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Kong F, Liu Y, Wang S, Zhang Y, Wang W, Yang H, Lu N, Li S. Nutrient Digestibility, Microbial Fermentation, and Response in Bacterial Composition to Methionine Dipeptide: An In Vitro Study. BIOLOGY 2022; 11:biology11010093. [PMID: 35053091 PMCID: PMC8772947 DOI: 10.3390/biology11010093] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 11/20/2022]
Abstract
Simple Summary The rumen microbiota plays an important role in maintaining microbiota homeostasis and promoting milk production synthesis through utilizing amino acids and non-protein nitrogen. Furthermore, various nitrogen sources have shown distinct effects on microbial growth rates. The methionine dipeptide (MD) is a bioactive peptide consisting of two methionine (Met) residues linked by a peptide bond. Although the role of MD in milk protein synthesis is established, little is known about its role in bacterial fermentation. The present study demonstrates that the various nitrogen sources could reshape microbiota differently, and MD could be more efficient than free Met in the rumen to support acetate producer growth. Our study provides some new insights into the relationship between ruminal microbiota of dairy cows and small peptides and points to potential strategies to effectively enhance the health condition and digestion ability of dairy cows. Abstract It is well known that the methionine dipeptide (MD) could enhance the dairy cows milking performance. However, there is still a knowledge gap of the effects of MD on the rumen fermentation characteristics, microbiota composition, and digestibility. This experiment was conducted to determine the effect of different nitrogen sources with a total mixed ration on in vitro nutrient digestibility, fermentation characteristics, and bacterial composition. The treatments included 5 mg urea (UR), 25.08 mg methionine (Met), 23.57 mg MD, and no additive (CON) in fermentation culture medium composed of buffer solution, filtrated Holstein dairy cow rumen fluid, and substrate (1 g total mixed ration). Nutrient digestibility was measured after 24 h and 48 h fermentation, and fermentation parameters and microbial composition were measured after 48 h fermentation. Digestibility of dry matter, crude protein, neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the MD group at 48 h were significantly higher than in the CON and UR groups. The total volatile fatty acid concentration was higher in the MD group than in the other groups. In addition, 16S rRNA microbial sequencing results showed MD significantly improved the relative abundances of Succinivibrio, Anaerotruncus, and Treponema_2, whereas there was no significant difference between Met and UR groups. Spearman’s correlation analysis showed the relative abundance of Succinivibrio and Anaerotruncus were positively correlated with gas production, NDF digestibility, ADF digestibility, and acetate, propionate, butyrate, and total volatile fatty acid concentrations. Overall, our results suggested that the microbiota in the fermentation system could be affected by additional nitrogen supplementation and MD could effectively enhance the nutrient utilization in dairy cows.
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Affiliation(s)
- Fanlin Kong
- The State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (F.K.); (S.W.); (W.W.); (H.Y.)
| | - Yanfang Liu
- Beijing Jingwa Agricultural Science & Technology Innovation Center, Beijing 100193, China;
| | - Shuo Wang
- The State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (F.K.); (S.W.); (W.W.); (H.Y.)
| | - Yijia Zhang
- Laboratory of Anatomy of Domestic Animals, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
| | - Wei Wang
- The State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (F.K.); (S.W.); (W.W.); (H.Y.)
| | - Hongjian Yang
- The State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (F.K.); (S.W.); (W.W.); (H.Y.)
| | - Na Lu
- Beijing Jingwa Agricultural Science & Technology Innovation Center, Beijing 100193, China;
- Correspondence: (N.L.); (S.L.); Tel.: +86-10-62731254 (S.L.)
| | - Shengli Li
- The State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (F.K.); (S.W.); (W.W.); (H.Y.)
- Correspondence: (N.L.); (S.L.); Tel.: +86-10-62731254 (S.L.)
