CHANGES IN ENERGETIC SUBSTRATES DURING THE REGENERATION OF PLANARIANSDUGESIA-TIGRINA (GIRARD)

1. Biochemical modification of the energy substrates of a planarian sp ecies [Dugesia tigrina (Girard)] were studied as a function of regener ation. 2. The activities of creatine kinase (CPK), assays of ATP, glyc ogen and the incorporation of [U-C-14]-glucose in glycogen were measur ed in regenerating planarians at regular intervals of time from the be ginning of the regenerative process to the complete restoration of the animal. 3. The enzymatic activities and metabolites were substantiall y altered during the regeneration period of cephalic as well as caudal segments. 4. The analysis of ultrastructural sites of glycogen by ult racytochemical assays showed differences during the regeneration of ce phalic and caudal segments.