Lactate dehydrogenase of concentric zones of human senile cataracts and calf lenses produced by ultrasound.

Cataractous lenses from men and women averaging 77.7 years of age were sonicated for intervals of 10 min with 0.85% saline under cooling in a laboratory sonicator, followed by centrifugation. The respective supernatants were analyzed for LDH and the weights of the zonal portions obtained by difference. The initial fraction averaged 60 and 47% in solids and LDH, respectively, with decreasing contents to the final harder core residue. The procedures were also applied to calf lenses. Much shorter sonication periods and stepwise increases in wattage from one fraction to the next were also investigated. The calf lens displayed higher LDH activity/mg at settings of 6-8 W in contrast to the cataracts, the initial fraction containing 80% of the enzyme activity and the solids; the values were far lower at settings of 1-3 W. As compared to the sonicated outer layer fractions, the calf nuclear portions showed small but significant decrements in the isoenzymes, LDH-1 and LDH-2, and increases in LDH-4 and LDH-5, possibly indicative of heightened anaerobiasis.