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Regulation of Milk Protein Synthesis by Free and Peptide-Bound Amino Acids in Dairy Cows. BIOLOGY 2021; 10:biology10101044. [PMID: 34681143 PMCID: PMC8533557 DOI: 10.3390/biology10101044] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 11/17/2022]
Abstract
Milk protein (MP) synthesis in the mammary gland of dairy cows is a complex biological process. As the substrates for protein synthesis, amino acids (AAs) are the most important nutrients for milk synthesis. Free AAs (FAAs) are the main precursors of MP synthesis, and their supplies are supplemented by peptide-bound AAs (PBAAs) in the blood. Utilization of AAs in the mammary gland of dairy cows has attracted the great interest of researchers because of the goal of increasing MP yield. Supplying sufficient and balanced AAs is critical to improve MP concentration and yield in dairy cows. Great progress has been made in understanding limiting AAs and their requirements for MP synthesis in dairy cows. This review focuses on the effects of FAA and PBAA supply on MP synthesis and their underlying mechanisms. Advances in our knowledge in the field can help us to develop more accurate models to predict dietary protein requirements for dairy cows MP synthesis, which will ultimately improve the nitrogen utilization efficiency and lactation performance of dairy cows.
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Kalyesubula M, Casey TM, Reicher N, Sabastian C, Wein Y, Bar Shira E, Hoang N, George UZ, Shamay A, Plaut K, Mabjeesh SJ. Physiological state and photoperiod exposures differentially influence circadian rhythms of body temperature and prolactin and relate to changes in mammary PER1 expression in late pregnant and early lactation dairy goats. Small Rumin Res 2021. [DOI: 10.1016/j.smallrumres.2021.106394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Effects of Different Methionine Sources on Methionine Metabolism in the IPEC-J2 Cells. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5464906. [PMID: 31380429 PMCID: PMC6662248 DOI: 10.1155/2019/5464906] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/11/2019] [Indexed: 01/01/2023]
Abstract
As one of the essential amino acids, methionine (Met) plays an important role in biological events such as methylation and antioxidant properties besides its function in protein synthesis. Different Met sources have been used in animal production, but their effects on Met metabolic pathways are not well understood. In the present study, we investigated the effects of different Met sources (L-Met, DL-Met, DL-2-hydroxy-4-(methylthio)butanoic acid (DL-HMTBA), and DL-methionyl-DL-methionine (DL-MM)) on the metabolism of Met in small intestinal porcine epithelial cell line (IPEC-J2) and the contents of extracellular Met sources. The results showed that concentrations of intracellular Met, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and the ratio of SAM to SAH in the DL-HMTBA group were significantly lower than that in other Met source groups, while the content of 5-methyltetrahydrofolate (5-MTHF) was significantly higher. Moreover, the mRNA levels of MAT2A, AHcy, CBS, MTHFR, and MTR in the DL-HMTBA group were significantly higher than those in other Met source groups. Further study showed that the total content of extracellular Met sources was highest in the DL-HMTBA group, followed by DL-MM group, followed by L-Met and DL-Met groups. These results demonstrated that DL-HMTBA mainly affects the transmethylation and remethylation of Met and it can promote the trans-sulfur metabolism of Met when compared with other Met sources. In addition, most DL-HMTBA and a small amount of DL-MM can escape the intestinal first-pass metabolism and then provide more extracellular Met sources than L-Met and DL-Met. Therefore, this study can provide a theoretical basis for the selection of Met sources in livestock.
