Lactate dehydrogenase activity and its isoenzymes in concentric layers of adult bovine and calf lenses

Abstract

The activity of lactate dehydrogenase (LDH) and its isoenzyme pattern were studied in four concentric layers of adult bovine and calf lenses. In both groups the specific activity of the total LDH diminished progressively toward the internal nuclear layer; the decrease was greater in the adult lenses. The enzyme activities in the cortical layers of the calf lens were lower than in the adult lens, but in the inner nuclear layers, the opposite was found. All of the 5 LDH isoenzymes were found in each layer. In both groups of animals the LDH1 isoenzyme prevailed, followed by LDH2. No differences were found in the percentage of each isoenzyme in the different lens layers. The differences in the activitie(s) of LDH found may be due to post-translational or post-synthetic modifications which may occur during the aging process.

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

“…Therefore, the LDH molecules or their local environment have the same degree of post-synthetic changes. In some other species or strains, however, the LDH activity in the nucleus has been shown to be lower than in the cortex (Kaskel et al 1978, Ohrloff 1978, Sempol et al 1987, Kojima 1992. Thus, there are both age and species dependent differences between cortical and nuclear activities.…”

“…The enzyme activity in a young lens nucleus should then be proportional to the enzyme concentration. As the lens ages, the oldest enzyme molecules, those in the nucleus, will exhibit a lower activity (Ohrloff 1978, Ohrloff et al 1980, Dovrat et al 1986, Sempol et al 1987.…”