mRNA levels for calpain II in normal, aging and cataractous rat lenses were measured by quantitative RT-PCR using an competitive RNA standard.Results indicated that mRNA for calpain II was 4-24 times higher in young rat lens than in age-matched rat liver, kidney, lung and brain and was 5 times higher than young human lens. Calpain II mRNA in rat lens decreased with age. Early-stage selenite cataract showed a 2-fold increase; while nuclear cataract showed a 64% of decrease in calpain II mRNA. In contrast, mRNA levels forp-actin, GAPDH, and bA4 remained constant. Conclusions: These are the first quantitative data to show that the mRNA levels for calpain II in young rat lens are higher than in age-matched other rat tissues and can change during normal maturation and cataract formation.These data help explain the high activity of calpain II and susceptibility to a variety of catarats in young rat lens, loss of cataract susceptibility with age, and low calpain activity in human lens. Fairly rapid changes in mRNA may be an additional regulator of calpain II activity in rat lens, (supported by EY05786 and Research to Prevent Blindness).
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology