Time course changes in blood metabolites during endotoxin fever in sheep.

Time course changes in the concentration of plasma amino acids, glucose, insulin, and creatinine were measured in seven mature sheep during fever induced by Escherichia coli (serotype 055:B5) endotoxin. Rectal temperature was increased above that recorded in control animals from 0.75 to 6.25 h postinjection with a maximum rise of 2.3 degrees C. Total amino acid concentrations decreased (P less than 0.05) 4.5 h postinjection and remained depressed (P less than 0.05) until 19 h postinjection. The plasma concentration of each individual amino acid decreased (P less than 0.05) at some point during the experiment with the exception of tryptophan and tyrosine. Glucose concentration decreased (P less than 0.05) and remained depressed until at least 55 h postinjection. Plasma insulin concentration was elevated (P less than 0.05) from 4.5 to 13 h postinjection. Plasma creatinine concentration increased during fever (P less than 0.05) and returned to normal by 31 h postinjection.