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Effects of butyrate− on ruminal Ca2+ transport: evidence for the involvement of apically expressed TRPV3 and TRPV4 channels. Pflugers Arch 2022; 474:315-342. [PMID: 35098357 PMCID: PMC8837523 DOI: 10.1007/s00424-021-02647-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/04/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022]
Abstract
The ruminal epithelium absorbs large quantities of NH4+ and Ca2+. A role for TRPV3 has emerged, but data on TRPV4 are lacking. Furthermore, short-chain fatty acids (SCFA) stimulate ruminal Ca2+ and NH4+ uptake in vivo and in vitro, but the pathway is unclear. Sequencing of the bovine homologue (bTRPV4) revealed 96.79% homology to human TRPV4. Two commercial antibodies were tested using HEK-293 cells overexpressing bTRPV4, which in ruminal protein detected a weak band at the expected ~ 100 kDa and several bands ≤ 60 kDa. Immunofluorescence imaging revealed staining of the apical membrane of the stratum granulosum for bTRPV3 and bTRPV4, with cytosolic staining in other layers of the ruminal epithelium. A similar expression pattern was observed in a multilayered ruminal cell culture which developed resistances of > 700 Ω · cm2 with expression of zonula occludens-1 and claudin-4. In Ussing chambers, 2-APB and the TRPV4 agonist GSK1016790A stimulated the short-circuit current across native bovine ruminal epithelia. In whole-cell patch-clamp recordings on HEK-293 cells, bTRPV4 was shown to be permeable to NH4+, K+, and Na+ and highly sensitive to GSK1016790A, while effects of butyrate− were insignificant. Conversely, bTRPV3 was strongly stimulated by 2-APB and by butyrate− (pH 6.4 > pH 7.4), but not by GSK1016790A. Fluorescence calcium imaging experiments suggest that butyrate− stimulates both bTRPV3 and bTRPV4. While expression of bTRPV4 appears to be weaker, both channels are candidates for the ruminal transport of NH4+ and Ca2+. Stimulation by SCFA may involve cytosolic acidification (bTRPV3) and cell swelling (bTRPV4).
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2
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Grimm LM, Humann-Ziehank E, Zinne N, Zardo P, Ganter M. Analysis of pH and electrolytes in blood and ruminal fluid, including kidney function tests, in sheep undergoing long-term surgical procedures. Acta Vet Scand 2021; 63:43. [PMID: 34775972 PMCID: PMC8591915 DOI: 10.1186/s13028-021-00611-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The physiology of sheep as small ruminants is remarkably different from monogastric animals especially regarding the forestomach system. Using sheep for surgical procedures during scientific research thereby presents an exceptional setting for the anaesthetist. Long-term anaesthesia generally demands deprivation of food to reduce the risk of bloat in sheep. This might influence the energy and electrolyte balance. In horses and companion animals, close monitoring of mean arterial blood pressure, capnography and blood gas analysis are common procedures during long-term surgery. However, few data are available on reference ranges for blood gas in sheep and these cover only short periods of anaesthesia. To the authors' knowledge, there is no study available that includes the monitoring of electrolytes and pH in ruminal fluid and kidney function tests in sheep undergoing long term anaesthesia. Thereby, the aim of the present study was to gather data on blood parameters, and data on ruminal fluid and kidney function during long-term anaesthesia in sheep. Data were obtained from eight sheep undergoing the invasive surgical procedure of left pneumonectomy and auto-transplantation or isolated left lung perfusion. After a 19-h fasting period, the animals were administered xylazine and ketamine and then intubated and maintained in general anaesthesia under artificial ventilation using isoflurane in oxygen. Blood samples were evaluated during 9 h of anaesthesia; ruminal fluid and kidney function tests were evaluated during 7 h of anaesthesia. RESULTS Blood parameters such as electrolytes and partial pressure of carbon dioxide revealed few changes, yet blood glucose decreased and beta-hydroxybutyric acid increased significantly. All animals showed an elevated arterial pH and bicarbonate concentration despite artificial ventilation. In ruminal fluid, the pH significantly decreased and no significant changes in electrolytes occurred. Kidney function tests revealed no significant changes in any of the animals. However, fractional excretion of water and phosphate was slightly increased. One animal showed severe complications due to hypokalaemia. CONCLUSION Invasive surgery under long-term anaesthesia in sheep is possible without great imbalances of arterial pH and electrolytes. Nevertheless, potassium concentrations should be monitored carefully, as a deficiency can lead to life-threatening complications. The operated sheep tended not to develop metabolic acidosis and the mean kidney function could be maintained within the physiological range throughout anaesthesia. However, slight elevations in renal fractional water and phosphate excretion could suggest an early tubular reabsorption dysfunction. In ruminal fluid, acidification occurred, though no significant changes were observed in L- and D-lactate levels or in electrolyte concentrations. To our knowledge, the role of the rumen in storing fluids and balancing electrolytes in the blood has not yet been documented during anaesthesia. However, the importance of the rumen for fluid equilibrium in sheep indicates the necessity for routine monitoring and further research.
