Changes in components of fast axonally transported proteins in the optic nerves of diabetic rabbits.

Proteins synthesized in retinal ganglion cells were labeled with 35S-methionine or 3H-leucine to the vitreous cavity, and the components of fast axonally transported proteins were studied in 20 nerves of 10 normal rabbits and 34 nerves of 17 alloxan-induced diabetic rabbits. Proteins in the optic nerves were separated by SDS-polyacrylamide gel electrophoresis, and axonally transferred proteins were studied by fluorography. In diabetic animals, the axonally transported radioactivity was one-fifth that of the controls. In the fluorographic spectrum of 35S-methionine-labeled proteins, relative proportion of 120kDalton(D)-proteins were increased by 43%, and 29kD proteins were decreased by 65% in diabetic rabbits. Relative proportion of other proteins, such as 24k, 36k, 68k, 150k and 180kD, were the same in control and diabetic rabbits. The quantitative reduction and change in spectrum of fast axonally transported proteins are compatible with the vulnerability and dysfunctions of nerve fibers in diabetic patients.