Endogenous pyrogen release by fetal sheep and pregnant sheep blood leukocytes

Abstract

These experiments were undertaken to determine if fetal blood leukocytes are capable of producing endogenous pyrogen (EP), as neither the fetal nor newborn lamb can produce a fever in response to bacterial endotoxin. Maternal leukocytes were also tested for their ability to produce EP as the near-term pregnant sheep cannot produce a fever in response to bacterial endotoxins or EP. The results demonstrate that both fetal and near-term maternal leukocytes can produce EP, thus supporting experimental evidence that the inability of the newborn and near-term mother to become febrile is due to a process other than lack of EP production.