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Affiliation(s)
- Lucie M Grimm
- Clinic for Swine, Small Ruminants and Forensic Medicine, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany.
| | - Esther Humann-Ziehank
- LABVETCON, Laboratory Veterinary Consulting, Föhrenkamp 20, 31303, Burgdorf, Germany
| | - Norman Zinne
- Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Patrick Zardo
- Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Martin Ganter
- Clinic for Swine, Small Ruminants and Forensic Medicine, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
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3
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Geiger S, Patra AK, Schrapers KT, Braun HS, Aschenbach JR. Menthol stimulates calcium absorption in the rumen but not in the jejunum of sheep. J Dairy Sci 2020; 104:3067-3081. [PMID: 33358813 DOI: 10.3168/jds.2020-19372] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022]
Abstract
Stimulation of Ca2+ absorption can counteract hypocalcemia at the onset of lactation. The plant bioactive lipid compound (PBLC) menthol is an agonist for nonselective cation channels of the transient receptor potential (TRP) family. It acutely stimulated Ca2+ absorption in ruminal epithelia of nonadapted animals ex vivo and caused higher plasma Ca2+ concentrations in cows and sheep in vivo. To elucidate the pathway by which menthol feeding increases plasma Ca2+ level, the present study aimed to investigate the long-term dose-dependent effects of dietary menthol-rich PBLC on Ca2+ absorption and mRNA abundances of TRP channels in both rumen and jejunum. Twenty-four growing Suffolk sheep were equally distributed to a Con, PBLC-L, and PBLC-H group, which received 0, 80, and 160 mg/d of a menthol-rich PBLC. After 4 wk, ruminal and jejunal epithelia were analyzed for mRNA abundances of TRPA1, TRPV3, TRPV5-6, and TRPM6-8 genes. The Ca2+ flux rates and electrophysiological properties of epithelia from rumen and mid-jejunum were measured in Ussing chambers in the presence and absence of mucosal Na+. Acute changes in Ca2+ flux rates were measured after mucosal application of 50 µM menthol. Ruminal epithelia had quantifiable transcripts of TRPV3 = TRPM6 >TRPM7 >TRPA1 with no difference among feeding groups. Jejunum had quantifiable transcripts of TRPM7 >TRPA1 ≥ TRPM6 ≥ TRPV6 >TRPV5, where TRPA1, TRPV5, and TRPV6 tended to decrease linearly with increasing PBLC dose. Absorptive net flux of Ca2+ was detected only in the rumen, whereas jejunum showed a high passive permeability to Ca2+. Net flux rates of Ca2+ in the rumen increased in a quadratic manner (highest in PBLC-L animals) and were systematically decreased with the omission of mucosal Na+. Short-circuit current increased in both PBLC feeding groups compared with Con only in the rumen. Acute application of menthol-stimulated mucosal-to-serosal and net Ca2+ flux rates only in ruminal epithelia with higher stimulation in PBLC-fed animals. We conclude that Ca2+ transport is mainly active and transcellular in the rumen. It most likely involves TRPV3 that can be stimulated by menthol. Pre-feeding of menthol-rich PBLC enhances ruminal Ca2+ absorption and sensitizes it to acute stimulation by menthol. By contrast, intestinal Ca2+ absorption is not sensitive to menthol stimulation. Menthol could be used as a tool to enhance ruminal Ca2+ absorption and to prevent hypocalcemia in dairy cows.
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Affiliation(s)
- S Geiger
- Institute of Veterinary Physiology, Freie Universität Berlin, D-14163 Berlin, Germany
| | - A K Patra
- Institute of Veterinary Physiology, Freie Universität Berlin, D-14163 Berlin, Germany; Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, 700037 Kolkata, India
| | | | - H S Braun
- PerformaNat GmbH, D-14163 Berlin, Germany
| | - J R Aschenbach
- Institute of Veterinary Physiology, Freie Universität Berlin, D-14163 Berlin, Germany.
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4
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Review: Regulation of gastrointestinal and renal transport of calcium and phosphorus in ruminants. Animal 2020; 14:s29-s43. [PMID: 32024566 DOI: 10.1017/s1751731119003197] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In comparison to monogastric animals, ruminants show some peculiarities in respect to the regulation of mineral homeostasis, which can be regarded as a concerted interplay between gastrointestinal absorption, renal excretion and bone mobilisation to maintain physiological Ca and phosphate (Pi) concentrations in serum. Intestinal absorption of Ca or Pi is mediated by two general mechanisms: paracellular, passive transport dominates when luminal Ca or Pi concentrations are high and transcellular. The contribution of active transport becomes more important when dietary Ca or Pi supply is restricted or the demand increased. Both pathways are modulated directly by dietary interventions, influenced by age and regulated by endocrine factors such as 1,25-dihydroxyvitamin D3. Similar transport processes are observed in the kidney. After filtration, Ca and Pi are resorbed along the nephron. However, as urinary Ca and Pi excretion is very low in ruminants, the regulation of these renal pathways differs from that described for monogastric species, too. Furthermore, salivary secretion, as part of endogenous Pi recycling, and bone mobilisation participate in the maintenance of Ca and Pi homeostasis in ruminants. Saliva contains large amounts of Pi for buffering rumen pH and to ensure optimal conditions for the rumen microbiome. The skeleton is a major reservoir of Ca and Pi to compensate for discrepancies between demand and uptake. But alterations of the regulation of mineral homeostasis induced by other dietary factors such as a low protein diet were observed in growing ruminants. In addition, metabolic changes, for example, at the onset of lactation have pronounced effects on gastrointestinal mineral transport processes in some ruminant species. As disturbances of mineral homeostasis do not only increase the risk of the animals to develop other diseases, but are also associated with protein and energy metabolism, further research is needed to improve our knowledge of its complex regulation.
