Comparative study of superoxide dismutase in normal and hereditary cataract (UPL) rats

In the present study, the levels of SOD activity and Cu, Zn-SOD mRNA in the brain, kidney, liver and eye of normal and Upjohn Pharmaceutics Limited (UPL) rats, a new hereditary cataract model derived from Sprague-Dawley rats, were measured. Although the levels of SOD activity in the eye and brain of UPL rats were significantly decreased compared with those of normal rats 3 and 5 weeks after birth, the levels of SOD activities in the kidney and liver were the same in both groups. The levels of Cu, Zn-SOD mRNA in kidney and liver of UPL rats were the same as those of normal controls. The level of Cu, Zn-SOD mRNA in the brain of normal rats 5 weeks after birth was about twofold greater than that of UPL, and that in the eye of UPL rats 3 weeks after birth was significantly decreased compared with that of normal controls. The sequences of cDNA encoding Cu, Zn-SOD and the sequences of the regulatory region of the Cu, Zn-SOD gene were confirmed to be the same in normal and UPL rats. These results indicated that the decreases in levels of SOD activity and Cu, Zn-SOD mRNA in the brain and eye of UPL rat were not due to mutation of the genomic Cu, Zn-SOD gene in UPL rats or differences in the sequence of the regulatory region of the Cu, Zn-SOD gene between normal and UPL rats.