The effects of anoxia on metabolism in the adult housefly, musca domestica

Abstract

Houseflies were injected with [2-14C]acetate and were left in air for 1 hr. Some were then killed, some were left in air for a further 1 hr. or 2 hr., and others were put into oxygen-free nitrogen for 1 hr. or 2 hr. In the aerobic flies 14c-labelled [alpha]-alanine, aspartate, glutamate, glutamine, proline, gamma-amino-butyrate, fumarate, malate, [alpha]-oxoglutarate, pyruvate, succinate and glutathione were present. In the anoxic flies all the above intermediates were present as well as 14C- labelled lactate and three other unidentified 14C-labelled intermediates. In the anoxic flies there was an increase in the concentration of [alpha]-alanine, but there was a fall in the concentrations of aspartate and of glutamine. The concentration of pyruvate rose during the first 30 min. of anoxia but later returned to its original value. There was a rise in the 14C activity of lactate, of succinate and of gamma- aminobutyrate. In the aerobic flies the specific activity of the protein amino acids increased whereas in the anoxic flies their specific activity either decreased or remained the same.