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Guo C, Sun D, Wang X, Mao S. A Combined Metabolomic and Proteomic Study Revealed the Difference in Metabolite and Protein Expression Profiles in Ruminal Tissue From Goats Fed Hay or High-Grain Diets. Front Physiol 2019; 10:66. [PMID: 30800073 PMCID: PMC6375843 DOI: 10.3389/fphys.2019.00066] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/21/2019] [Indexed: 12/23/2022] Open
Abstract
Currently, knowledge about the impact of high-grain (HG) feeding on metabolite and protein expression profiles in ruminal tissue is limited. In this study, a combination of proteomic and metabolomic approaches was applied to evaluate metabolic and proteomic changes of the rumen epithelium in goats fed a hay diet (Hay) or HG diet. At the metabolome level, results from principal component analysis (PCA) and PLS-DA revealed clear differences in the biochemical composition of ruminal tissue of the control (Hay) and the grain-fed groups, demonstrating the evident impact of HG feeding on metabolite profile of ruminal epithelial tissues. As compared with the Hay group, HG feeding increased the levels of eight metabolites and decreased the concentrations of seven metabolites in ruminal epithelial tissues. HG feeding mainly altered starch and sucrose metabolism, purine metabolism, glyoxylate and dicarboxylate metabolism, glycerolipid metabolism, pyruvate metabolism, glycolysis or gluconeogenesis, galactose metabolism, glycine, serine and threonine metabolism, and arginine and proline metabolism in ruminal epithelium. At the proteome level, 35 differentially expressed proteins were found in the rumen epithelium between the Hay and HG groups, with 12 upregulated and 23 downregulated proteins. The downregulated proteins were related to fatty acid metabolism, carbohydrate metabolic processes and nucleoside metabolic processes, while most of upregulated proteins were involved in oxidative stress and detoxification. In general, our findings revealed that HG feeding resulted in differential proteomic and metabolomic profiles in the rumen epithelia of goats, which may contribute to better understanding how rumen epithelium adapt to HG feeding.
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Affiliation(s)
- Changzheng Guo
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, National Experimental Teaching Demonstration Center of Animal Science, National Center for International Research on Animal Gut Nutrition, Joint International Research Laboratory of Animal Health and Food Safety, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Daming Sun
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, National Experimental Teaching Demonstration Center of Animal Science, National Center for International Research on Animal Gut Nutrition, Joint International Research Laboratory of Animal Health and Food Safety, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xinfeng Wang
- College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Shengyong Mao
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, National Experimental Teaching Demonstration Center of Animal Science, National Center for International Research on Animal Gut Nutrition, Joint International Research Laboratory of Animal Health and Food Safety, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
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6
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Caushi D, Martens H. Absorption of bicarbonate in sheep omasum. Res Vet Sci 2018; 118:324-330. [PMID: 29601970 DOI: 10.1016/j.rvsc.2018.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 03/07/2018] [Accepted: 03/09/2018] [Indexed: 10/17/2022]
Abstract
Transport of bicarbonate across the isolated epithelium of sheep omasum was studied in vitro in Ussing chambers in combination with the pH-Stat method. The transport of HCO3- occurred in both directions, but Jms HCO3- was significant larger than Jsm. Reducing the activity of the apical Na/H exchanger by a low mucosal Na concentration caused a significant reduction of Jms HCO3-. Mucosal amiloride or short chain fatty acids (25 mmol l-1 SCFA) numerically decreased Jms HCO3-, but their combination (amiloride + SCFA) caused a significant reduction, which was also observed after addition of the carboanhydrase inhibitor ethoxyzolamide. Concentrations of 5 or 15 mmol·l-1 mucosal ammonia did not change transport rates. The obtained results indicate the importance of an undisturbed cytosolic pH for transcellular HCO3- transport, which is probably mediated by an anion exchanger in both the apical and basolateral membranes. Possible impairment of HCO3- transport appears to be an overlooked factor in the pathogenesis of displacement of the abomasum.
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Affiliation(s)
- Driton Caushi
- Freie Universitaet Berlin, Department of Veterinary Physiology, Oertzenweg 19b, 14163 Berlin, Germany.
| | - Holger Martens
- Freie Universitaet Berlin, Department of Veterinary Physiology, Oertzenweg 19b, 14163 Berlin, Germany.
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7
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Wang B, Wang D, Wu X, Cai J, Liu M, Huang X, Wu J, Liu J, Guan L. Effects of dietary physical or nutritional factors on morphology of rumen papillae and transcriptome changes in lactating dairy cows based on three different forage-based diets. BMC Genomics 2017; 18:353. [PMID: 28477620 PMCID: PMC5420399 DOI: 10.1186/s12864-017-3726-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 04/26/2017] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Rumen epithelial tissue plays an important role in nutrient absorption and rumen health. However, whether forage quality and particle size impact the rumen epithelial morphology is unclear. The current study was conducted to elucidate the effects of forage quality and forage particle size on rumen epithelial morphology and to identify potential underlying molecular mechanisms by analyzing the transcriptome of the rumen epithelium (RE). To achieve these objectives, 18 mid-lactation dairy cows were allocated to three groups (6 cows per group), and were fed with one of three different forage-based diets, alfalfa hay (AH), corn stover (CS), and rice straw (RS) for 14 weeks, respectively. Ruminal volatile fatty acids (VFAs) and epithelial thickness were determined, and RNA-sequencing was conducted to identify the transcriptomic changes of rumen epithelial under different forage-based diets. RESULTS The RS diet exhibited greater particle size but low quality, the AH diet was high nutritional value but small particle size, and CS diet was low quality and small particle size. The ruminal total VFA concentration was greater in AH compared with those in CS or RS. The width of the rumen papillae was greater in RS-fed cows than in cows fed AH or CS. In total, 31, 40, and 28 differentially expressed (DE, fold change > 2, FDR < 0.05) genes were identified via pair-wise comparisons including AH vs. CS, AH vs. RS, and RS vs. CS, respectively. Functional classification analysis of DE genes revealed dynamic changes in ion binding (such as DSG1) between AH and CS, proliferation and apoptotic processes (such as BAG3, HLA-DQA1, and UGT2B17) and complement activation (such as C7) between AH or RS and CS. The expression of HLA-DQA1 was down-regulated in RS compared with AH and CS, and the expression of UGT2B17 was down-regulated in RS compared with CS, with positive (R = 0.94) and negative (R = -0.96) correlation with the width of rumen epithelial papillae (P < 0.05), respectively. CONCLUSION Our results suggest that both nutrients (VFAs) and particle sizes can alter expression of genes involved in cell proliferation/apoptosis process and complement complex. Our results suggest that particle size may be more important in regulating rumen epithelial morphology when animals are fed with low-quality forage diets and the identified DE genes may affect the RE nutrient absorption or morphology of RE. Our findings provide insights into the effects of the dietary particle size in the future management of dairy cow feeding, that when cows were fed with low-quality forage (such as rice straw), smaller particle size may be beneficial for nutrients absorption and milk production.
