实验性IgA肾小球肾炎——抗原的电荷在肾炎发病机理中的意义

Experimental IgA Glomerulonephritis :The Effect of Charges of Antigen on the Pathogenesis of Glomerulonephritis

本文选用阳、阴离子化右旋糖酐作抗原,分别诱发小鼠IgA肾小球肾炎。用显微分光光度计测定肾小球内IgA荧光强度,并结合形态学观察。结果显示阳离子组荧光强度显著高于阴离子组(P<0.01)。电镜下,两实验组均呈现肾小球系膜基质增生、细胞轻度增生及基质内电子致密物沉积;阳离子组基底膜增厚,其上沉积物及足突融合更为明显。显示抗原所带电荷可影响肾炎病变程度及其定位,而阳离子化比阴离子化物质对肾小球肾炎病变形态发生的影响更为显著。且阳离子化右旋糖酐引起的IgA肾炎属于原位免疫复合物性肾小球肾炎。

Cationic dextran (DEAE-dextran) and anionic dextran (Sulfate-dext-ran) were used as antigens respectively to induce immunocomplex glomerulonephritis in mice.The mean relative brilliances of IgA immunofluorescence in glomeruli were measured by scanning-microspc-ctrophotometer.The renal cortexes were also observed under transmission and scanning electron microscope.The results showed:1.The relative brilliance of IgA immunofluorescence in glomeruli in both cation group and anion group was stronger than that in controls.The difference was statistically highly significant (P<0.01),and it was stronger in cation group than in anion group (P<0.01); 2.Increase of mesangical matrix,slight proliferation of mesangical cells and dense deposits in mesangical matrix were noted under electron microscope both in cation and anion groups.However,thickened basement membrane,dense deposits in basement membrane and the fusion of the podocytic processes were easily observed in cation group than in anion group.The results indicate that the electronchemical effect of the charges of the antigen and those of glomerular filtration membrane may affect the extent and site of immunocomplex deposits in glomeruli.Furthermore,the substances with cation exert more striking effect on morphological changes in patho-genesis of nephritis than those with anion.