METABOLIC FATE OF GLUCOSE AND PYRUVATE IN NERVE CORD OF HOMARUS VULGARIS (M EDW) AND ASTACUS FLUVIATILIS (F)

1. 1. The study of the production of C14O2 from pyruvate-1-C14, glucose-1-C14, glucose-6-C14 and glucose-U-C14 demonstrates that: (a) The operations of the Krebs cycle seem to be faster in the nerve cord of the crayfish, Astacus fluviatilis (F.) than in the lobster Homarus vulgaris (M. Edw.). (b) Besides the classic sequences of glycolysis and the Krebs cycle, the lobster and the crayfish possess the hexosemonophosphate and the glucuronate pathways. 2. 2. Veratrine sulphate (4 μM), cocaine chloride (4 mM) and NH4Cl (10 mM) inhibit the Krebs cycle in the nerve cord of both lobster and crayfish. 3. 3. These three substances seem to stimulate the hexosemonophosphate pathway. 4. 4. Veratrine and NH4Cl stimulate the glucuronate pathway while cocaine inhibits it. © 1969.