[A study of coloring in human lens nucleus--association of four inorganic elements and dielectric behavior with nuclear color].

: We classified senile cataractous lenses before surgery into five grades on the basis of their nuclear color and analyzed the extracted nuclei on wet weight, water content (weight %), inorganic element content (sodium, potassium, calcium and magnesium), and dielectric behavior. With increase in the grade, water content (p < 0.01) and potassium content (p < 0.05) significantly decreased, and wet weight (p < 0.01) and sodium (p < 0.05), calcium (p < 0.01) and magnesium (p < 0.001) content significantly increased. In dielectric behavior, limiting conductivity at low frequencies significantly decreased with increase in the grade (p < 0.05), and limiting permittivity at high frequencies showed a trend to decrease, but it was not significant (p = 0.052). These results indicate that changes in water content and in inorganic element content are associated with advancement in color grade, suggesting a close relation between the color grade and the membrane functions of lens fibers. In the nuclei with high color grade, we concluded that part of the active transport systems of the fiber membranes was damaged, although the electrical barrier of the membranes was retained.