• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.939-943
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• 1999

Three 28 day-old $Duroc{\times}Large$ $White{\times}Landrace$ litter mate gilts weighing an average of 6.5 kg were used to study the intestinal absorption of amino acids when provided in dipeptide form or in the form of a free amino acid mixture. The pigs were given one of three treatments. The control involved a duodenal infusion containing no amino-acids (phosphate buffer plus 5% sorbitol) while the remaining two treatments involved either a duodenal infusion containing a glycine-lysine dipeptide (1 g) or a mixture of the free amino acids glycine and lysine at the same concentration as in the dipeptide. Blood was drawn from a cannula inserted in the portal vein, at 5 to 20 minute intervals, for two hours following infusion. The concentration of intact dipeptide as well as free glycine and lysine in the portal blood was determined by high performance liquid chromatography. The intact dipeptide was never detected in the portal blood at any time after infusion. Lysine appeared in the portal blood more rapidly after infusion of dipeptide than after infusion of free lysine and the concentration of lysine in portal blood was higher in the pig infused with the dipeptide than after infusion of free lysine at almost all time points measured. The cumulative absorption of lysine and glycine from the intestine during the two hour period after infusion was greater in the pig infused with dipeptide than in the pig infused with free amino acids. The results suggest that although intact dipeptide did not reach he portal circulation, a special transport mechanism for absorption of dipeptide by intestinal cells appears to be present in pigs similar to that observed in other species.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.151-153
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• 1989

• The Korean Journal of Physiology
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• v.16 no.2
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• pp.159-163
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• 1982

Vasoactive intestinal peptide (VIP) found in duodenal mucosa originally has been suggested as a neurotransmitter. Its localization, however, now known, is not limited to the gastrointestinal tract, but scattered at many different kinds of tissues, smooth muscles, endocrine gland and exocrine gland as well as central and peripheral neural tissues. To investigate the effect of VIP on renal function, an experiment has been done in anesthetized male rats. The results obtained were: 1) Urinary output and creatinine clearance decreased significantly during the period of infusion of VIP, 2.0ug/rat/7minutes. 2) Urinary excretion of sodium, potassium and chloride decreased but without significance by infusion of VIP. 3) Blood pressure, systolic and diastolic, decreased by VIP administered intravenously in the period of infusion. 4) Changes of urinary output, sodium and chloride excretion was correlated with changes of creatinine clearance. The above data suggest that VIP administered intravenously can suppress the renal hemodynamics indirectly, and also decrease electrolyte excretion through its renal hemodynamic change.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.733-741
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• 2007

The effects of intra-duodenal infusion of methionine (Met), lysine (Lys) and leucine (Leu) on dry matter intake (DMI), the concentrations of insulin-like growth factor I (IGF-I), growth hormone (GH) and insulin in plasma, and liver IGF-I mRNA level were investigated in two experiments for Liuyang Black growing wether goats. In Experiment 1, three goats ($10.0{\pm}0.1$ kg) were fitted with ruminal, proximal duodenal and terminal ileal fistulaes to determine the infusion amounts of Met, Lys and Leu at the duodenum according to essential amino acid flows into the duodenum and their apparent digestibility. The infusion amounts were 0.77 g/d, 0.91 g/d and 0.58 g/d respectively. In Experiment 2, 4 groups of goats (($10.0{\pm}0.2$ kg) for each group, were cannulated at the duodenum, and were infused with a mixture of Met, Lys and Leu (Control), or mixtures with 21% Met, Lys or Leu replaced with glutamate respectively on a nitrogenous basis. The replacement of 21% Met, Lys or Leu with glutamate did not affect intakes of maize stover, concentrate or both (p>0.05) when compared with the control. The replacement of 21% Met or Lys significantly (p<0.05) reduced plasma GH, insulin and IGF-I concentrations and liver IGF-I mRNA level. The replacement of 21% Leu with glutamate reduced (p<0.05) plasma IGF-I concentration only, but not plasma insulin and GH, as well as liver IGF-I mRNA level (p>0.05). The close relationships between supplying Met and Lys in the lumen of the duodenum and plasma IGF-I, GH and insulin concentrations, as well as liver IGF-I mRNA level in this study indicate that the effects of the limiting amino acids on nutrition of animals are likely intermediated via their effects on these hormones, and these hormone profiles could be used as intermediate markers for the limiting order of amino acids.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1277-1280
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• 2004

