摘要
为了探讨主要的乳源活性肽β-酪啡肽(β-casomorphins,β-CMs)对大鼠小肠葡萄糖吸收及血糖浓度的影响,本试验从体外和体内2个方面对其进行了初步研究。体外试验利用翻转的离体小肠囊研究了浓度为0(对照组)、7.5×10-5(高剂量组)、7.5×10-6(中剂量组)、7.5×10-7mol/L(低剂量组)的β-CM7和β-CM5对离体小肠囊葡萄糖吸收的影响,同时选用阿片特异性阻断剂纳洛酮与β-CM7按物质的量比2∶1混合,探讨影响葡萄糖吸收的阿片机制。体内试验选用健康成年SD大鼠21只,随机分为对照组(灌胃生理盐水)、β-CM7组(灌胃7.5×10-6mol/Lβ-CM7)和β-CM5组(灌胃7.5×10-6mol/Lβ-CM5)。连续灌胃30d后,断颈处死,取血液、肝脏及肌肉,检测血清中葡萄糖和胰岛素含量以及体内肝糖原、肌糖原含量。体外试验结果显示,不同浓度的β-CM7和β-CM5(7.5×10-7～7.5×10-5)均能抑制离体小肠囊对葡萄糖的吸收,抑制作用的大小与浓度有关;加入纳洛酮阻断剂后没有逆转β-CM7对小肠囊葡萄糖吸收的抑制效用。体内试验结果显示,与对照组相比,试验后期β-CM7组和β-CM5组大鼠的血糖浓度和肌糖原含量均极显著降低(P<0.01),血清胰岛素含量无显著变化(P>0.05);β-CM5组的肝糖原含量极显著降低(P<0.01)。以上结果提示,β-CM7和β-CM5具有辅助降血糖作用,其降糖机制可能与肌糖原的消耗和非阿片途径抑制小肠葡萄糖的吸收有关。
To investigate the effects of β-casomorphins（β-CMs）,one of the primarily milk-derived bioactive peptides,on glucose absorption of the small intestine and serum glucose concentration in rats,in vitro and in vivo experiments were conducted in this study.In the in vitro experiment,the effects of β-CM7 and β-CM5 at concentrations of 0（control group）,7.5×10-5（high-dose group）,7.5×10-6（medium-dose group） and 7.5×10-7 mol/L（low-dose group） on intestinal absorption of glucose were studied by using reversed small intestine sac.At the same time,the combination of naloxone（special blocker of opioid receptor） and β-CM7（2∶1,molar ratio） was used to investigate the opioid mechanism of β-CM7 on intestinal absorption of glucose.In the in vivo experiment,twenty-one healthy adult Sprague-Dawley（SD） rats were randomly divided into control group（intragastric physiological saline infusion）,β-CM7 group（intragastric 7.5×10-6 mol/L β-CM7 infusion） and β-CM5 group（intragastric 7.5×10-6 mol/L β-CM5 infusion）.After 30-day experiment,the rats were killed by breaking off the neck,and the blood,liver and muscle were sampled for testing serum glucose and insulin levels,and the contents of hepatic glycogen and muscle glycogen.The results of in vitro experiment showed that,β-CM7 and β-CM5 at all different concentrations（7.5×10-7 to 7.5×10-5 mol/L） could inhibit the intestinal absorption of glucose in vitro in a dose-dependent manner,and naloxone addition did not reverse the inhibition of β-CM7 on the in vitro absorption of glucose in small intestine.The results of in vivo experiment showed that,in later period of the experiment,the concentration of serum glucose and the content of muscle glycogen in β-CM7 and β-CM5 groups were lower than those of the control group（P0.01）,and the content of hepatic glycogen in β-CM5 group was lower than that of the control group（P0.01） while the content of serum insulin showed little disparity in comparison with that of the control g
出处
《动物营养学报》
CAS
CSCD
北大核心
2010年第4期1081-1087,共7页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家大学生创新性实验计划项目(GJ0712)
关键词
Β-酪啡肽
大鼠
葡萄糖
小肠吸收
血糖
β-casomorphin
Rats
Glucose
Absorption of the small intestine
Serum glucose
