Age Dependent Changes of Certain Peptide Hydrolases and Dehydrogenases in Bovine Dental Pulp

The concentrations of certain peptide hy-drolases and enzymes of the aerobic and anaerobic catabolic cycles in the fibroblasts of bovine dental pulp have been examined as a function of the developmental stage of the tissue. It was shown that the enzyme content does not change uniformly during the aging process. Anaerobic catabolic path-ways remained unchanged or increased with cell maturity whereas the citric acid cycle activity decreased. Peptide hydrolases re-mained essentially constant. Fisher et all have observed a decrease in oxygen uptake in bovine dental pulp fibro-blasts with increasing maturity. Delbrueck2 examined the metabolic pattern in bovine cartilage and found that enzyme levels change as the cartilage matures. Human fetal cells derived from amniotic fluid were cultured by Nadler3 who subsequently dem-onstrated qualitative changes in glucose-6-phosphate dehydrogenase and lactate dehy-drogenase (LDH) activity in cells derived from different stages of fetal development. The system used by Fisher et all has the advantage of eliminating all sample ambi-guities. The fibroblasts in the various stages of development used for comparison were derived from the same species and the same organ (teeth). We have used this unique system to determine whether aging is accompanied by a general decline of all the enzymes in a cell or whether it is a pro-grammed process involving a shift in meta-bolic emphasis