中文摘要：

将24头仔公猪分为对照组（正常哺乳28d断奶）、试验Ⅰ组（添喂β-酪啡肽-7）和试验Ⅱ组（添喂酪蛋白酶解物）。试验组于21d断奶，再连续添喂酪蛋白胃蛋白酶解液或8-酪啡肽-710d，每天2次（共20mL），至32d，3组动物各随机取6头同时剖杀，取血、胃食糜和空肠食糜。通过所建立的RP—HPLC方法，在胃食糜和空肠食糜中检测到β-酪啡肽-5、β-酪啡肽-7样物质。对照组、酪啡肽-7组和酪蛋白水解液组，β-酪啡肽-7的平均含量分别为21．12±2．38，23．58±7．49、21.81±9．93μg／g胃食糜和16．99±3．48、19．08±2．85、21．36±4．85μg／g肠食糜；胃食糜中G—CM-7的含量高于空肠食糜，试验组均高于对照组。在各组仔猪的血液中未检测到酪啡肽样物质。肠食糜的细胞生物学试验结果表明：与喂仔猪料的对照组比较，试验Ⅰ组和试验Ⅱ组对细胞腺苷酸环化酶的活性均具有不同程度的抑制作用，抑制率分别为27．9％和89．0％，抑制作用均能被纳洛酮反转，逆转率分别是43．2％和89．07％。提示在21日龄断奶仔猪饲料中添加酪啡肽或酪蛋白酶解物，其肠道中有酪啡肽释放，阿片总活性升高。

英文摘要：

24 male piglets were divided into 3 groups randomly： control group （weaning in 28 day＇s old） , Experimental I group （feeding with 10 μmol/L β-CM-7 group） and Experimental II group （casein hydrolysate group ）. Experimental groups were weaned in 21 days and fed with casein hydrolysate and β-CM-7（ 2 times every day, 10 mL every time ）. On 32 days, 6 chosen piglets from each group were killed for determination of stomach , jejunum digesta and blood CMs. The result showed that there were β-CM-5 and t3-CM 7 in stomach and jejunum digesta, average content of β-casomorphin-7 were 21.12±2.38, 23.58±7.49, 21.81±9.93 μg/g stomach digesta and 16.99 ±3.48, 19.08±2.85 and 21.36±4.85 μg/g jejunum digesta, respectively. The concentration of CMs in stomach was higher and two Experimental groups were more than control group. Compared with control group （normal weaning group）, other two groups which fed with β-CM-7 or casein hydrolyates inhibited adenylate cyclase activity of NG108-15 hybrid tumor cell and decreased the intracellular level of cAMP. The ratio of the inhibitions were 27.9% and 89%, and were reversed 43.2% and 89.07% by naloxone. The results indicted that CMs were released by feeding β-CM or casein hydrolysate, and can enhance opioid activity in gut-gastric tract of 21 days＇ weaning piglets.