The effect of Escherichia coli endotoxins on the concentrations of corticosterone and growth hormone in the plasma of the domestic fowl.

The intravenous injection of chickens aged six to 11 weeks with Escherichia coli endotoxins (serogroups O111 and O78) produced a large increase in the plasma corticosterone concentration which was maximal (five to 10-fold) after 1 h and still evident after 8 h. It did not vary with the dose over the range 0.1 to 2 mg/kg and was smaller than that produced by adrenocorticotrophic hormone (ACTH) (20 iu/kg). A decrease in growth hormone concentration was detected between 1 and 2 h after endotoxin administration in six- to seven-week-old birds, this change being opposite to that which occurs in man.