CONTENTS OF ADENINE-NUCLEOTIDES AND GLYCOLYTIC AND TRICARBOXYLIC-ACID CYCLE INTERMEDIATES IN ACTIVATED AND NON-ACTIVATED PLEROCERCOIDS OF SCHISTOCEPHALUS-SOLIDUS (CESTODA, PSEUDOPHYLLIDEA)

The steady state content of adenine nucleotides Pi and glycolytic and tricarboxylic acid cycle intermediates were measured in freeze clamped plerocercoids of S. solidus taken from the body cavity of infected Gasterosteus aculeatus fish (non-activated plerocercoids) and the results compared with the metabolic levels in plerocercoids which had been cultured in vitro for 12 h (activated pleurocercoids). Of the glycolytic intermediates, the levels of fructose-6-phosphate, fructose-1,6-diphosphate, 3-phosphoglycerate, phosphoenolpyruvate and lactate all decreased on activation, while the remainder of the glycolytic intermediates did not alter significantly. The levels of the tricarboxylic acid cycle intermediates all increased 2- to 3-fold on activation, while the adenine nucleotides remained virtually unchanged. The differences in the steady state content in intermediary metabolites in activated and non-activated plerocercoids are discussed in relation to possible mechanisms of metabolic control.