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Xu Q, Hong H, Wu J, Yan X. Bioavailability of bioactive peptides derived from food proteins across the intestinal epithelial membrane: A review. Trends Food Sci Technol 2019. [DOI: 10.1016/j.tifs.2019.02.050] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Krogh U, Oksbjerg N, Storm AC, Feyera T, Theil PK. Mammary nutrient uptake in multiparous sows fed supplementary arginine during gestation and lactation. J Anim Sci 2018; 95:2517-2532. [PMID: 28727031 DOI: 10.2527/jas.2016.1291] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Arginine is the precursor for the synthesis of nitric oxide and may increase mammary plasma flow (MPF), which may in turn increase mammary nutrient uptake. Quantifying mammary nutrient uptake improves our understanding of mammary nutrient metabolism and may potentially allow identification of limiting nutrients for colostrum and milk production. Thus, the objectives of the present study were 1) to study the impact of 25 g/d of crystalline Arg (ARG) on MPF and uptake of nutrients by the mammary glands compared with an isonitrogenous supply of Ala (51 g/d; control [CON]) fed to a total of 8 sows from d 30 of gestation until weaning on d 28 of lactation and 2) to quantify mammary nutrient uptake in late gestation and in early and at peak lactation. Sows were surgically fitted with indwelling catheters on d 76 ± 2 SEM of gestation. -amino hippuric acid (AH) was infused (3.0 mmol/h) in the infusion catheter inserted in the mammary vein, initiated 1 h before the first blood sample at -10, -3, 3, and 17 d in milk (DIM). Blood samples were simultaneously drawn from catheters inserted in the femoral artery and the mammary vein, and the samples were collected in hourly intervals from 0.5 h before to 6.5 h after feeding. Sow milk production was assessed at 3 and 17 DIM. Arterial plasma concentrations of Arg and Ala were increased in ARG and CON sows, respectively ( < 0.01), whereas we did not succeed in detecting a greater MPF in ARG sows ( = 0.30). Arterial-venous differences ( = 0.03) and net mammary flux ( = 0.01) of Ala were increased in CON sows, while the net flux of most other metabolites ( > 0.05) was unaffected by treatment. The mammary extraction of all essential AA was below 13% in late gestation. The average mammary extraction of essential AA at peak lactation was greatest for Leu (51%), while the preprandial extraction was greatest for Lys (57%). The mammary carbon balance (input-output) was negative (-39 ± 12 mol C/d) in early lactation but almost balanced at peak lactation (-13 ± 14 mol C/d), suggesting that mammary fat depots contributed to milk synthesis. In conclusion, we failed to observe an increased MPF and mammary uptake of AA and energy metabolites in ARG-supplemented sows. The mammary extraction rate of essential AA indicated that AA were not limiting for the mammary glands in late gestation, while Lys and Leu appeared to be the 2 most limiting essential AA for milk production at peak lactation.
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Krogh U, Storm AC, Theil PK. Technical note: Measurement of mammary plasma flow in sows by downstream dilution of mammary vein infused -aminohippuric acid. J Anim Sci 2017; 94:5122-5128. [PMID: 28046185 DOI: 10.2527/jas.2016-0853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The objectives of the present study were to design a method to estimate mammary plasma flow (MPF) in lactating sows using downstream dilution of -aminohippuric acid (AH) and to compare these estimates with MPF estimates based on specific AA as internal markers (MPF-AA). A permanent indwelling catheter was surgically implanted in the femoral artery, and another 2 were inserted in the right cranial mammary vein of 8 second- and third-parity sows on d 76 ± 2 SEM of gestation. On the 3rd and 17th days in milk, arterial and venous blood samples were drawn in hourly intervals from 0.5 h before until 6.5 h after feeding. The MPF in the right cranial mammary vein was measured by downstream dilution of infused AH (3.0 mmol/h). Total MPF-AH was calculated assuming that the measured flow constituted the flow from 5 out of 14 suckled glands on the basis of the anatomical structure of the mammary vascular system. Total MPF-AA was estimated on the basis of the output of the specific AA marker in milk and the arteriovenous differences of the marker as free AA in plasma, assuming a direct transfer of AA from plasma to milk protein. Total MPF-AH was 6,860 L/d in early lactation and increased to 8,953 L/d at peak lactation ( = 0.003). In early lactation, MPF-AA estimates were greater or tended to be greater (132% to 175%; < 0.10) than MPF-AH estimates for all internal markers, except Met (119%). Moreover, MPF-AH was correlated with MPF-AA only for MET as an internal marker ( = 0.74; = 0.03) in early lactation. In contrast, MPF-AH and MPF-AA estimates did not differ and were well correlated at peak lactation with the strongest correlation observed when Met ( = 0.84; = 0.009) and Phe + Tyr ( = 0.82; = 0.01) were used as the internal AA markers. Litter gain increased from d 3 to 17 of lactation (2.13 vs. 3.46 g/d; = 0.001) and was correlated with MPF-AH during lactation ( = 0.74; < 0.001), whereas no correlation between litter gain and MPF-AA was observed ( > 0.10). These results suggest that downstream dilution of infused AH and the AA methods are applicable methods to estimate MPF at peak lactation. The reason for the observed discrepancy in early lactation between MPF- AH and MPF-AA is not obvious but might be related to the rapid metabolic changes observed in early lactation. In conclusion, MPF measured by downstream dilution of mammary infused AH was higher at peak compared to early lactation, which the internal AA marker approach failed to show.
