The Relationship Between Epression Of MMP-9 And Presyrinx State Of Experimental Syringomyelia In Rabbits

objective: Syringomyelia is a kind of chronic disease.It'smechanism is still incompletely clear, and for this reason thecause of disease become the focus to dispute. Presyrinx state is anew concept that was put forward in study mechanism ofSyringomyelia in the last few years. because it can indicate theearlier period expression of syringomyelia, research of thepresyrinx state have great use in preventing and treatingsyringomyelia. Our experiment showed: presyrinx state is a kind ofchanges for lack in blood. This kind of swollen is asogenicedema .the main cause is disruption of the blood-brain barrierand abnormal vascular permeability. Matrix metallo-proteinase-9 can degrades gelatin ,collagen Ⅳ, Ⅴ; elastin;virtronectin; myelin basic protein; and other subtrates. as to this,it can disrupt the blood – brain barrier and increase the vascularpermeability. so we think MMP-9 may plays an important rolein presyrinx state. doxycyline is artificially synthized inhabitorof MMP-9. it can inhabit MMP-9 activity. This experimenttarget to investigate the role and mechanism of MMP-9 inthe formation of presyrinx state of experimental syringomyelia──────────────────────────────────────── 6英 文 摘 要in rabbits,and supply the basis to the therapy and prevention tosyringomyelia. We estimate the degree of the spinal cord edemaand observed its development tendency.In the same time , theMMP-9 expression intensity in spinal cord was determined bywesternblot and immunohistochemistry,moreover,we applieddoxycyline to interfere the MMP-9 activity. Method: 96 Chinese white rabbits, weight 1.5-2 kg, isdivided randomly into fuor groups: Kaolin group(30 rabbits),the group treated with doxycycline (30 rabbits), physiologicalsaline group(30 rabbits) and contral group(6 rabbits). Underketamine anesthesia (30 mgs/ kg),0.6ml of 25% kaolin solutionwas injected into the cisterna magna after 0.6ml of cereberalspinal fliud was withdraw slowly from the cistern, in all rabbitsof the kaolin group and doxycycline group,while 0.6ml of 37℃physiological saline was injected into the cistern in those ofsaline group; the doxycycline (25mg/kg.d) after the operationwas applied for doxycycline group. At first, third, seventh,tenth, forteenth day after kaolin injection, the rabbits selectedrandomly from every group were anaethetized again. All theanimals were killed by trasecting at junction of cervico-thorciccord, then the brains and cervico cords were moved wholly andquicly, 4mm cervico cord were cut from C1-2 segement,the wetweight(W) was obtained with electronic balance(0.0001g) afterclearing off carefully the arachnoid, kaolin deposition andwater from surface. The dry weigh(D) was scaled after roastingfor 24 hours in 110℃ thermostatic baker .Water content of──────────────────────────────────────── 7英 文 摘 要spinal cord (%) can be obtained with the formula:watercontent(%)=(W-D)/W×100.The spcimens of C2-3 were fixedin 4% formaldehydum polymeridatum for 48 hours, thenembeded in the paraffin . H﹠E staining and imumuno-histochemistry were completed to the section. Take thesection C3-4 a specimen to put into the liquid nitrogen for 2minuteses quickly,then keep it in -70 ℃ refrigerators. Westernblot measureses the expression of MMP-9 activity. Theexpression of MMP-9 at different time pionts was comparedwith edema level of spinal cord at corresponding time point,while both of the development tendencys were observed. Result: All animals of kaolin group had showndepressd,anorexia from the first to third day after acupuncture,most severely during the seventh to the fourteenth day inaddition to having the slight paralysis in this period; thesesymptoms were remissive after 2 weeks. The animals ofdoxycycline group had shown depressd,anorexia from the fi...