Histochemical determination of lactate dehydrogenase activity in rat lens; influence of different parameters

Abstract

ABSTRACT.Purpose: 1. To optimize a histochemical technique for the determination of lactate dehydrogenase activity in rat lens. 2. To determine the distribution of lactate dehydrogenase activity within the lens. 3. To analyse different components of variation in the method. Methods: A total of 24 six-week-old Sprague-Dawley rats were used. Cryosections of whole eyes were incubated with different media. The influence of incubation time, pH, the concentration of dye, lactate, nicotinamide dinucleotide, phenazine methosulfate, sodium azide, hydrazine and polyvinyl alcohol on the enzyme histochemical reaction was investigated. The staining reactant was nitrobluetetrazolium and the staining density was measured with a microscopebased photometer. Results: The lactate dehydrogenase activity was highest in the epithelium, followed by the nucleus, the anterior cortex, and the posterior cortex. The three largest components of variation in the analyses were rats, sections (including variation in section thickness) and density measurements (including variation within the different regions). Conclusion:The composition of the final incubation medium for the detection of lactate dehydrogenase activity in rat lens are similar to that shown for other tissues. Lactate dehydrogenase activity varies in different regions of the lens.