N-Acetyl-Glucosaminidase Activity during Limb Regeneration in the Adult Newt

Abstract

N-Acetyl-glucosaminidase activity was measured during the first 25 days of limb regeneration. It was found that the enzyme is present in the normal limb. Following amputation a significant drop was obtained at day 3. A significant increase in enzyme activity was found at day 5 followed by a second drop by day 10. For days 12–15 a second peak of enzyme activity was detected, followed by a third drop; by day 25, normal levels of enzyme activity were detected. Histochemical localization of the enzyme in tissue samples showing enzyme activity as detected biochemically (days 5 and 17 of regeneration) gave negative results. However, enzyme activity was found in the incubation medium, indicating that the enzyme is released from the cells. The peaks of enzyme activity coincide with the stages of limb regeneration where a high degree of tissue demolition and cell lysis occurs. The latter are important events in the regeneration process, cell dedifferentiation, and blastema formation.