Effect of duodenal infusion of leucine and phenylalanine on intestinal enzyme activities and starch digestibility in goats

Yu, Zhengqing; Wang, F.; Liu, K.; Yao, Jun; Wu, Zhiguo; Qin, Dingkui; Sun, Feifei

doi:10.1016/j.livsci.2014.01.023

Cited by 15 publications

(16 citation statements)

References 26 publications

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“…Leucine has been shown to regulate the secretion of pancreatic insulin (Yang et al, 2015). In this study, both leucine and phenylalanine showed no significant effect on the activity and gene expression of pancreatic α-amylase in calves, which is not consistent with the research results of Liu et al (2015) in dairy cows and Yu et al (2013Yu et al ( , 2014 in adult dairy goats. Such discrepancy may be due to the differences in age of the animals and starch levels in the diets.…”

Section: Discussioncontrasting

confidence: 96%

“…By infusing casein, EAA, NEAA, and glutamate into the duodenum, Brake et al (2014) found that casein and EAA increased the secretion of pancreatic amylase without affecting the starch digestibility in the small intestine, whereas NEAA and glutamate increased the starch digestibility (steer initial BW = 259 kg). Yu et al (2014) showed that both protein and AA could influence the activities of pancreatic enzymes and the expression of their genes in yearling ewes (initial BW = 297 kg) by altering pancreas development.…”

Section: Introductionmentioning

confidence: 99%

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Effects of dietary leucine and phenylalanine on pancreas development, enzyme activity, and relative gene expression in milk-fed Holstein dairy calves

Cao

Yang

Guo

et al. 2018

Journal of Dairy Science

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This study aimed to investigate the effect of dietary supplementation with leucine and phenylalanine on pancreas development, enzyme activity, and related gene expression in male Holstein calves. Twenty male Holstein calves [1 d of age, 38 ± 3 kg of body weight (BW)] were randomly assigned to 1 of the following 4 treatment groups with 5 calves in each group: control, leucine supplementation (1.435 g/L of milk), phenylalanine supplementation (0.725 g/L of milk), and leucine and phenylalanine (1.435 + 0.725 g/L of milk). The diets were made isonitrogenous with the inclusion of alanine in each respective treatment. The feeding trial lasted for 8 wk, including 1 wk for adaption and 7 wk for the feeding experiment. Leucine tended to increase the concentration of total pancreatic protein (mg/kg of BW). Phenylalanine increased the concentrations of plasma insulin, cholecystokinin, and pancreatic DNA (mg/g) and the expression of trypsin gene but decreased the pancreatic protein:DNA ratio and tended to decrease the pancreas weight (g/kg of BW). No differences were observed in total pancreatic DNA (mg/pancreas and mg/kg of BW), pancreatic protein (mg/pancreas), or activities of α-amylase, trypsin, and lipase. The relative expression levels of the genes encoding α-amylase and lipase did not differ among the 4 groups. The supplementation of both leucine and phenylalanine showed an interaction on the pancreas weight (g and g/kg of BW) and a tendency of an interaction on the pancreatic protein concentration (mg/g of pancreas and mg/kg of BW) and the plasma glucose concentration. Leucine tended to increase the size of the pancreatic cells, whereas phenylalanine tended to increase the number of pancreatic cells. However, neither AA affected the activities of the pancreatic enzymes of the calves. These results indicate that leucine and phenylalanine supplementation in milk-fed Holstein calves differentially affect pancreatic growth and development.

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Section: Discussioncontrasting

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Effects of dietary leucine and phenylalanine on pancreas development, enzyme activity, and relative gene expression in milk-fed Holstein dairy calves

Cao

Yang

Guo

et al. 2018

Journal of Dairy Science

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“…Most of these studies reported steady amounts of trypsin or chymotrypsin activities in concert with the steady flows of microbial protein in the ruminant small intestine. However, adaptation did occur with changes in activity up to 1.5-fold common with the highest being 2.0- (Swanson et al, 2004) to 2.85-fold increases (Yu et al, 2014b). Contrast this with changes up to 6-fold reported in rats (Brannon, 1990) and it appears ruminant pancreatic protease activity is less responsive to changes in diet.…”

Section: Pancreatic Proteasesmentioning

confidence: 71%

“…However, these studies (Yu et al, 2013 and indicate that phenylalanine and leucine have the ability to up-regulate pancreatic α-amylase secretion, whereas the combination of phenylalanine plus tryptophan plus methionine did not increase small intestinal starch digestion in steers (Brake et al, 2014a). These observations were confirmed in goats receiving duodenal infusions of leucine (3 and 9 g/day) and phenylalanine (2 g/day) that were slaughtered and enzyme activity in the small intestine measured (Yu et al, 2014b). The infusion of leucine and phenylalanine caused large increases in pancreatic α-amylase activity in the proximal small intestine and tended to increase small intestinal starch digestibilty.…”

Section: Small Intestinal Starch Digestionmentioning

confidence: 82%

Review: Nutritional regulation of intestinal starch and protein assimilation in ruminants

