The Topography Studies On Müller Cells In The Normal Rat Retina And Morphological Changes Of Müller Cells Of The Diabetic Rat

Objective: 1. To observe the distribution characteristics of Müller cells of normal rat retina in different levels and quadrants of the retina. To explore the function of the Müller cells by means of morphology. 2.To study the morphological changes and the malfunction of the Müller cell in streptozotocin (STZ) diabetic rats to investigate the pathological mechanism of the Müller cell in the effect on the course of diabetic retinopathy.Method: 1,To observe the fundus by ophthalmoscopy, and to study the morphology of the Müller cell of the normal retina by means of light microscopy and transmission electron microscope(TEM), respectively.2,Diabetes was induced in rats by intraperitoneal injection of 75 mg/kg of streptozotocin (STZ). Age-matched rats raised under similar conditions served as control. By the 4 weeks,8 weeks,12 weeks,24 weeks of diabetes, we observed the morphological changes of the retina.,especially the Müller cell, through the technique of ophthalmoscopy, light microscopy and transmission electron microscope(TEM).Result: 1,Müller cells have a wide distribution in the inner plexiform layer,the ganglion cell layer and optic nerve fibre layer,the inner nuclear layer,while in the outer plexiform layer, the outer nuclear layer and the photoreceptor cell layer there are less distribution. In every layer of retina, the mitochondrion of Müller cells shows a tendency that the distribution of it gradually turn wider from photoreceptor cell layer to ganglion cell layer and optic nerve fibre layer, which is identical to what Müller cells do. 2,Müller cells have a relatively homogeneous distribution in every quadrants of retina and the cells relatively have similar shapes and sizes, without apparent differences. 3,Four weeks after the diabetic rats grew up, there are changes in the process of Müller cells and inner plexiform layer,ganglion cell layer and optic nerve fibre layer. The changes are that in the cell body, the mitochondrion become edematous and the crest become short and disappear. As the disease course of debate lengthens, the pathologic change of Müller cells increasingly turn worse. The changes are the increase of the edematous mitochondrion, the fragmentation of crest and the increase of physalides. After 12 weeks the shape of retina full-thickness Müller cells and nervous cells have changed. 4,In each quadrant of retina, the time that Müller cells take morphology changes in the processes of different diabetes is relatively similar. And in the process of a certain diabetes, the changes of Müller cells morphology are similar. With the extension of duration of diabetes, the cell body and process of Müller cells swells gradually, the number of mitochondria decreasing, the degree of vacuolization enhancing, and the organelles reducing.Conclusion: 1,Müller cells do not distribute uniformly in each layer of retinas, with a wide distribution in the inner plexiform layer,the ganglion cell layer and optic nerve fibre layer,therefore, their effect on each layer of retina varies. 2,Müller cells distribute relatively uniformly in each quadrant of retinas, which is the result of the functions of Müller cells and they are widely related to the neurons of retina. 3,Müller cells, the important glial cells, not only are the stents of retinas, but have the functions of nutrition, support, insulation, and protection to the neurons of retina. 4,The changes of structural functions taking place in diabetes probably affect the energy supply of the neurons of retina and the steadiness of microenvironment, enhancing damages to structures and functions of the neurons of retina. 5,In the case of diabetes, Müller cells do not distribute uniformly in each layer of retina and the time that Müller cells take configuration changes is not the same, happening first in the inner plexiform layer, the ganglion cell layer, and the optic nerve fiber layer and affecting firstly the ganglion cells and then other neurons of retinas. 6.,In each quadrant of retina, the time and the features that Müller cells take morphology changes in diabetes are relatively similar.