[Changes in the amount of free amino acids in infections due to Gram-negative agents]

Changes of free amino acid content in blood plasma from sheep and hens infected with S. abortus ovis and P. multocida or treated with purified lipopolysaccharides (endotoxins) of the respective agent, were studied. It was established that the infection reduced total free amino acid content by about 46% in sheep and by 36% in hens. The reduction in total free amino acid content did not affect to the same extent each individual amino acid. Treatment of sheep and hens only with purified lipopolysaccharides of respectively S. abortus ovis and P. multocida resulted also in reduced total free amino acid content equal to 33% in sheep and about 59% in hens. The reduced content of total free amino acids in this case also did not concern equally the individual amino acids. However, in all cases observed, when a given amino acid was reduced during the infection period the same reduction was evident following endotoxin treatment only. The conclusion is drawn that disturbances in cell metabolism arising under the influence of endotoxins let free by the respective agent are the main cause for the reduction both of total free amino acid content and of the individual free amino acid content.