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Affiliation(s)
- Bing Wang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China.,Current address: Beijing Key Laboratory for Dairy Cow Nutrition, College of Animal Science and Technology, Beijing University of Agriculture, Beijing, 102206, China
| | - Diming Wang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China.,Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Xuehui Wu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China
| | - Jie Cai
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China
| | - Mei Liu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China
| | - Xinbei Huang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China
| | - Jiusheng Wu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jianxin Liu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China. .,MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China.
| | - Leluo Guan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
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8
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Klinger S, Schröder B, Gemmer A, Reimers J, Breves G, Herrmann J, Wilkens MR. Gastrointestinal transport of calcium and glucose in lactating ewes. Physiol Rep 2016; 4:4/11/e12817. [PMID: 27273883 PMCID: PMC4908493 DOI: 10.14814/phy2.12817] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/29/2016] [Indexed: 01/26/2023] Open
Abstract
During lactation, mineral and nutrient requirements increase dramatically, particularly those for Ca and glucose. In contrast to monogastric species, in ruminants, it is rather unclear to which extend this physiological change due to increased demand for milk production is accompanied by functional adaptations of the gastrointestinal tract (GIT). Therefore, we investigated potential modulations of Ca and glucose transport mechanisms in the GIT of lactating and dried‐off sheep. Ussing‐chamber technique was applied to determine the ruminal and jejunal Ca flux rates. In the jejunum, electrophysiological properties in response to glucose were recorded. Jejunal brush‐border membrane vesicles (BBMV) served to characterize glucose uptake via sodium‐linked glucose transporter 1 (SGLT1), and RNA and protein expression levels of Ca and glucose transporting systems were determined. Ruminal Ca flux rate data showed a trend for higher absorption in lactating sheep. In the jejunum, small Ca absorption could only be observed in lactating ewes. From the results, it may be assumed that lactating ewes compensate for the Ca loss by increasing bone mobilization rather than by increasing supply through absorption from the GIT. Presence of SGLT1 in the jejunum of both groups was shown by RNA and protein identification, but glucose uptake into BBMV could only be detected in lactating sheep. This, however, could not be attributed to electrogenic glucose absorption in lactating sheep under Ussing‐chamber conditions, providing evidence that changes in jejunal glucose uptake may include additional factors, that is, posttranslational modifications such as phosphorylation.
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Affiliation(s)
- Stefanie Klinger
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Bernd Schröder
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Anja Gemmer
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Julia Reimers
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Gerhard Breves
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Jens Herrmann
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Mirja R Wilkens
- Department of Physiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
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9
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O'Shea E, Waters SM, Keogh K, Kelly AK, Kenny DA. Examination of the molecular control of ruminal epithelial function in response to dietary restriction and subsequent compensatory growth in cattle. J Anim Sci Biotechnol 2016; 7:53. [PMID: 27651894 PMCID: PMC5025635 DOI: 10.1186/s40104-016-0114-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 08/31/2016] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The objective of this study was to investigate the effect of dietary restriction and subsequent compensatory growth on the relative expression of genes involved in volatile fatty acid transport, metabolism and cell proliferation in ruminal epithelial tissue of beef cattle. Sixty Holstein Friesian bulls (mean liveweight 370 ± 35 kg; mean age 479 ± 15 d) were assigned to one of two groups: (i) restricted feed allowance (RES; n = 30) for 125 d (Period 1) followed by ad libitum access to feed for 55 d (Period 2) or (ii) ad libitum access to feed throughout (ADLIB; n = 30). Target growth rate for RES was 0.6 kg/d during Period 1. At the end of each dietary period, 15 animals from each treatment group were slaughtered and ruminal epithelial tissue and liquid digesta harvested from the ventral sac of the rumen. Real-time qPCR was used to quantify mRNA transcripts of 26 genes associated with ruminal epithelial function. Volatile fatty acid analysis of rumen fluid from individual animals was conducted using gas chromatography. RESULTS Diet × period interactions were evident for genes involved in ketogenesis (BDH2, P = 0.017), pyruvate metabolism (LDHa, P = 0.048; PDHA1, P = 0.015) and cellular transport and structure (DSG1, P = 0.019; CACT, P = 0.027). Ruminal concentrations of propionic acid (P = 0.018) and n-valeric acid (P = 0.029) were lower in RES animals, compared with ADLIB, throughout the experiment. There was also a strong tendency (P = 0.064) toward a diet × period interaction for n-butyric with higher concentrations in RES animals, compared with ADLIB, during Period 1. CONCLUSIONS These data suggest that following nutrient restriction, the structural integrity of the rumen wall is compromised and there is upregulation of genes involved in the production of ketone bodies and breakdown of pyruvate for cellular energy. These results provide an insight into the potential molecular mechanisms regulating ruminal epithelial absorptive metabolism and growth following nutrient restriction and subsequent compensatory growth.
