Acute effect of ethanol on lens cation homeostasis.
This study examined the effect of ethanol on the calcium homeostasis of the bovine lens. After acute exposure of the whole lens to physiologically related ethanol concentration, the calcium content of the lens cortex increased from 0.345 +/- 0.075 to 0.476 +/- 0.047 micromol/g (p < 0.05). In contrast, other cation levels such as sodium, potassium, and magnesium did not change. In the study of the lens calcium transport, ethanol caused an increase in the calcium permeability of the lens lipid membrane by about 12% at 30 mM ethanol. Ethanol did not alter the calcium pump activity at ethanol concentration up to 400 mM. Above 600 mM ethanol, the calcium pump was almost completely inhibited. It has been suggested that moderate to heavy alcohol consumption is a risk factor for cataracts. This study indicates that acute ethanol exposure can cause a loss in the lens calcium homeostasis, which maybe one of the cellular mechanisms to contribute to the cataract development in the alcoholic individual.
Zeng
J
J
Department of Ophthalmology & Visual Sciences, Kentucky Lions Eye Research Institute, University of Louisville School of Medicine, 40292, USA.
Borchman
D
D
Paterson
C A
CA
D000818:Animals; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000187:drug effects; D002412:Cations; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D005123:Eye / Q000187:drug effects; D016257:Fura-2 / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects*; D007904:Lens Cortex, Crystalline / Q000187:drug effects*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D002412:Cations; D000431:Ethanol; D012964:Sodium; D000252:Calcium-Transporting ATPases; D011188:Potassium; D002118:Calcium; D016257:Fura-2