 The increase in cortisol in diarrheic calves is minimal over healthy calves, however, and falls over time.The cells do not lose all their fight-or-flight override because of interleukin-1's synergism with CRH.Cortisol even has a negative feedback effect on interleukin-1—especially useful to treat diseases that force the hypothalamus to secrete too much CRH, such as those caused by endotoxic bacteria.