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Affiliation(s)
- Emma O'Shea
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, 4 Ireland ; Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc Grange, Dunsany, Co. Meath, Ireland ; UCD Earth Institute, University College Dublin, Belfield, Dublin, 4 Ireland
| | - Sinéad M Waters
- Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc Grange, Dunsany, Co. Meath, Ireland
| | - Kate Keogh
- Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc Grange, Dunsany, Co. Meath, Ireland
| | - Alan K Kelly
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, 4 Ireland
| | - David A Kenny
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, 4 Ireland ; Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc Grange, Dunsany, Co. Meath, Ireland
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10
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Gui H, Shen Z. Concentrate diet modulation of ruminal genes involved in cell proliferation and apoptosis is related to combined effects of short-chain fatty acid and pH in rumen of goats. J Dairy Sci 2016; 99:6627-6638. [PMID: 27236768 DOI: 10.3168/jds.2015-10446] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 03/28/2016] [Indexed: 01/20/2023]
Abstract
Short-chain fatty acids (SCFA) regulate cell proliferation and cell apoptosis in gastrointestinal tissue in vitro and in vivo. We have tested the hypothesis that a medium-concentrate intake induces mRNA abundance alterations of genes involved in cell proliferation and cell apoptosis in the rumen epithelium of goats, and that these changes in mRNA abundance are related to ruminal SCFA concentration and ruminal pH. Goats (n=16) were randomly allocated to 2 groups and fed either a low-concentrate (LC) diet (10% concentrate; n=8) or a medium-concentrate (MC) diet (35% concentrate; n=8) in 2 equal portions daily. The individually housed goats were fed separately with their respective diet for 3wk and were slaughtered 6h after the morning feed on d 22. In vivo, goats receiving the MC treatment exhibited a greater ruminal SCFA concentration (73.7mM) compared with those receiving the LC treatment (53.2mM), and the pH decreased from 6.9 to 6.5. The expression of proliferative genes of cyclin A, cyclin B1, cyclin D1, cyclin E1, CDK1, CDK2, CDK4, and CDK6 mRNA in the MC group was enhanced. The gene expression of apoptosis genes (caspase 3, caspase 8, caspase 9, p53, and Bax) was significantly higher, and the ratio of Bcl-2 to Bax (Bcl-2/Bax) expression was lower in the MC group than in the LC group. The same trend was observed in the population of apoptotic cells analyzed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The cell density in the stratum germinativum of the MC group was significantly increased compared with that in the LC group. During primary culture of rumen epithelial cells, SCFA or pH treatment alone of the culture medium had significant effects on the expression of most of the genes tested in the present study. Furthermore, SCFA and pH exerted combined effects on the expression of cyclin A, cyclin B1, cyclin E1, CDK6, p53, Bcl-2, and Bcl-2/Bax. Thus, the MC diet induces alteration of gene expression of the genes that regulate both cell proliferation and apoptosis. These genes are regulated by combined effect of ruminal SCFA and ruminal pH.
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Affiliation(s)
- Hongbing Gui
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agriculture University, Nanjing, China, 210095
| | - Zanming Shen
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agriculture University, Nanjing, China, 210095.
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11
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Lu Z, Yao L, Jiang Z, Aschenbach JR, Martens H, Shen Z. Acidic pH and short-chain fatty acids activate Na+ transport but differentially modulate expression of Na+/H+ exchanger isoforms 1, 2, and 3 in omasal epithelium. J Dairy Sci 2015; 99:733-45. [PMID: 26547645 DOI: 10.3168/jds.2015-9605] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 09/20/2015] [Indexed: 01/18/2023]
Abstract
Low sodium content in feed and large amounts of salivary sodium secretion are essential requirements to efficient sodium reabsorption in the dairy cow. It is already known that Na(+)/H(+) exchange (NHE) of the ruminal epithelium plays a key role in Na(+) absorption, and its function is influenced by the presence of short-chain fatty acids (SCFA) and mucosal pH. By contrast, the functional role and regulation of NHE in omasal epithelium have not been completely understood. In the present study, we used model studies in small ruminants (sheep and goats) to investigate NHE-mediated Na(+) transport and the effects of pH and SCFA on NHE activity in omasal epithelium and on the expression of NHE isoform in omasal epithelial cells. Conventional Ussing chamber technique, primary cell culture, quantitative PCR, and Western blot were used. In native omasal epithelium of sheep, the Na(+) transport was electroneutral, and it was inhibited by the specific NHE3 inhibitor 3-[2-(3-guanidino-2-methyl-3-oxo-propenyl)-5-methyl-phenyl]-N-isopropylidene-2-methyl-acrylamide dihydrochloride, which decreased mucosal-to-serosal, serosal-to-mucosal, and net flux rates of Na(+) by 80% each. The application of low mucosal pH (6.4 or 5.8) in the presence of SCFA activated the Na(+) transport across omasal epithelium of sheep compared with that at pH 7.4. In cultured omasal epithelial cells of goats, mRNA and protein of NHE1, NHE2, and NHE3 were detected. The application of SCFA increased NHE1 mRNA and protein expression, which was most prominent when the culture medium pH decreased from 7.4 to 6.8. At variance, the mRNA and protein expression of NHE2 and NHE3 were decreased with low pH and SCFA, which was contrary to the published data from ruminal epithelial studies. In conclusion, this paper shows that (1) NHE1, NHE2, and NHE3 are expressed in omasal epithelium; (2) NHE3 mediates the major portion of transepithelial Na(+) transport in omasal epithelium; and (3) SCFA and acidic pH acutely activate Na(+) transport but suppress the expression of NHE2 and NHE3 in the longer term. By contrast, the expression of NHE1 is increased by SCFA and acidic pH, indicating a prominent role for NHE1 in the regulation of intracellular pH of omasal epithelium. Our results suggest a regulatable Na(+) absorption in ruminal and omasal epithelium. It is of benefit for intracellular pH homeostasis and highly relevant to dairy cows fed on high-concentrate diets.
