| PrefaceRecently, the incidence rate of the chemical injuries is increasing year by year. Among all the chemical injuries , alkali injury is the most de-vastating. According to many researches, Matrix metaloproteinases (MMP)may have the important effect on corneal stromal ulcer during the process of incidence and progression of which resulted from alkali- burn. Researchers have been trying to look for the ideal inside and outside the tissue inhibitor of matrix metaloproteinases (TIMP) to prevent the sequela of alkali burn, until now they have made great progress. But they have no definite conclusion of what period is the high peak of the MMP and whether the content of MMP and the dissolving of cornea occurent synchronously and what period is the best time to use TIMP.The purpose of this experiment is to observe the expression of the MMP-1 in the cornea and its inhibitor in the different period of the development of alkali burn by establishing of the rat corneal alkali-bum model and discover their functions during the dissolving of cornea after the alkali bums in order to supply the necessarytheory for the reasonable using of TIMP to prevent corneal ulcerationExperimental materialsWe choose 35 healthy SD rats as experimental animals. The main reagents and equipments are rabbit polyclonal anti-rat MMP-1,goat polyclonal anti-rat TIMP-1, peroxide enzymal goat anti-rabbit IgG, rabbit anti-goat IgG and SP reagent box. Computer analysis system of immunohistochemitry.MethodsExperimental group was established rat corneal alkali- burn model. The rats were killed after they got alkali- burn. The cornea was taken out of the body rapidly and tested in HE and Immunohistochemical dyeing. The change and expression of MMP-1 and TIMP-1 were tested during different period of alkali-burn. Observing the changes of cornea by fluorescence sodium dyeing simultaneously.ResultsNo MMP-1 and its inhibitor's expression were found in the normal rat cornea. In the 1st day of the tested rat suffering from alkali-burn ,cornea epithelium got lost, stromal fibre got swell and fat . At the edge of cornea. Between the 4th day and 7th day, stromal ulceration got the high peak, cornea dissolving got worseand many of was found. On the 14th day ulceration got the high peak, cornea dissolving got worse and the inflammatory cell decreased. From the 21st day and 28th day, ulceration was observed, the con juction of stromal fibre was founded. By immunohistoche mistry, increased expression of MMP-1 was found on the 1st day ,being highest on the 14th day, then decreased slowly, however it was still higher than the normal. TIMP-1 expressed in the early phrase. But later,its activity droped step by step. TIMP-1 reached the lowest level on the 14th day. After that, it began to increase and being the highest levels seen on the 21th day.DiscussionTo great extent, proteinases'effect resulted in the incidence of cornea ulceration after alkali injuries. Among most of the proteinases, MMPs is the main one. MMPs is the Zn-depended enzymal family. It can be devided into 4 groups according to its struction. Among them, MMP-1 plays very important role during the process of incidence and progression of cornea! ulceration after alkaline burns. TIMPs is the later-founded factor family with multifunction. Four members have been found until now. The later research showed that HMP-1 is the inhibitor of MMP-1 and TIMP-1 can join with MMP-1 in the proportion of 1:1. TIMP-1 can inhibit the function of MMP-1, by which it plays very important role in keeping the stability of ECM. The test of the expression of MMP-1 and its inhibitor in the alkali-bum cornea ishelpful to research the reason of corneal alkali burns.By Immunohistochemitry and analysis system of pathologic picture, the relative studies showed the different expressions of MMP-1 and TIMP-1 in different period and they have simultaneous incidence with comeal dissolving. The studies of TIMP-1 can provide a new way to prevent the incidence of comeal ulceration after al...
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