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Wang B, Sun H, Xu N, Zhu K, Liu J. Amino acid utilization of lactating dairy cows when diets are changed from an alfalfa-based diet to cereal straw-based diets. Anim Feed Sci Technol 2016. [DOI: 10.1016/j.anifeedsci.2016.04.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Yang JX, Wang CH, Xu QB, Zhao FQ, Liu JX, Liu HY. Methionyl-Methionine Promotes α-s1 Casein Synthesis in Bovine Mammary Gland Explants by Enhancing Intracellular Substrate Availability and Activating JAK2-STAT5 and mTOR-Mediated Signaling Pathways. J Nutr 2015; 145:1748-53. [PMID: 26108540 DOI: 10.3945/jn.114.208330] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 05/29/2015] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Interest is increasing in the role of peptide-bound amino acids (AAs) in milk protein synthesis because studies have found that the uptake of some essential AAs by the mammary gland cannot meet the requirements for milk protein synthesis. Although the role of dipeptides in milk protein synthesis is clearly established, little is known about the underlying mechanisms. OBJECTIVE The objective of this study was to determine whether small peptides can be taken up intact by the peptide transporters in mammary tissue explants and the underlying mechanisms of the effects of methionyl-methionine (Met-Met) supplementation on milk protein synthesis. METHODS Mammary tissue explants were cultured in conditional medium and then treated with different concentrations of Met-Met that replaced 0%, 5%, 10%, 15%, 20%, and 25% of free Met for another 24 h. In some experiments, explants were cultured with an optimal dose of Met-Met with or without the inhibitors of peptide transporter 2 [PepT2; diethylpyrocarbonate (DEPC), 0.1 mmol/L] and aminopeptidase N (APN; bestatin, 20 μmol/L) for 24 h. RESULTS The substitutions of 15% free Met with Met-Met significantly promoted α-s1 casein (αs1-CN) expression in the mammary explants (P < 0.05). The inhibition of the PepT2 by DEPC or APN by bestatin significantly decreased the Met-Met-stimulated increase of αs1-CN expression (P < 0.05). Compared with the control group (0% Met-Met), absorption of Val, Met, Leu, Phe, Lys, and His was improved, and mRNA abundance of the neutral and basic AA transporter was increased in the 15% Met-Met group (P < 0.05). In addition, the mRNA abundance of the mammalian target of rapamycin (mTOR), p70 ribosomal S6 kinase 1 gene, eukaryotic initiation factor 4E binding protein 1 gene , Janus kinase 2 (JAK2), and signal transducer and activator of transcription 5 (STAT5) was increased in the 15% Met-Met-treated group (P < 0.05). CONCLUSION Met-Met promoted αs1-CN synthesis in cultured bovine mammary gland explants, and this stimulation may be mediated by enhanced intracellular substrate availability and by activating JAK2-STAT5 and mTOR signaling pathways.