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Affiliation(s)
- Zhongyan Lu
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, China; Institute of Veterinary Physiology, Free University of Berlin, D-14163 Berlin, Germany
| | - Lei Yao
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhengqian Jiang
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Jörg R Aschenbach
- Institute of Veterinary Physiology, Free University of Berlin, D-14163 Berlin, Germany
| | - Holger Martens
- Institute of Veterinary Physiology, Free University of Berlin, D-14163 Berlin, Germany
| | - Zanming Shen
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, China.
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12
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Zhao H, Lu J, Huang Z, Yan L, Holger M, Shen Z. High concentrate:forage ratio diet inhibiting omasal epithelium growth is associated with decreased cyclin D1 and CDK4 expression in growing goats. Anim Sci J 2014; 85:660-70. [PMID: 24735377 DOI: 10.1111/asj.12194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 12/13/2013] [Indexed: 01/01/2023]
Abstract
The hypothesis that different concentrate : forage ratio diets alter omasal epithelium proliferation of growing goats via cyclins and regulation of the cell cycle was tested. Growing goats were fed with a high concentrate (HC, n = 8) or a low concentrate (LC, n = 8) diet for 42 days. The concentrate : forage ratio was 40:60 in the HC group and 0:100 in the LC group. In the HC group, the relative weight and DNA content of the omasal epithelium were lower, but the protein : DNA ratio was higher. Flow cytometry revealed that HC omasal cell numbers were smaller in S- and G2 /M-phases of the cell cycle and higher in the G0 /G1 -phases and were accompanied by reduced expression of cyclin D1 and CDK4 mRNA and protein. These data are consistent with morphologic observations in the HC that cell density decreased in the stratum spinosum (SS) plus stratum granulosum (SG) and stratum basale, and that cell density was lower in the SS plus SG. Thus, high-concentrate : forage ratio diet retards omasal epithelial growth by slowing the G1 to S phase transition of the cell cycle and is associated with decreased cyclin D1 and CDK4 expression in growing goats.
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Affiliation(s)
- Huaibao Zhao
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing, China
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13
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Albornoz RI, Aschenbach JR, Barreda DR, Penner GB. Moderate decreases in the forage-to-concentrate ratio before feed restriction and increases thereafter independently improve the recovery from a feed restriction insult in beef cattle. J Anim Sci 2013; 91:4739-49. [PMID: 23942712 DOI: 10.2527/jas.2012-6224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The objective of this study was to determine if the forage-to-concentrate ratio (F:C) of diets fed prior to and during (PRE) feed restriction (FR) and diets fed post-FR (POST) affect the recovery for DMI, ruminal fermentation, and short-chain fatty acid (SCFA) absorption following FR. Twenty ovariectomized and ruminally cannulated Angus × Hereford heifers were used in this study and were fed (ad libitum) either a high forage (HF; F:C = 92:8) or a moderate forage (MF; F:C = 60:40) diet for 19 d. Heifers were then exposed to a 5-d FR period where feed was restricted to 25% of ad libitum intake relative to that measured during the previous 5 d. After FR, heifers were provided feed ad libitum with one half of the HF and MF heifers receiving the HF or MF diet during the 3-wk recovery period (REC1, REC2, and REC3). This resulted in 4 treatment combinations separated over time (PRE-POST): HF-HF, HF-MF, MF-HF, and MF-MF. The PRE × POST interaction was not significant for any of the measured variables, and the PRE × POST × period interaction was only significant for the molar proportion of ruminal butyrate. For heifers fed HF PRE, DMI increased from REC1 to REC3 whereas DMI did not differ among periods for heifers fed MF PRE (PRE × period, P = 0.045). The duration that pH < 5.5 (PRE × POST; P = 0.003) was numerically greater during REC1 for heifers fed HF than MF PRE (191 vs. 98 min/d), with duration decreasing from REC1 to REC2 for heifers fed HF PRE. Total ruminal SCFA concentration and absorption rate were not affected by the diet fed PRE (P > 0.05) or period (P > 0.05). For heifers fed MF POST, DMI increased from REC1 to REC3 whereas DMI did not differ among POST periods for heifers fed HF POST (POST × period, P = 0.033). The duration that ruminal pH was <5.5 was greater for heifers fed MF than HF POST (274.9 vs. 14.1 min/d; POST × period, P < 0.001) with MF heifers decreasing duration from REC1 to REC2 whereas duration did not differ among periods for HF. Ruminal SCFA concentration and rate of absorption were not affected (P > 0.05) by diet fed POST. It is concluded that feeding a MF diet prior to and during FR improves the recovery response for DMI. Irrespective of the prefeeding, however, a HF diet is beneficial in the POST-restriction period because it most effectively alleviated ruminal pH reduction and hastened DMI recovery.
