摘要
目的:本实验研究了β酪啡肽7在成年大鼠十二指肠内的吸收和稳定特性及其对胆囊收缩素表达的影响。方法:(1)比较吸收和阻断吸收两种状态下灌注的β酪啡肽7浓度变化,从而定性判断其在成年大鼠肠道内的吸收特性;(2)体外酶解实验观察β酪啡肽7对大鼠十二指肠黏膜的酶解特性;(3)半定量RT-PCR法检测灌喂β酪啡肽7对肠黏膜胆囊收缩素和生长抑素基因表达的变化。结果:β酪啡肽7在成年大鼠十二指肠内不被吸收但被肠黏膜酶快速降解,且显著刺激肠黏膜中胆囊收缩素基因的表达,该效应被纳洛酮部分逆转;β酪啡肽7显著抑制生长抑素基因表达。结论:除了内源性阿片肽系统外,β酪啡肽还可能通过抑制生长抑素基因表达来促进肠粘膜中胆囊收缩素的表达,从而影响肠运动机能。
Objective： The aim of the present study was to evaluate the stability of native bovine β casomorphin 7 in duodenum of adult rats, and the local effect on expression of cholecystokinin in intestinal mucosa. Method： （1） According to the variety of infused β casomorphin 7 concentrations between absorptive and un-absorptive groups in vivo, its characteristic absorption in duodenum was observed. （2） To characterize the stability of the β casomorphin 7, rat intestinal mucosa homogenate was digested and the enzyme activities were determined in vitro. （3） The effect on cholecystokinin mRNA expression of β casomorphin 7 after luminal administration was analyzed by RT-PCR. Results：β casomorphin 7 was unable to be absorbed by intestinal epithelia and quickly degraded in the intestinal tract. It contributed to elevate cholecystokinin mRNA expression in intestinal mucosa and this effect was partly blocked by naloxone. This peptide also significantly inhibited the somatostatin mRNA expression. Conclusion： The present data demonstrated that the local effect on expression of cholecystokinin of β casomorphin 7 might be related to opioid system and directly or indirectly affected by somatostatin.
出处
《营养学报》
CAS
CSCD
北大核心
2007年第4期396-400,共5页
Acta Nutrimenta Sinica
基金
国家自然科学基金(No.30070565)
