phase of lactation, was observed. Collectively, our findings suggest that, in dairy cows, leptin may represent a 'metabolic signal' of animal's status of fattening and nutritional level; in addition, leptin seems to be influenced by photoperiod and environmental temperature. 相似文献
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Adiponectin is an adipocyte-derived hormone that can improve insulin sensitivity. Its functions in regulating glucose utilization and fatty acid metabolism in mammals are mediated by two subtypes of adiponectin receptors (AdipoR1 and AdipoR2). This study was conducted to determine the effect of insulin on the expression of adiponectin and its receptors. We demonstrated that in the presence of 10 nM insulin, addition of 1 μM of insulin or rosiglitazone (a peroxisome proliferator-activated receptor γ (PPARγ) agonist) had no effect on the expression of adiponectin and AdipoR genes in differentiated porcine adipocytes. However, the addition of 1 μM insulin plus 1 μM rosiglitazone significantly increased the AdipoR2 mRNA in differentiated porcine adipocytes. Using the phosphatidylinositol 3-kinase inhibitor (PI3K inhibitor, LY 294002), we found that insulin inhibited the expression of AdipoR2 through the PI3K pathway and this inhibition was blocked by addition of rosiglitazone. When porcine adipocytes were cultured without insulin, supplementation with 10 nM insulin inhibited the expression of AdipoR2 and this inhibition effect was also blocked by addition of rosiglitazone. Therefore, these data suggest that a PPARγ agonist increases expression of AdipoR2 and that insulin inhibits the expression of AdipoR2 through the PI3K pathway. 相似文献
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The objective of this study was to investigate serum lipids, metabolic parameters and activity of the anti-oxidative enzyme paraoxonase-1 (PON1). The study was conducted on non-pregnant heifers with optimal health status and on healthy dairy cows in the period of intensive lactation, assuming that the energy and metabolic demands during lactation reduce anti-oxidative protection. Total cholesterol and HDL-cholesterol concentrations were significantly higher (P < 0.05) in lactating cows than in heifers. Bilirubin concentration and γ-glutamyltransferase (GGT) activity were also significantly higher in lactating cows (P < 0.05), indicating increased hepatic efforts of cows to meet energy requirements for lactation. Significantly lower PON1 activity and PON1/HDL ratio in lactating cows compared to heifers (P < 0.05) showed that metabolic efforts during pregnancy, parturition and lactation influence PON1 activity due to oxidative stress. Concurrent increase in total and HDL-cholesterol during lactation indicated that the HDL particle is a major carrier of cholesterol in cows. 相似文献
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We conducted experiments to evaluate the effects of lipid supplementation and the nature of starchy concentrate on the regulation of leptin synthesis in lactating goats. Multiparous goats in mid- to late lactation received diets based on different forages and containing plant oil or seeds rich in either 18:1c9, 18:2n-6 or 18:3n-3 corresponding to 3%–7% dry matter (DM) as lipid supplements, or diets based on concentrate as either rapidly or slowly degradable starch. The isoenergetic replacement of a part of the concentrate by either oleic sunflower-seed oil, formaldehyde-treated linseeds, or linseed oil did not modify leptinemia and the leptin mRNA concentration in adipose tissues, suggesting a lack of effect of 18:1c9, 18:3n-3, or their biohydrogenation products. Conversely, leptinemia and the leptin mRNA abundance were increased (by 20% and 140%, respectively, P < 0.05) in goats fed sunflower-seed oil under a grassland hay-based diet but not a maize silage-based diet, at similar energy intakes and adiposity. Thus, 18:2n-6 per se may up-regulate leptin gene expression, but the effect could be blunted by other fatty acids formed during the ruminal digestion of sunflower-seed oil when combined with maize silage. Consumption of rapidly but not slowly degradable starch increased (by 17%, P < 0.05) leptinemia. Moreover, during lactation, plasma leptin was positively correlated (P < 0.05) to adiposity parameters and negatively correlated to fiber intake. The results suggest that leptinemia responds poorly to nutritional factors in lactating goats, thus highlighting the physiological need to sustain hypoleptinemia during lactation. 相似文献
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Glucose delivery and uptake by the mammary gland are a rate-limiting step in milk synthesis. It is thought that insulin-independent glucose uptake decreases in tissues, except for the mammary gland, and insulin resistance in the whole body increases following the onset of lactation. To study glucose metabolism in peak-, late-, and nonlactating cows, the expression of erythrocyte-type glucose transporter (GLUT1) and the insulin-responsive glucose transporter (GLUT4) in the mammary gland, adipose tissue, and muscle were assessed by Western blotting and real-time PCR. Our results demonstrated that the mammary gland of lactating cows expressed a large amount of GLUT1, whereas the mammary gland of nonlactating cows did not (P < 0.05). On the other hand, adipose tissue of late and nonlactating cows expressed a large amount of GLUT1, whereas the adipose tissue of peak-lactating cows did not (P < 0.05). There were no significant differences in the abundance of GLUT4 mRNA in adipose tissue and muscle, whereas GLUT4 mRNA was not detected in the mammary gland. The plasma insulin concentration was greater (P < 0.05) in nonlactating cows than in peak- and late-lactating cows. The results of the present study indicate that in lactation, GLUT1 expression in the mammary gland and adipose tissue is a major factor for insulin-independent glucose metabolism, and the expression of GLUT4 in muscle and adipose tissue is not an important factor in insulin resistance in lactation; however, the plasma insulin concentration may play a role in insulin-dependent glucose metabolism. Factors other than GLUT4 may be involved in insulin resistance. 相似文献
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Ed Kabara Lorraine M. SordilloSue Holcombe G. Andres Contreras 《Comparative immunology, microbiology and infectious diseases》2014
The periparturient period of dairy cows is characterized by intense lipid mobilization from adipose tissue leading to increased plasma concentrations of nonesterified fatty acids (NEFA). High NEFA are a predisposing factor for inflammatory based diseases. A major component of these diseases is uncontrolled macrophage/monocyte inflammatory responses. Changes in the endocrine activity of adipose tissue during the periparturient period could impact macrophage function by modifying the secretion of adipokines including adiponectin. Currently, the effects of adiponectin on monocyte activation in dairy cattle are unknown. In humans and rodents, this adipokine regulates monocyte phenotype and alterations in its plasma levels are linked with the development of inflammatory diseases. The objectives of this study were to establish associations between plasma adiponectin expression dynamics and different markers of lipid mobilization during the periparturient period of dairy cows and to characterize the effects of adiponectin on the inflammatory response of bovine monocytes. Plasma adiponectin, NEFA, BHB, albumin, and subcutaneous and retroperitoneal fat depots depth were measured during the periparturient period of dairy cows. In vitro, bovine monocytes were cultured with adiponectin to assess changes in pro-inflammatory responses following LPS stimulation. Results from this study demonstrate that alterations in plasma adiponectin levels in periparturient cattle are inversely correlated with the concentrations of plasma NEFA, an important marker of lipid mobilization. Furthermore, adiponectin exposure significantly decreased monocyte expression of TNFα after LPS stimulation thus markedly reducing their inflammatory response. Reduced plasma adiponectin during the periparturient period could predispose dairy cows to the development of uncontrolled monocyte inflammatory responses. 相似文献