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Affiliation(s)
- R I Albornoz
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada
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14
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Plöger S, Stumpff F, Penner GB, Schulzke JD, Gäbel G, Martens H, Shen Z, Günzel D, Aschenbach JR. Microbial butyrate and its role for barrier function in the gastrointestinal tract. Ann N Y Acad Sci 2012; 1258:52-9. [PMID: 22731715 DOI: 10.1111/j.1749-6632.2012.06553.x] [Citation(s) in RCA: 291] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Butyrate production in the large intestine and ruminant forestomach depends on bacterial butyryl-CoA/acetate-CoA transferase activity and is highest when fermentable fiber and nonstructural carbohydrates are balanced. Gastrointestinal epithelia seem to use butyrate and butyrate-induced endocrine signals to adapt proliferation, apoptosis, and differentiation to the growth of the bacterial community. Butyrate has a potential clinical application in the treatment of inflammatory bowel disease (IBD; ulcerative colitis). Via inhibited release of tumor necrosis factor α and interleukin 13 and inhibition of histone deacetylase, butyrate may contribute to the restoration of the tight junction barrier in IBD by affecting the expression of claudin-2, occludin, cingulin, and zonula occludens poteins (ZO-1, ZO-2). Further evaluation of the molecular events that link butyrate to an improved tight junction structure will allow for the elucidation of the cofactors affecting the reliability of butyrate as a clinical treatment tool.
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Affiliation(s)
- Svenja Plöger
- Institute of Veterinary Physiology, Free University of Berlin, Berlin, Germany
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15
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Wilson DJ, Mutsvangwa T, Penner GB. Supplemental butyrate does not enhance the absorptive or barrier functions of the isolated ovine ruminal epithelia. J Anim Sci 2012; 90:3153-61. [PMID: 22585785 DOI: 10.2527/jas.2011-4315] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our objective was to determine if increasing the ruminal butyrate concentration would improve the selective permeability of ruminal epithelia. Suffolk wether lambs (n = 18) with an initial BW of 47.4 ±1.4 kg were housed in individual pens (1.5 × 1.5 m) with rubber mats on the floor. Lambs were blocked by initial BW into 6 blocks and, within block, were randomly assigned to either the control (CON) or 1 of 2 butyrate supplementation amounts (i.e., 1.25% or 2.50% butyrate as a proportion of DMI). With the exception of butyrate supplementation, all lambs were fed a common diet (90% concentrate and 10% barley silage). After a 14-d feeding period, lambs were killed, and ruminal epithelia from the ventral sac were mounted in Ussing chambers. To facilitate the Ussing chamber measurements, only 1 lamb was killed on an individual day. Thus, the starting date was staggered so that all lambs were exposed to the same experimental protocol. In Ussing chambers, epithelia were incubated using separate mucosal (pH 6.2) and serosal (pH 7.4) bathing solutions. Then 1-14C-butyrate (74 kBq/10 mL) was added to the mucosal side and was used to measure the mucosal-to-serosal flux (J(ms-butyrate)) in 2 consecutive 60-min flux periods with simultaneous measurement of transepithelial conductance (G(t)). During the first (challenge) flux period, the mucosal buffer solution was either acidified to pH 5.2 (ACID) or used as a control (pH 6.2; SHAM). Buffer solutions bathing the epithelia were replaced before the second flux period (recovery). Total ruminal short-chain fatty acid and butyrate concentrations were greater (P = 0.001) in lambs fed 2.50% compared with those fed 0% or 1.25% butyrate. The J(ms-butyrate) was less for lambs fed 1.25% and 2.50% butyrate [3.00 and 3.12 μmol/(cm2·h), respectively] than for CON [3.91 μmol/(cm2· h)]. However, no difference (P = 0.13)was observed for G(t). An ex vivo treatment × flux period interaction was detected (P = 0.003) for J(ms-butyrate), where no differences were present between ACID and SHAM during the challenge period, but the Jms-butyrate was less for ACID than for SHAM during recovery. These results indicate that large increases in the ruminal butyrate concentration decrease the selective permeability of the isolated ruminal epithelia.
