Glycolytic Activity of the Tooth Germ

¹ Department of Biochemistry, School of Dentistry, Tokyo Medical and Dental University, Tokyo, Japan

Lactic acid, glucose, and glycogen contents and glycolytic activity of bovine tooth germ separated into the enamel organ and the dental papilla were determined. The mean values of lactic acid contents were 0.79 mg./Gm. for the enamel organ and 0.98 mg./Gm. for the dental papilla. Mean values of glucose were 0.49 mg./Gm. for the enamel organ and 0.37 mg./Gm. for the dental papilla. Glycogen content decreased concomitantly with the weight increase of the tooth germ and was four to ten times higher in the enamel organ than in the dental papilla.

The mean QN2COCO2 value of glycolysis in the enamel organ was 2.6 and was increased to 3.4 by glucose addition. The dental papilla had low activity, which averaged 0.5, but increased to 2.9 when glucose was added. Activity of aerobic glycolysis was about half that in anaerobic glycolysis, but the effect of glucose on the dental papilla was significant.

After manometry, lactic acid was found to be higher than the value expected from the CO₂ measured by manometry, and this may have been present before the manometric incubation. Anaerobic glucose consumption by the enamel organ was lower than the value equivalent to CO₂, probably because of glycogen utilization. Aerobic glucose consumption exceeded the value equivalent to CO_2.