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Affiliation(s)
- Jian-Xiang Yang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China; and
| | - Cai-Hong Wang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China; and
| | - Qing-Biao Xu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China; and
| | - Feng-Qi Zhao
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China; and Laboratory of Lactation and Metabolic Physiology, Department of Animal Science, University of Vermont, Burlington, VT
| | - Jian-Xin Liu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China; and
| | - Hong-Yun Liu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, China; and
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Ding W, Guo X, Ataku K. Characterization of peptides in ensiled alfalfa treated with different chemical additives. Anim Sci J 2013; 84:774-81. [DOI: 10.1111/asj.12065] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 02/07/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Wurong Ding
- State Key Laboratory of Pastoral Agricultural Ecosystem; College of Pastoral Agriculture Science and Technology; Lanzhou University; Lanzhou China
| | - Xusheng Guo
- State Key Laboratory of Pastoral Agricultural Ecosystem; Institute of Arid Agroecology; School of Life Sciences; Lanzhou University; Lanzhou China
| | - Kazuo Ataku
- Department of Dairy Science; Rakuno Gakuen University; Ebetsu Japan
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Sabbia JA, Kalscheur KF, Garcia AD, Gehman AM, Tricarico JM. Soybean meal substitution with a yeast-derived microbial protein source in dairy cow diets. J Dairy Sci 2012; 95:5888-900. [PMID: 22863090 DOI: 10.3168/jds.2011-5237] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 05/29/2012] [Indexed: 12/16/2023]
Abstract
The objective of this study was to examine the effects substituting soybean meal with a yeast-derived microbial protein (YMP) on rumen and blood metabolites, dry matter intake, and milk production of high-producing dairy cows. Sixteen Holstein cows (12 multiparous and 4 primiparous), 93 ± 37 DIM (mean ± SD) at the beginning of the experiment, were used in a 4×4 Latin square design with four 28-d periods. Cows were blocked by parity and production, with 1 square consisting of 4 animals fitted with rumen cannulas. Basal diets, formulated for 16.1% crude protein and 1.56 Mcal/kg of net energy for lactation, contained 40% corn silage, 20% alfalfa hay, and 40% concentrate mix. During each period, cows were fed 1 of 4 treatment diets corresponding to YMP (DEMP; Alltech Inc., Nicholasville, KY) concentrations of 0, 1.14, 2.28, and 3.41% DM. Soybean meal (44% CP) was replaced by YMP to attain isonitrogenous and isoenergetic diets. Dietary treatments had no effect on pH and on most ruminal volatile fatty acid concentrations, with the exception of isovalerate, which decreased linearly with the addition of YMP. Rumen ammonia concentration decreased linearly, whereas free amino acids, total amino acid nitrogen, and soluble proteins weighing more than 10 kDa showed a cubic response on rumen N fractionation. A quadratic response was observed in oligopeptides that weighed between 3 and 10 kDa and peptides under 3kDa when expressed as percentages of total amino acids and total nitrogen. Although nonesterified fatty acid concentration in blood did not differ between treatments, β-hydroxybutyrate and plasma glucose increased linearly as YMP increased. Dry matter intake showed a cubic effect, where cows fed 1.14, and 3.41% YMP had the highest intake. Milk production was not affected by YMP, whereas a trend was observed for a quadratic increase for 4% fat-corrected milk and energy-corrected milk. Medium- and long-chain fatty acid concentrations in milk increased quadratically, which elicited similar effects on milk fat concentration and yield. Total solids percentage and yield, and milk urea nitrogen also showed quadratic effects as YMP increased in the diet. No effects were observed on feed efficiency, milk protein, and lactose percentage or yield. A complementary in vitro study demonstrated a quadratic tendency for apparent and true dry matter digestibility as YMP was added to the diet. It was concluded that the substitution of soybean meal with YMP increased the percentage of total solids in milk and tended to improve energy-corrected and fat-corrected milk production in high-producing dairy cows consuming high-forage diets.