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Affiliation(s)
- D J Wilson
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon S7N 5A8, Canada
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16
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Shen Z, Martens H, Schweigel-Röntgen M. Na+transport across rumen epithelium of hay-fed sheep is acutely stimulated by the peptide IGF-1in vitro. Exp Physiol 2012; 97:497-505. [DOI: 10.1113/expphysiol.2011.061580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Martens H, Rabbani I, Shen Z, Stumpff F, Deiner C. Changes in rumen absorption processes during transition. Anim Feed Sci Technol 2012. [DOI: 10.1016/j.anifeedsci.2011.12.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Yang W, Shen Z, Martens H. An energy-rich diet enhances expression of Na+/H+ exchanger isoform 1 and 3 messenger RNA in rumen epithelium of goat1. J Anim Sci 2012; 90:307-17. [DOI: 10.2527/jas.2011-3854] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- W. Yang
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Z. Shen
- Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - H. Martens
- Institute of Veterinary Physiology, Free University Berlin, D-14163 Berlin, Germany
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19
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Taniguchi M, Penner GB, Beauchemin KA, Oba M, Guan LL. Comparative analysis of gene expression profiles in ruminal tissue from Holstein dairy cows fed high or low concentrate diets. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2010; 5:274-9. [DOI: 10.1016/j.cbd.2010.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 07/23/2010] [Accepted: 07/25/2010] [Indexed: 12/14/2022]
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20
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Penner GB, Taniguchi M, Guan LL, Beauchemin KA, Oba M. Effect of dietary forage to concentrate ratio on volatile fatty acid absorption and the expression of genes related to volatile fatty acid absorption and metabolism in ruminal tissue. J Dairy Sci 2009; 92:2767-81. [PMID: 19448011 DOI: 10.3168/jds.2008-1716] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objective of the study was to investigate the fractional rate of volatile fatty acid (VFA) absorption and the expression of genes encoding for transporters and enzymes involved in the absorption and metabolism of VFA in ruminal tissue when cattle were fed high or low concentrate diets. Twelve ruminally cannulated Holstein cows were used in a randomized complete block design. The low concentrate (LC) and high concentrate (HC) diets contained 8 and 64% dietary concentrate (dry matter basis), respectively. Cows were fed their respective diet for at least 28 d, following which data and samples were collected over 6 d. Ruminal pH was measured continuously for 72 h, and the in vivo VFA absorption and passage rates were measured using Co-EDTA and n-valeric acid as markers. Ruminal tissue was collected postslaughter from the ventral sac of the rumen, and gene expression was evaluated using quantitative real-time PCR. Dry matter intake was not affected by treatment, averaging 14.9 kg/d, but cows fed HC had lower mean ruminal pH (6.03 vs. 6.48), and a greater duration (376 vs. 10 min/d) that ruminal pH was <5.8. Ruminal VFA concentration was 24 mM higher for cows fed HC compared with LC; however, the fractional rate of VFA absorption and passage from the rumen was not affected by dietary treatment, averaging 23.4 and 9.6%/h, respectively. The expression of genes encoding for enzymes involved in VFA activation and ketogenesis were not affected by treatment. Cows fed HC tended to have a relative abundance of pyruvate dehydrogenase lipoamide alpha 1 mRNA transcripts that was 1.4 times lower than that of cows fed LC, but other enzymes involved in pyruvate metabolism or regulation of the citric acid cycle were not affected. Collectively, these results suggest that the dietary forage to concentrate ratio does not affect the fractional rate of VFA absorption in vivo, but potentially alters energy metabolism in ruminal tissue.
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Affiliation(s)
- G B Penner
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, T6G 2P5, Canada
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21
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Etschmann B, Suplie A, Martens H. Change of ruminal sodium transport in sheep during dietary adaptation. Arch Anim Nutr 2009; 63:26-38. [PMID: 19271549 DOI: 10.1080/17450390802506885] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Rumen adaptation plays an important role in the productive cycle of dairy cattle. In this study, the time course of functional rumen epithelium adaptation after a change from hay feeding (ad libitum) to a mixed hay/concentrate diet was monitored by measuring Na+ transport rates in Ussing chamber experiments. A total of 18 sheep were subjected to different periods of mixed hay/concentrate feeding ranging from 0 weeks (control; hay ad libitum) to 12 weeks (800 g hay plus 800 g concentrate per day in two equal portions). For each animal, the net absorption of sodium was measured following the mixed hay/concentrate feeding period. Net Na transport, Jnet, significantly rose from 2.15 +/- 0.43 (control) to 3.73 +/- 1.02 microeq x cm(-2) x h(-1) after one week of mixed hay/ concentrate diet, reached peak levels of 4.55 +/- 0.50 microEq x cm(-2) x h(-1) after four weeks and levelled out at 3.92 +/- 0.36 microeq x cm(-2) x h(-1) after 12 weeks of mixed feeding. Thus, 73% of functional adaptation occurred during the first week after diet change. This is in apparent contrast to findings that morphological adaptation takes approximately six weeks to reach peak levels. Hence, early functional adaptation to a mixed hay/concentrate diet is characterised by enhanced Na absorption rates per epithelial cell. Absorption rates are likely to be further enhanced by proliferative effects on the rumen epithelium (number and size of papillae) when concentrate diets are fed over longer periods of time. Early functional adaptation without surface area enlargement of the rumen epithelium appears to be the first step in coping with altered fermentation rates following diet change.
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Affiliation(s)
- Benjamin Etschmann
- Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Germany
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22
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Lodemann U, Martens H. Effects of diet and osmotic pressure on Na+transport and tissue conductance of sheep isolated rumen epithelium. Exp Physiol 2006; 91:539-50. [PMID: 16452124 DOI: 10.1113/expphysiol.2005.032078] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The intention of this study was to determine the effects of mucosal osmotic pressure on transport and barrier functions of the rumen epithelium of sheep, which were fed various diets: hay ad libitum, or 600, 1200 or 1800 g day(-1) of a supplemented diet plus hay ad libitum. The experiments were conducted by using the conventional Ussing chamber technique. Mucosal osmolarity was adjusted to 300 (control), 375 or 450 mosmol l(-1). Feeding of a supplemented diet led to a significant increase of mucosal to serosal Na+ transport and net Na+ transport, probably because of an increase of apical Na+-H+ exchange activity. An increase in mucosal osmotic pressure: (a) reduced net Na+ transport in all feeding groups, the remaining net Na+ transport being higher in tissues of sheep fed a supplemented diet; (b) increased transepithelial tissue conductance, this rise being smallest with a high intake of the supplemented diet; and (c) enhanced the serosal to mucosal Na+ transport in tissues of hay-fed sheep and sheep fed with 600 g day(-1) of the supplemented diet, while higher intakes of the supplemented diet (1200 and 1800 g) did not produce any effect. All these changes indicate a diet-dependent adaptation to luminal hypertonicity.
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Affiliation(s)
- Ulrike Lodemann
- Department of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, Germany.
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