Effect of pH on the bioenergetics of perfused porcine lenses.

Abstract

Extracellular and intracellular pH has been shown to be an important physiological variable in many biological systems. However, studies on the effect of pH on the metabolic status of the mammalian lens have been few. It has been shown previously that a change in perfusate pH has a significant effect on the lens weight, ion transport, opacification and membrane potential. In this study we show that the bioenergetic status of the perfused pig lens, as assessed by 31P-NMR spectroscopy, is critically dependent on the pH of the bathing medium. At pH's of 7.6 and above, these perfused lenses maintained their nucleotide triphosphates concentrations steady for up to 4 days. In contrast, lenses perfused with identical media at pH 7.0, rapidly lost their nucleotide triphosphates. Our findings suggest that the pH of the extracellular pH may be an important parameter in maintaining the functional competence of the lens.