College of Animal Science and Technology, Northwest A&F University, Shaanxi, Yangling, China.
J Anim Physiol Anim Nutr (Berl). 2013 Jun;97(3):431-8. doi: 10.1111/j.1439-0396.2012.01276.x. Epub 2012 Feb 22.
Four yearling goats (31.2 ± 2.5 kg), surgically fitted with common bile duct reentrant and duodenal catheter, were used in two 4 × 4 Latin square design experiments to investigate the effects of duodenal infusion of phenylalanine for different times on pancreatic exocrine secretion (PES). In experiment 1 (the long-term experiment), goats were duodenally infused with 0, 2, 4 or 8 g/day phenylalanine for 14 day. Pancreatic juice and jugular blood samples were collected over 1-h intervals for 6 h daily from day 11 to day 14 to encompass a 24-h day. In experiment 2 (the short-term experiment), goats were infused with phenylalanine for 10 h continuously at the same infusion rate as experiment 1 after feed deprivation for 24 h repeated every 10 day. Pancreatic juice and blood samples were collected at 0, 1, 2, 4, 6, 8 and 10 h of infusion. The volume and pH of pancreatic juice were measured, and a 5% subsample was composited and frozen until analysis of enzyme activities. Plasma was frozen until analysis of insulin and cholecystokinin (CCK). In experiment 1, pancreatic juice, α-amylase secretion and plasma CCK concentration responded quadratically (p < 0.05), with the top value observed at the 2 g/day phenylalanine. Trypsin secretion had a quadratic response (p < 0.05), with secretion increasing up to 4 g/day phenylalanine and decreasing thereafter. Phenylalanine linearly decreased pancreatic protein and lipase secretion (p < 0.05). The results of correlation analysis showed significant correlations (p < 0.05) between plasma CCK concentration and secretion of α-amylase and trypsin. However, the short-term phenylalanine infusion did not influence (p > 0.05) pancreatic juice, protein, α-amylase, lipase, trypsin secretion and plasma CCK concentration. These results indicate PES of ruminants is stimulated by phenylalanine and is potentially mediated by CCK in the long-term duodenal infusion treatment, but is not influenced by phenylalanine in the short-term duodenal infusion treatment.
将 4 只 4 月龄、体重为（31.2±2.5）kg 的山羊，通过手术安置胆总管可回收式和十二指肠导管，用于两项 4×4 拉丁方设计实验，以研究十二指肠输注不同时间苯丙氨酸对胰腺外分泌分泌（PES）的影响。在实验 1（长期实验）中，山羊连续 14 天每天十二指肠输注 0、2、4 或 8g/天苯丙氨酸。从第 11 天到第 14 天，每天采集 1 小时间隔的胰腺分泌液和颈静脉血样，以涵盖 24 小时/天。在实验 2（短期实验）中，在禁食 24 小时后，每隔 10 天连续 10 小时以与实验 1 相同的输注率连续输注苯丙氨酸。在输注的 0、1、2、4、6、8 和 10 小时采集胰腺分泌液和血液样本。测量胰腺分泌液的体积和 pH 值，取 5%的亚样本混合并冷冻，直到分析酶活性。冷冻血浆，直到分析胰岛素和胆囊收缩素（CCK）。在实验 1 中，胰腺分泌液、α-淀粉酶分泌和血浆 CCK 浓度呈二次曲线反应（p<0.05），在 2g/天苯丙氨酸时达到最高值。胰蛋白酶分泌呈二次反应（p<0.05），分泌量增加到 4g/天苯丙氨酸，然后减少。苯丙氨酸线性降低胰腺蛋白质和脂肪酶分泌（p<0.05）。相关分析结果表明，血浆 CCK 浓度与 α-淀粉酶和胰蛋白酶分泌呈显著相关（p<0.05）。然而，短期苯丙氨酸输注不影响（p>0.05）胰腺分泌液、蛋白质、α-淀粉酶、脂肪酶、胰蛋白酶分泌和血浆 CCK 浓度。这些结果表明，在长期十二指肠输注治疗中，苯丙氨酸刺激反刍动物的 PES，可能由 CCK 介导，但在短期十二指肠输注治疗中，苯丙氨酸不受影响。