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Affiliation(s)
- J A Sabbia
- Dairy Science Department, South Dakota State University, Brookings, SD 57007, USA
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Feuermann Y, Shamay A, Mabjeesh SJ. Leptin up-regulates the lactogenic effect of prolactin in the bovine mammary gland in vitro. J Dairy Sci 2009; 91:4183-9. [PMID: 18946122 DOI: 10.3168/jds.2008-0988] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The ability of leptin to up-regulate prolactin action in the mammary gland is well established. We examined the effect of leptin and prolactin on traits associated with lactation. Leptin and prolactin enhanced proliferation (thymidine incorporation) of the mammary gland cells, elevated the cells' proliferation in a dose-responsive manner, and synergized to elevate the expression of amino acid metabolism via a 90% increase in aminopeptidase N expression. Leptin and prolactin decreased apoptosis (decreased caspase-3 expression by 60%) in the same manner. Leptin enhanced the effect of prolactin on all of these processes in bovine mammary explants. Leptin and prolactin regulated mTOR (mammalian target of rapamycin) by increasing expression by 66%, which is one of the signal-transduction junctions involved in the regulation of proliferation, apoptosis, and protein synthesis. These findings support the hypothesis that leptin up-regulates prolactin action in the bovine mammary gland.
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Affiliation(s)
- Y Feuermann
- Institute of Animal Science, Agricultural Research Organization, the Volcani Center, PO Box 6, Bet Dagan 50250, Israel
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Gilbert ER, Wong EA, Webb KE. Board-invited review: Peptide absorption and utilization: Implications for animal nutrition and health. J Anim Sci 2008; 86:2135-55. [PMID: 18441086 DOI: 10.2527/jas.2007-0826] [Citation(s) in RCA: 210] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Over the last 50 yr, the study of intestinal peptide transport has rapidly evolved into a field with exciting nutritional and biomedical applications. In this review, we describe from a historical and current perspective intestinal peptide transport, the importance of peptides to whole-body nutrition, and the cloning and characterization of the intestinal peptide transporter, PepT1. We focus on the nutritional significance of peptide transport and relate these findings to livestock and poultry. Amino acids are transported into the enterocyte as free AA by a variety of AA transporters that vary in substrate specificity or as di- and tripeptides by the peptide transporter, PepT1. Expression of PepT1 is largely restricted to the small intestine in most species; however, in ruminants, peptide transport and activity is observed in the rumen and omasum. The extent to which peptides are absorbed and utilized is still unclear. In ruminants, peptides make a contribution to the portal-drained visceral flux of total AA and are detected in circulating plasma. Peptides can be utilized by the mammary gland for milk protein synthesis and by a variety of other tissues. We discuss the factors known to regulate expression of PepT1 including development, diet, hormones, diurnal rhythm, and disease. Expression of PepT1 is detected during embryological stages in both birds and mammals and increases with age, a strategic event that allows for the immediate uptake of nutrients after hatch or birth. Both increasing levels of protein in the diet and dietary protein deficiencies are found to upregulate the peptide transporter. We also include in this review a discussion of the use of dietary peptides and potential alternate routes of nutrient delivery to the cell. Our goal is to impart to the reader the nutritional implications of peptide transport and dietary peptides and share discoveries that shed light on various biological processes, including rapid establishment of intestinal function in early neonates and maintenance of intestinal function during fasting, starvation, and disease states.
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Affiliation(s)
- E R Gilbert
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061-0306, USA
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Tagari H, Webb K, Theurer B, Huber T, DeYoung D, Cuneo P, Santos J, Simas J, Sadik M, Alio A, Lozano O, Delgado-Elorduy A, Nussio L, Bittar C, Santos F. Mammary Uptake, Portal-Drained Visceral Flux, and Hepatic Metabolism of Free and Peptide-Bound Amino Acids in Cows Fed Steam-Flaked or Dry-Rolled Sorghum Grain Diets. J Dairy Sci 2008; 91:679-97. [DOI: 10.3168/jds.2007-0629] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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