The effect of duodenal infusion with feed oligo-peptide solution on portal absorption of amino acids was investigated in poultry under unanaesthetized conditions. Four peptide solutions were used in the experiment: enzymatic hydrolysates from fish meal, soybean meal, cottonseed meal and rapeseed meal proteins with average molecular weights less than 3,000 Da and 1,000 Da, respectively. Intestinal absorptions of these oligo-peptide solutions were compared by determining the concentration of free amino acid (FAA) in portal blood after the duodenal administrations of oligo-peptide solutions. Absorptive intensity and balance were used to estimate the intestinal absorption rate of amino acids. The absorptive intensities of amino acids were highest for the fish and soybean meal oligo-peptides. The ratios of amino acids absorbed in the portal blood from fish and soybean meal oligo-peptides were more similar to the composition of the infused amino acids than that observed from the cottonseed and rapeseed meal oligo-peptides. A positive correlation was found between absorption rate and proportion of PAA in the oligo-peptides. The higher absorption rate could be contributed to the higher proportion of peptide bound amino acids (PAA). The results suggest that fish and soybean meal protein are significantly more easily hydrolyzed into oligo-peptides (p<0.05) in the gastrointestinal tracts of poultry and as such can be utilized more effectively by body tissues.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.72-81
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• 2013

Four Luxi beef cattle ($400{\pm}10$ kg) fitted with ruminal, duodenal and ileal cannulas were used in a $4{\times}4$ Latin square to assess the effects of soybean small peptide (SSP) infusion on rumen fermentation, diet digestion and flow of nutrient in the gastrointestinal tract. The ruminal infusion of SSP was 0 (control), 100, 200 and 300 g/d. Ruminal SSP infusion linearly (p<0.01) and quadratically (p<0.01) increased microbial protein synthesis and rumen ammonia-N concentration. Concentrations of total volatile fatty acid were linearly increased (p = 0.029) by infusion SSP. Rumen samples were obtained for analysis of microbial ecology by real-time PCR. Populations of rumen Butyrivibrio fibrisolvens, Streptococcus bovis, Ciliate protozoa, Ruminococcus flavefaciens, and Prevotella ruminicola were expressed as a proportion of total Rumen bacterial 16S ribosomal deoxyribonucleic acid (rDNA). Butyrivibrio fibrisolvens populations which related to total bacterial 16S rDNA were increased (p<0.05), while Streptococcus bovis populations were linearly (p = 0.049) and quadratically (p = 0.020) decreased by infusion of SSP. Apparent rumen digestibility of DM and NDF were (Q, p<0.05; L, p<0.05) increased with infusion SSP. Total tract digestion of DM, OM and NDF were linearly (p<0.01) and quadratically (p<0.01) increased by infusing SSP. The flow of total amino acids (AA), essential amino acids (EAA) and individual amino acids were linearly (p<0.01) and quadratically (p<0.01) increased with infusion SSP. The digestibility of Lysine was quadratically (p = 0.033) increased and apparent degradability of Arginine was linearly (p = 0.032) and quadratically (p = 0.042) increased with infusion SSP. The results indicated that infusion SSP could improve nutrient digestion, ruminal fermentation and AA availability.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.1-6
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• 2003

Catechins exhibit a hypocholesterolemic effect in cholesterol-fed animals. The present study was conducted to examine whether (+)-catechin influences the absorption of cholesterol in rats. Male Sprague-Dawley rats were fed ad libitum an AIN-93G diet containing soybean oil for 5 wk. Rats with lymph cannulae were infused at 3.0 mL/h for 8 h via a duodenal catheter with a lipid emulsion containing radiolabeled cholesterol with or without (+)-catechin. Lymph was collected hourly for 8 h. The enteral infusion of (+)-catechin significantly lowered the lymphatic absorption of $^{14}$ C-cholesterol (21.1 $\pm$ 3.6% dose/B h) compared with controls infused with the lipid emulsion devoid of (+)-catechin (38.2 $\pm$ 1.2% dose/8 h). The intestinal absorption of $\alpha$-tocopherol (24.2$\pm$3.0% dose/8 h) also was significantly decreased by (+)-catechin infusion, relative to controls (32.2$\pm$2.2% dose/8 h). However, the lymphatic outputs of oleic acid and phospholipid were not affected by enteral (+)-catechin infusion. The results indicate that (+)-catechin has a profound inhibitory effect on the intestinal absorption of cholesterol and $\alpha$-tocopherol without affecting the absorption of fat.

• Journal of Animal Environmental Science
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• v.3 no.1
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• pp.1-12
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• 1997

This study was conducted to investigate the combined effects of VFA composition of rumen fluid and heat exposure (30${\pm}$2$^{\circ}C$) on the general clinical view and insulin secretory response to glucose in sheep. The total infusion of nutrients was examined in sheep via the technique of continuous alimentation. Four adult Suffolk sheep fitted with a permanent ruminal cannula and a simple T-shaped duodenal cannula were used. A peristaltic pump was used to infuse the solutions of volatile fatty acid triglycerides (VFA-TG) consisting of 70 triacetin : 20 tripropionin : 10 tributyrin (low propionin division: LP) and 50 triacetin : 40 tripropionin : 10 tributyrin (high propionin division: HP) on the basis of energy and minerals into the rumen, and casein solution into the duodenum. The effects of heat exposure and type of the levels of VFA-TG solutions on the insulin secretory response to glucose in sheep were investigated by using hyperglycemic clamp (HGC) technique. The results obtained are summarized as follows: 1. During the heat exposure (latter half of the infusion period), respiration rate, heart rate and rectal temperature increased (P＜0.01, P＜0.01, P＜0.05), but the levels of VFA-TG solutions (LP and HP division) did not affect the general clinical view except for the heart rate. 2. In the HGC technique, glucose infusion rate (GIR) and mean plasma insulin increments (MPII) tended to be ower in the heat exposure than in the thermoneutral environment, but no significant difference was found among the treatments. GIR and MPII remained unchanged between the levels of VFA-TG solutions. 3. In the HGC technique, ratio of MPII to GIR (MPII/GIR) which represents pancreatic ${\beta}$-cell response to glucose stimulation remained unchanged among the treatments.

• The Korean Journal of Pharmacology
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• v.9 no.2
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• pp.17-27
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• 1973

Modifying the technique described by Schmidt, et al. (1972) the duodenum and stomach of female rats were perfused separately and contiunously with saline solution under urethane anesthesia. Secretory response of caerulein (Prof. V. Erspamer, F.I. 6934 Caerulein, Farmitalia, Italia), a gastrin or CCK-PZ like peptide, on acid, pepsin, bicarbonate and amylase were studied with and without simultaneous administration of secretin, CCK-PZ or other agents known secretory suppressives. A significant increase of acid, pepsin and amylase output was induced by intravenous infusion of caerulein. The response of acid secretion by caerulein in doses of 140 ng/100g/hr was equivalent to the response of histamine in the doses of $280\;{\mu}g/100g/hr$ and on a weight basis the potency of caerulein was approximately 2,000 times greater than histamine in rats. Acid secretory response of caerulein in the doses of 140 ng/100 g/hr was inhibited by simultaneous infusion of secretin in the doses of 0.2 u/ 100 g/hr, and the acid response was partly inhibited by concomitant infusion of histamine in the doses of $280\;{\mu}g/100g/hr$, but the response was enhanced by infusion of CCK-PZ in the doses of 0.2 u/100 g/hr. The secretory response of both aicd and enzymes were inhibited following administration of atropine in doses of 0.2 mg/100 g, but the response were not affected by hexamethonium in doses of 0.5 mg/100 g. In summary, it is concluded that caerolein is every effective in an increase of acid, pepsin and amylase secretion in rats through, possibly in part, the muscarinic and/or histaminic mechanism(s).

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.104-109
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• 2011

Recently, we have demonstrated that green tea extract (GTE) decreases the intestinal absorption of benzo[a]pyrene (BAP), which is an extremely lipophilic food contaminant. The present study was conducted to examine if an enteral infusion of GTE would influence the biliary secretion of BAP and lipids in rats. Female rats were fed an AIN-93G diet with or without (control) GTE at 5 g/kg diet for 4 week. Following the 4-week dietary treatment, rats with bile duct cannula were infused continuously for 8 hr at 3.0 mL/hr via a duodenal catheter with a lipid emulsion containing $4.0\;{\mu}mol$ BAP labeled with $^{14}C$ ($^{14}C$-BAP), $20.7\;{\mu}mol$ cholesterol, $452\;{\mu}mol$ triolein, and $3.1\;{\mu}mol$ ${\alpha}$-tocopherol, and $396.0\;{\mu}mol$ Na-taurocholate with or without 76.1 mg GTE powder in PBS buffer (pH, 6.4). Bile was collected hourly via bile cannula for an 8 hr period. Our results showed that bile flow did not differ between groups. However, the biliary secretion of $^{14}C$-BAP was significantly enhanced by GTE infusion, compared with those infused with the lipid emulsion alone. However, GTE did not affect the biliary outputs of cholesterol, fat, phospholipid and ${\alpha}$-tocopherol. These findings indicate that GTE has a profound stimulatory effect on the biliary excretion of BAP in rats, without affecting other biliary lipids. The mechanism(s) by which GTE enhances the biliary secretion of BAP remains to be investigated.