Glucose metabolism and protein synthesis in stratified squamous epithelia from young and old mice

Glucose metabolism in regionally distinct epidermis and oral epithelia of young adult and aged mice was studied using 5-3H glucose and differentially labelled 14C-glucose. The results obtained with 3H-glucose indicate there is active utilization of glucose by all the epithelia examined. However, an enhanced utilization of glucose was observed in old ear epidermis when compared to that in young mice. The measurements of respiratory 14CO2 in the young and old epidermis indicated that aerobic glycolysis was significantly greater in ear epidermis and buccal epithelium from old than from young mice. Pentose phosphate activity was significantly reduced in palate epithelium from old animals when compared with that of young animals. Incorporation of radioactively labelled leucine and histidine revealed some regional differences between the epithelia examined. However, no age-associated differences were observed in any of the tissues. It is concluded that the observed metabolic changes reflect regionally specific adaptations to local factors rather than representing a programmed biological event.