The Study Of Collagen Fiber In Iris Extracellular Of Primary Angle Closure Glaucoma

Objective To study the mechanism of the primary angle-closure glaucoma (PACG), Just because there is a large of collgen fibrill in Extracellular, organ and tissue have special structure, function and property of mechanics , for instance extension, elasticity. Learning the content and the type of collagen fibrill is the premise which study mechanical property of iris . In the course of PACG attack, the iris extension is not allowned ignorance. To discuss whether or not the change of iris extension in primary angle closure glaucoma (PACG)and the foundation in histology, molecular biology.Methods 1 Take 29 sample of PACG iris root (44±9. 5years old)and 11 age-suited trauma eye iris root (41.5 ± 9.9 years old, injury time within 2 hours) into 4% formaldehyde , fixation for 4 hours and 48 hours differently, embedded in paraffine and sliced to 2 micron .Carry out staining of HE, Masson, Weigert, in situ hybridization and immunohistochemistry study.2 Take age-suited 4 specimen of the PACG iris root and trauma eye iris root respectively into glutaraldehyde, fixation for 48 hours. Observe the change of ultrastructure between two groups by transmission electron microscopy.3 Take 20 specimen of the primary angle closure glaucoma iris root and age-suited 9 trauma eye iris root into succusnitrogen immediately for reverse transcription-polymerase chain reaction.Results 1 There is a large amount of vessel and collagen fibrilin iris stroma in two grogps .Pigment cell and stromal cell scattered within stroma. No elastin in iris stroma.2 Amount of melanocyte , fibroblast , vessel, and few obesity cell were observed in iris stroma by transmission electron microscopy. In normal eye, Large number of collagen fibril are parallelly distributed . Rough endoplasmic reticulum of fibroblast is abundant , the density of mitochondrion stroma is clear and Golgic complex is developmented.In primary angle-closure glaucoma, the number of collagen fibril in iris stroma is decreased and the structure of collagen fibril is blurred . Rough endoplasmic reticulum of fibroblastics is decreased , the density of mitochondrion stroma is increased.3 The immunohistochemistry study show that collagen type I> IK III distribute in iris stroma and blood vessel wall. Type IV collagen distribute in basal membrane of pigment cell and endothelium of vessel. The content of collagen type I is abundant in four types . collagen type I was expressed lower in PACG. there was no difference in content of type IK III > IV collagen.4 Collagen type I, IK III mRNA positive cells , affirmed fibroblast, are located in iris stroma by in situ hybridization. Part of positive stroma cell in stroma are not affirmed .The amount of type I mRNA positive cells is lower in primary angle-closure glaucoma, there was no difference of collagen type IK III in two groups.5 The electrophoresis band of collagen type I > IK 11 ImRNA arranged from 250bp to lOOObp. The expression of collagen type I mRNA is lower in PACG by reverse transcription-polymerase chain reaction, there was no difference of collagen type IK III expression in two groups.Conclusions The study of quality, quantity, location of collagenfiber in iris stroma shows that :1 Type Is IK IIK IV collagen were expressed in iris stroma . The content of collagen, from high to low, is type I ^ II> UK IV. Which collgen type I was expressed decreased in PACG iris .Because of the powerful tension and abundant content of type I in stroma, The extension of iris in PACG is lower . The iris root is easily move forward and block angle of anterior chamber under same pressure of aqueous humor.2 Collagen type I> II> IIImRNA positive cells , affirmed fibroblast, are located in iris stroma .Part of stroma cell represented positive staining. The study show that the source of secretion is not fibroblast entirely .Which the amount of type I mRNA positive cells is lower in PACG indicates that the function of cell is weak.3 The expression of collagen type I mRNA is lower in PACG by reverse transcription-polymerase chain reaction and there is no difference of collagen type IK III in two groups .Which indicates that the synthesize of collagen type I is lower. Study above all shows that the extension of iris is decreased in PACG . The transmogrification of PACG iris , Compare with nomal iris, takeplaced easily and move forward passively under certain intraocular pressure and easily block angle of anterior chamber.4 Rusults above all indicates the gene that decided the trait of collagen may be relative to PACG...