胃扩张刺激对大鼠大脑皮层及海马CCK mRNA表达的影响

胆囊收缩素（ｃｈｏｌｅｃｙｓｔｏｋｉｎｉｎ,ＣＣＫ）是脑肠肽中的一种,被认为是饱因子。本实验采用以地高辛标记的ＣＣＫ ｃＤＮＡ为探针的原位杂交和半定量ＲＴ－ＰＣＲ技术。用水囊扩张胃作为对胃壁的机械刺激模拟食物对胃的充盈作用,观察大鼠大脑皮层和海马内含ＣＣＫ神经元ＣＣＫ ｍＲＮＡ表达的变化情况。

Changes in the mRNA concentration of preprocholecystokinin in rat cerebral cortex and hippocampus after gastric distension

Cholecyctokinin-octapeptide (CCK-8) is one of the brain-gut peptides widelydistributed in neurons of the central nervous system, especially in cerebral cortex andhippocampus. This peptide is thought as a neurotransmitter or modulator. The role ofcentral CCK in the integration of gastric motility and food intake is still unclear. Thepresent investigation was undertaken to see whether the gastric distension exerts someeffect on the expression of CCK mRNA in cerebral cortex and hippocampus by means ofin situ hybridization and semi-quantative RT-PCR techniques. The results are as follows.(1) Discrete positive hybridization cells were seen in cerebral cortex and hippocampus incontrol group. (2) Significant increases of CCK mRNA expression in cerebral cortex andhippcompus produced by gastric distention observed by increased of the volume, thenumber, the IOD and the SA of positive cells. (3) Amplified bands of the expected size of 158 base pairs were found in cerebral cortex and hippocampus, and signals of gastricdistention group were higher than those of control group. The results from RT-PCR assayare in agreement with those based on in situ hybridization. These results imply thatbiosynthesis of CCK-containing neurons in cerebral cortex and hippocampus is acceleratedby afferent signals from gastrointestinal system and may be involved in regulation of gastricmotility and food intake.