Hyperbaric Oxygen in vivo Accelerates the Loss of Cytoskeletal Proteins and MIP26 in Guinea Pig Lens Nucleus

The Effects of Hyperbaric Oxygen on the Crystallins of Cultured Rabbit Lenses: a Possible Catalytic Role for Copper

“…This result, which has been reported previously (Giblin et al, 1988), re¯ects the relatively low ability of the lens nucleus to regenerate GSH from GSSG as a result of low activities of key antioxidant enzymes (Giblin and Reddy, 1980;Giblin, Nies and Reddy, 1981). Thus, the lens nucleus is more susceptible to oxidative damage than the cortex, as has also been demonstrated with use of an in vivo HBO model Padgaonkar et al, 1999;Borchman et al, 2000).…”

“…Similar results have been obtained in experimental studies conducted with mice (Schocket et al, 1972) and guinea pigs Padgaonkar et al, 1999;Borchman et al, 2000). It is known that exposure to HBO in vivo can signi®cantly increase the levels of protein thiol mixed disul®des and protein disul®de (PSSP), primarily in the nucleus, and can accelerate the age-related loss of soluble protein, cytoskeletal proteins and MIP26 in the central lens region.…”

“…The present study indicated that any protective ability of the lens crystallins against physiological concentrations of copper was apparently overcome by elevated levels of oxygen. Oxidative effects that have been observed in human nuclear cataracts (Truscott and Augusteyn, 1977;Fu et al, 1998) and in vivo experimental models Padgaonkar et al, 1999;Borchman et al, 2000) can best be explained by a mechanism of metal-catalysed autoxidation (Garland, 1990). Copper bound to glycated and ascorbylated lens crystallins has been reported to possess signi®cant redox activity (Saxena et al, 1999(Saxena et al, , 2000.…”

Fourier Analysis of Cytoplasmic Texture in Nuclear Fiber Cells from Transparent and Cataractous Human and Animal Lenses

“…The autocorrelation background patterns correlate well with the degree of nuclear opaci®cation. The results of these cytoplasmic analysis techniques correspond with the gross examination of the lenses: the normal lenses were transparent, the HBO-treated guinea pig showed a small amount of high-angle light scattering by slit lamp (however, the lenses were still transparent (Padgaonkar et al, 1999)), and the OXYS rat and diabetic canine lenses were totally opaque (Taylor et al, 1997;Costello et al, 2000;Marsili et al, 2000).…”

Point: A Critical Appraisal of the Lens Circulation Model—An Experimental Paradigm for Understanding the Maintenance of Lens Transparency?

“…31 In guinea pigs given prolonged HBO treatments, the level of GSH in the nucleus became nearly 10 times lower than that in the cortex, and GSH-and cysteine-protein-mixed disulfides in the nucleus increased dramatically. 25,30 It has been suggested that the decline in GSH concentration that occurs in the nucleus of the human lens with increasing age is caused by a barrier to diffusion from the periphery to the center of the lens. 32 The decline in GSH and the resulting increase in GSSG leads to oxidation of cysteine and methionine residues in proteins, a hallmark of age-related nuclear cataracts.…”