Whether dietary protein levels or duodenal infusion of amino acids alters the release of cholecystokinin (CCK) in blood plasma of goats was investigated in three experiments. The CCK determination was done by radioimmunoassay with specific CCK-8 antibody. The male adult Shiba goat, a miniature Japanese native goat, was used. 2. In Experiment 1, four goats were offered a diet containing 4.94 g crude protein (CP)/kg BW0.75 for the first 7 days. They were then given a diet containing 5.86 g CP/kg BW0.75 for 7 days and thereafter 6.79 g CP/kg BW0.75 for the following 7 days. On the last day of each experimental period, blood samples were taken from the jugular vein at zero (before feeding), 30, 60, 120, 240 or 360 min after the feeding of the diet. Plasma CCK levels were not affected by dietary protein levels and time after feeding. 3. Influence of phenylalanine or tryptophan (2 mmol/20 ml) infusion into the duodenum was investigated by a 3 x 3 latin square in Experiment 2. Plasma CCK level was determined at 15 min intervals for 1 hr. Both phenylalanine and tryptophan gradually enhanced plasma CCK concentrations with time after infusion. 4. Branched-chain amino acids such as leucine and isoleucine were supplemented intraduodenally in Experiment 3 as in Experiment 2. No significant change in plasma CCK levels was observed.
摘要
在三个实验中，研究了日粮蛋白质水平或十二指肠输注氨基酸是否会改变山羊血浆中胆囊收缩素（CCK）的释放。使用特异性CCK - 8抗体通过放射免疫测定法测定CCK。选用成年雄性柴山羊，这是一种日本本土小型山羊。2. 在实验1中，四只山羊在最初7天饲喂含4.94 g粗蛋白（CP）/kg体重0.75的日粮。然后在接下来7天给予含5.86 g CP/kg体重0.75的日粮，之后在随后7天给予含6.79 g CP/kg体重0.75的日粮。在每个实验期的最后一天，于饲喂日粮后0（饲喂前）、30、60、120、240或360分钟从颈静脉采集血样。血浆CCK水平不受日粮蛋白质水平和饲喂后时间的影响。3. 在实验2中，通过3×3拉丁方研究了十二指肠输注苯丙氨酸或色氨酸（2 mmol/20 ml）的影响。在1小时内每隔15分钟测定一次血浆CCK水平。输注后，苯丙氨酸和色氨酸均随时间逐渐提高血浆CCK浓度。4. 在实验3中，如实验2一样在十二指肠内补充支链氨基酸如亮氨酸和异亮氨酸。未观察到血浆CCK水平有显著变化。
