Details

Autor(en) / Beteiligte

• Mitton, Kenneth P.
• Hess, John L.
• Bunce, G. Edwin

Titel

Free amino acids reflect impact of selenite-dependent stress on primary metabolism in rat lens

Ist Teil von

• Current eye research, 1997-10, Vol.16 (10), p.997-1005

Ort / Verlag

England: Informa UK Ltd

Erscheinungsjahr

1997

Quelle

MEDLINE

Beschreibungen/Notizen

• PURPOSE. A decrease in phase separation temperature, prior to nuclear cataract, has been correlated with elevated free amino acid content. Hence, we determined how selenite-induced stress alters free amino acid pools in the rat lens, following a single subcutaneous dose of sodium selenite (30 nmol g -1 body weight) in 10- to 14-day-old Sprague Dawley rats. RESULTS. Oxidative stress was evident in lenses 24 h after rats were treated with selenite. Glutathione content was decreased by 60% in the lens cortex and nucleus; the flux of glucose through the pentose phosphate pathway was increased; and glycerol-3-phosphate content was elevated. Amino acid transport, evaluated as 14 C-cycloleucine uptake, was not altered, although 14 C-glutamine was oxidized at a slower rate. Lenses from treated animals displayed, among the free amino acids, increased glutamine, proline, serine, glycine and the branched chain amino acids, while aspartate, glutamate, and taurine were less. CONCLUSIONS. A systemic delivery of sodium selenite caused oxidative stress in the rat lens. Direct effects on primary metabolism altered free amino acid pools that may contribute to transient and permanent changes in lens transparency.