Effect of Intracerebral Injection of Substance P on Pain Threshold,Electroacupuncture Analgesia and Met-enkephalin Level in Rat Brain  

作　　者：李希成 阮怀珍 赵邦云 袁和 刘祚周 

机构地区：[1]Department of Physiology,Third Military Medical College,Chongqing 630038,China

出　　处：《Journal of Medical Colleges of PLA(China)》1990年第3期227-231,共5页中国人民解放军军医大学学报（英文版）

摘　　要：Radioimmunoassay was employed to dctermine the immunorcactivc met-enkephalin(ir-MEK)contents of several brain regions .The pain threshold(PT)andir-MEK content of striatum and hypothalamus increased markedly afterintraoerebroventricular injection of substance P(SP)in the dosage of lμgg/10μl ,but nosignificant change of ir-MEK content in hippocampus was observed.When theperiaqueductal gray(PAG)was destroyed with electrolysis,the increase of PT andir-MEK content in the two brain regions after SP injection was obviouslysuppressed(P【0.05-0.01).The PT and ir-MEK content of hypothalamus andstriatum would also increase after intra-PAG injection of SP(0.4μg/4μl),electroacupuncture or intraperitoneal injection of morphine.The ir-MEK content ofhippocampus could also increase after intra-PAG injection of SP or intraperitoncal injec-tion of morphine.The combination of intra-PAG injection of SP andelectroacupuncture caused a more marked elevation of PT and ir-MEK content of the 3brain regions than either of the two used singly could(P【0.01 ).The combined effect ofintra-PAG injection of SP and intraperitoneal injection of morphine was similar to thatof either of the two used singly(P】0.05).These facts indicate that thc analgesic effect ofSP activated by PAG was mediated through the increase of cerebral met-cnkcphalin con-tent,and there was a synergic effect between SP and elcctroacupuncturc.Radioimmunoassay was employed to dctermine the immunorcactivc met- enkephalin(ir-MEK)contents of several brain regions .The pain threshold(PT)and ir-MEK content of striatum and hypothalamus increased markedly after intraoerebroventricular injection of substance P(SP)in the dosage of lμgg/10μl ,but no significant change of ir-MEK content in hippocampus was observed.When the periaqueductal gray(PAG)was destroyed with electrolysis,the increase of PT and ir-MEK content in the two brain regions after SP injection was obviously suppressed(P<0.05-0.01).The PT and ir-MEK content of hypothalamus and striatum would also increase after intra-PAG injection of SP(0.4μg/4μl), electroacupuncture or intraperitoneal injection of morphine.The ir-MEK content of hippocampus could also increase after intra-PAG injection of SP or intraperitoncal injec- tion of morphine.The combination of intra-PAG injection of SP and electroacupuncture caused a more marked elevation of PT and ir-MEK content of the 3 brain regions than either of the two used singly could(P<0.01 ).The combined effect of intra-PAG injection of SP and intraperitoneal injection of morphine was similar to that of either of the two used singly(P>0.05).These facts indicate that thc analgesic effect of SP activated by PAG was mediated through the increase of cerebral met-cnkcphalin con- tent,and there was a synergic effect between SP and elcctroacupuncturc.

关 键 词：ANALGESIA clectroacupuncture MET-ENKEPHALIN substance P PAIN THRESHOLD areas in BRAIN 

分 类 号：R[医药卫生]