Increased activities of acid protease and acid phosphatase in denervated forelimb regenerates of the adult newt, Notophthalmus viridescens.

Early bud and palette limb regenerates of the adult newt, Notophthalmus viridescens, were compared with respect to the effect of denervation on the activities of some of their hydrolases in order to determine if these enzymes contribute to the atrophy of denervated regenerates. Results show that denervation increased total activities of acid protease and acid phosphatase by 77-89% and 41-45% respectively at both stages examined. Both membrane-bound and soluble enzymatic forms contributed to the observed increase in the total activity of each hydrolase. Furthermore, the actual levels of each enzyme attained at the two stages following denervation were quite similar to each other. Since each hydrolase responded to denervation in a similar way at both stages examined, it was concluded that resorption of denervated limb regenerates is not primarily due to the increased activity of hydrolases. Denervated early bud regenerates, which are almost completely resorbed following nerve withdrawal, would be expected to show greater levels of hydrolytic activity than denervated palette regenerates, which exhibit only a partial resorption following the same operation.