Harmon

Swanson

2020

Animal

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Pregastric fermentation along with production practices that are dependent on high-energy diets means ruminants rely heavily on starch and protein assimilation for a substantial portion of their nutrient needs. While the majority of dietary starch may be fermented in the rumen, significant portions can flow to the small intestine. The initial phase of small intestinal digestion requires pancreatic α-amylase. Numerous nutritional factors have been shown to influence pancreatic α-amylase secretion with starch producing negative effects and casein, certain amino acids and dietary energy having positive effects. To date, manipulation of α-amylase secretion has not resulted in substantial changes in digestibility. The second phase of digestion involves the actions of the brush border enzymes sucrase-isomaltase and maltase-glucoamylase. Genetically, ruminants appear to possess these enzymes; however, the absence of measurable sucrase activity and limited adaptation with changes in diet suggests a reduced capacity for this phase of digestion. The final phase of carbohydrate assimilation is glucose transport. Ruminants possess Na+-dependent glucose transport that has been shown to be inducible. Because of the nature of pregastric fermentation, ruminants see a near constant flow of microbial protein to the small intestine. This results in a nutrient supply, which places a high priority on protein digestion and utilization. Comparatively, little research has been conducted describing protein assimilation. Enzymes and processes appear consistent with non-ruminants and are likely not limiting for efficient digestion of most feedstuffs. The mechanisms regulating the nutritional modulation of digestive function in the small intestine are complex and coordinated via the substrate, neural and hormonal effects in the small intestine, pancreas, peripheral tissues and the pituitary—hypothalamic axis. More research is needed in ruminants to help unravel the complexities by which small intestinal digestion is regulated with the aim of developing approaches to enhance and improve the efficiency of small intestinal digestion.

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“…Swanson [9] reports that increasing diet protein percentage increased the secretion of α-amylase in the pancreas of beef steers. It has been suggested that duodenal infusion of Leu increased the secretion of α-amylase in the pancreas of dairy goats and Holstein heifers [10,11]. Zhao's data [12] showed that Ile can increase digestive enzyme activities of intestine and hepatopancreas in juvenile Jian crap.…”

Section: Introductionmentioning

confidence: 99%

Effects of Branched Chain Amino Acids on digestive enzymes secretion from pancreas of dairy cows

Wang

et al. 2019

Preprint

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Background : The limited ability of ruminant to digest starch in the small intestine may be attributed to insufficient digestive enzyme activity secreted by the pancreas. The purpose of this study was to investigate effects of leucine (Leu), isoleucine (Ile) and valine (Val) on digestive enzymes secretion from pancreas collected of Holstein dairy cows by tissue incubation in vitro. Methods: Two experiments were designed in the present study. In experiment 1, Five Holstein dairy cows were slaughtered and pancreatic tissue was removed immediately, rinsed with ice-cold normal saline (0.9% Nacl) and cut into small segments (approximately 2 × 2 mm), which were placed in oxygenated Krebs Ringer bicarbonate buffer (KRB) containing no amino acid (control), leu, Ile or Val (2.62, 5.24 or 10.48 mg/mL). Each treatment was repeated for five times and incubated in a 39°C shaker. KRB and pancreatic tissue samples were collected at 60, 120 and 180 min after the incubation. In experiment 2, Five Holstein dairy cows were slaughtered and the pancreatic tissue was immediately removed and treated, which were placed in KRB containing no amino acid (control), leu, Ile or Val (5.24 mg/mL) for incubation 60 min. Results : In experiment 1, The activity of pancreatic α-amylase were increased by Leu ( P < 0.01), Ile ( P < 0.01) or Val ( P = 0.06). Compared with the control group, Leu ( P < 0.05) or Ile ( P < 0.05) could linearly increase the activity of trypsin, but Val ( P > 0.05) had no effect on the trypsin activity. Neither Leu or Val had no influence on the activity of chymotrypsin ( P > 0.05). However, chymotrypsin activity decreased linearly with the increase of the Ile concentration at incubation time 180 min ( P < 0.01). Lipase activity were reduced linearly by Val ( P < 0.05 ). In experiment 2, Leu and Val markedly increased α-amylase activity ( P < 0.05), decreased lipase activity ( P < 0.05). The activities of trypsin and chymotrypsin were not affected by the three amino acids ( P > 0.05), and there was no interaction among them ( P > 0.05). Conclusion: This study demonstrated that Leu, Ile and Val can stimulate the secretion of pancreatic enzymes in vitro, especially α-amylase. There was no interaction between the three amino acids on the activities of α-amylase, trypsin and chymotrypsin.

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Effect of duodenal infusion of leucine and phenylalanine on intestinal enzyme activities and starch digestibility in goats

Cited by 15 publications

References 26 publications

Effects of dietary leucine and phenylalanine on pancreas development, enzyme activity, and relative gene expression in milk-fed Holstein dairy calves

Effects of dietary leucine and phenylalanine on pancreas development, enzyme activity, and relative gene expression in milk-fed Holstein dairy calves

Review: Nutritional regulation of intestinal starch and protein assimilation in ruminants

Effects of Branched Chain Amino Acids on digestive enzymes secretion from pancreas of dairy cows

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