Lens cation transport and permeability changes following exposure to hydrogen peroxide.
Exposure of the rabbit lens, in vitro, to 10(-3) M-hydrogen peroxide resulted in an increase of the lens sodium, calcium and water content together with a decrease of the lens potassium content. No such changes were observed in the presence of 10(-4) or 10(-5) M-hydrogen peroxide. 10(-3) M-hydrogen peroxide was observed to diminish 86Rb uptake by 32% and to reduce the lens Na+-, K+-ATPase activity by 37%. The lens potential remained ouabain-sensitive after peroxide treatment. These findings suggest that only partial inhibition of the lens sodium pump takes place in the presence of 10(-3) M-hydrogen peroxide. Lens depolarization, increased lens conductance and an increase rate of 86Rb efflux were also observed upon exposure of the lens to 10(-3) M-hydrogen peroxide. Such alterations of 86Rb efflux and electrophysiological parameters indicate that hydrogen peroxide changes the passive permeability of lens membranes.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001834:Body Water / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D004594:Electrophysiology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D066298:In Vitro Techniques; D007908:Lens, Crystalline / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D011817:Rabbits; D011868:Radioisotopes; D012413:Rubidium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013997:Time Factors
D011868:Radioisotopes; D012964:Sodium; D006861:Hydrogen Peroxide; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium; D011188:Potassium; D002118:Calcium