The lens's response to exogenous hydrogen peroxide.
Rat lenses treated with greater than 0.06 mM hydrogen peroxide (HP) appeared to sustain epithelial damage, particularly a loss of enzymes including hexokinase, which controls the supply of glucose-6-phosphate. This may account for the lower level of hexose monophosphate shunt activation observed in these lenses. Other alterations include a decrease of lactate production and disturbance to ionic balance. These changes occurred despite HP removal by glutathione reductase/peroxidase system, catalase and other mechanisms. This suggests an inherent weakness for the lens to resist stresses from high levels of HP. Further, competition for NADPH between aldose reductase and glutathione reductase apparently affects the lens's ability to detoxify HP. This implies a role for oxidation in diabetic cataractogenesis.
Cheng
H M
HM
Howe Laboratory of Ophthalmology, Harvard Medical School, Boston, Mass. 02114.
D000818:Animals; D006861:Hydrogen Peroxide / Q000493:pharmacokinetics / Q000494:pharmacology*; D008658:Inactivation, Metabolic; D007908:Lens, Crystalline / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010427:Pentose Phosphate Pathway; D051381:Rats; D011919:Rats, Inbred Strains
D006861:Hydrogen Peroxide