INTERMEDIARY METABOLISM OF CATTLE LUNGWORM DICTYOCAULUS VIVIPARUS

Metabolic pathways of the adult cattle lungworm, Dictyocaulus viviparus, from the lungs of artificially infected calves, have been studied. From the results a diagram is postulated, in which glucose is metabolized according to the Embden MEYERHOF-route. In addition to this the citric acid cycle is operative. An important pathway, not found in the mammalian cell, is a carbon dioxide fixation mechanism in which, after carbon dioxide fixation to phosphoenolpyruvate, oxaloacetate is formed, catalyzed by a phosphopyruvate carboxylase. The dicarboxylic acid is converted into succinate by reversal of some reactions of the citric acid cycle. The succinoxidase system shows a higher rate of fumarate reduction than of succinate oxidation. Cytochromes are not present in demonstrable amounts, the terminal oxidase of the respiratory chain is believed to be a flavoproteiNsystem. © 1969, IEEE. All rights reserved.