Changes in tubular membrane glycosylation in diabetic, insulin and thyroxin treated rat kidneys

The effect of insulin, thyroxine and alloxan induced diabetes has been studied on brush border membrane glycosylation in rat kidneys. Expressed on dry weight basis, the membrane protein was elevated in insulin, thyroxine and diabetic membranes compared to the control group. Sialic acid content of the membranes was significantly reduced in insulin and thyroxine injected animals whereas fucose level was unaffected under these conditions. Brush border fucose content was significantly reduced in diabetic animals but sialic acid content was unaffected. Membrane hexose and hexosamines levels were unaltered by hormone treatments, but in diabetic rats hexosamine level was significantly reduced. The binding of radiolabelled UEA, WGA, PNA to purified brush borders corroborated changes in membrane saccharides. These findings suggest the role of hormones in membrane glycosylation of rat kidney tubules.