Relative Contents of Sodium, Potassium, Water and Dry Matter in Human Senile Cataractous Lenses in Relation to Anterior Capsular/Subcapsular Opacity

Abstract

In 49 human senile cataractous lenses the sodium and potassium concentrations of the lens water as well as the water and dry weight percentages were examined. It was found justifiable to classify the lenses into three categories on the basis of correlated biomicroscopic and biochemical findings: 1. Immature cataractous lenses without anterior capsular/subcapsular opacity (ac-sco) were characterized by low CNaL+, high CKL+ and low sums of CNaL++CKL+. 2. Immature cataractous lenses with ac-sco were characterized by intermediate value of CNaL+ and CKL+, as well as high sums of CNAL++CKL+. 3. Totally opaque lenses (these lenses had 80-100% of ac-sco) were characterized by high CNaL+, low CKL+, high sums of CNaL++CKL+, high water, and low dry weight percentages. It was found that in immature cataractous lenses increasing extension of ac-sco was correlated to increasing CNAL+ and increasing ratios of CNAL+/CNAA+ as well as to decreasing CKL+ and decreasing ratios of CKL+/CKA+. The sums of CNaL++CKA+ increased. There was a correlation of the extent of ac=sco to the water and dry weight percentages of the immature senile cataractous lenses with ac-sco, viz. a negative correlation for water and a positive one for the dry weight. However, these latter two correlations may be due to chance significances, the level of significance being only greater than P greater than 0.02 in both instances. Lenses which were estimated to have larger than or equal to 30% of ac-sco were found to be more opaque than lenses with less than or equal to 25% of ac-sco.

Variations of Lens Thickness in Relation to Biomicroscopic Types of Human Senile Cataract

“…Later it has been suggested that proteins of low molecular weight leak from the lens to the aqueous during senile cataractogenesis (Mach 1963;Charlton k van Heyningen 1968;van Heyningen 1972). In accordance with this, Klauber 8: Bruun Laursen (1977) found low dry weight (= protein) percentages in totally opaque lenses. Since such lenses are small as compared with e. g. the thicker immature cataractous lenses, totally opaque lenses obviously contain less protein than do thick immature cataractous lenses.…”

HUMAN SENILE CATARACT AND Na‐K ATP'ase ACTIVITY IN THE ANTERIOR LENS STRUCTURES

“…5) The central anterior lens structures were chosen for Na-K ATPase activity assay because cation transport appears to be most active here (Becker & Cotlier 1962). The C,,+/C,+ ratio of ACSCO lenses increases with increasing extent of ACSCO (Klauber & Bruun Laursen 1977). As indicated by Duncan (1973) such a change may be due to 1) decreasing lenticular Na-K ATPase activity or 2) increasing permeability of the ion-restricting lens membranes.…”

“…In addition, the blank tubes contained 1 mM ouabain. The protein concentration was approximately 0.3-0.6% (calculated from disc weights and protein percentage -Klauber & Bruun Laursen 1977). Furthermore, in 25 lenses the activity of the Na-K ATP'ase in the anterior structures of each individual lens was determined at the following C,,+/C,+ ratios in the assay medium: 6/150,36/120,8l/75 meqil.…”

“…Fig. 1 Laursen 1977). Furthermore, in 25 lenses the activity of the Na-K ATP'ase in the anterior structures of each individual lens was determined at the following C,,+/C,+ ratios in the assay medium: 6/150,36/120,8l/75 meqil.…”

“…The aim of the present study was to examine a possible correlation between the Na-K ATP'ase activity in the anterior lens structures and the extent of the biomicroscopically visible anterior capsular/subcapsular opacity (AC SCO) (Bruun Laursen 1976), previously found to be an indicator of increasing C,,+/C,+ ratio in the lens water (Klauber & Bruun Laursen 1977). T h e study was carried out by a) investigating the histochemical location of ATP'ase reaction products in the anterior part of the lens, b) biochemical analysis of the enzyme activity in the anterior lens tissue and c) examining the influence of changes in the C,,+/C,+ ratio o n the activity of the enzyme system.…”