尾状核、黑质、迷走神经背核内参与尾状核P物质抑制胃运动效应的递质

在向大鼠尾状核微量注射 P物质引起胃肌电和运动出现抑制效应时 ,应用免疫细胞化学的方法观察了尾状核、黑质、迷走神经背核内 P物质、酪氨酸羟化酶、胆碱乙酰化酶和γ-氨基丁酸免疫活性的变化。藉以探讨尾状核 P物质的抑胃效应与经典递质多巴胺、乙酰胆碱和 γ-氨基丁酸的关系。结果如下 :(1)尾状核内合成多巴胺的限速酶酪氨酸羟化酶免疫反应阳性纤维活性明显增强 ,乙酰胆碱的合成酶 -胆碱乙酰化酶免疫反应阳性细胞体数目显著增加 ,γ-氨基丁酸细胞体免疫反应活性明显增强。(2 )黑质内γ-氨基丁酸能纤维免疫反应活性显著增强 ,胆碱乙酰化酶免疫反应阳性细胞数目也显著增加 ,P物质和酪氨酸羟化酶免疫反应无明显变化。 (3)迷走神经背核内胆碱乙酰化酶免疫反应阳性细胞数目显著减少 ,P物质、γ-氨基丁酸免疫反应细胞数目显著增加。本研究提示 :尾状核内的多巴胺、乙酰胆碱、γ-氨基丁酸 ,黑质内的γ-氨基丁酸、乙酰胆碱和迷走神经背核内的 P物质、γ-氨基丁酸、乙酰胆碱等可能参与尾状核 P物质的抑胃效应

NEUROTRANSMITTERS INVOLVED IN INHIBITORY EFFECT OF SUBSTANCE P OF CAUDATE NUCLEUS ON GASTRIC MYOELECTRIC ACTIVITY AND MOTILITY IN CAUDATE NUCLEUS, SUBSTANTIA NIGRA AND DORSAL VAGAL NUCLEUS

In the present study, the inhibitory effect on gastric myoelectric activity and motility were induced after microinjection of SP into the caudate nucleus, and changes of immunoreactivity of substance P(SP), tyrosin hydroxylase (TH), choline acetyltransferase (ChAT) and γ-aminobutyric acid (GABA) in caudate nucleus, substantia nigra and dorsal vagal nucleus were observed by immunocytochemical staining technique respectively: in order to investigate the inhibitory effect of SP of caudate nucleus and its relation to dopamine, aceylcholine as well as GABA. The results revealed that: (1)both TH-immunoreaactivity of fibers and the number of ChAT positive cells were increased in caudate nucleus; meanwhile, GABA-immunoreactivity of cells were increased. (2)The number of GABA positive fibers and ChAT-immunoreactvity of cells were reduced in dorsal vagal nucleus; whille that of SP-and TH-immunoreactivity were not. (3) The number of ChAT-immunoreactivity of cells were reduced in dorsal vagal nucleus; while that of SP-and GABA-imunoreactivity were increased. Taking togather, it is suggested that DA, ACh in caudate nucleus, GABA and ACh in substantia nigra and SP, GABA and ACh in dorsal vagal nucleus presumably participate in the inhibitory effect of SP of caudate nucleus on gastric myoelectric activity and motility. (Figures 1～4 on plate 14)