Evidence for mechanisms of the acute-phase response to endotoxin in late-gestation fetal goats.

Abstract

The aim of this study was to evaluate the relationship between febrile response to fetal endotoxin administration and fetal plasma endogenous pyrogen, tumor necrosis factor-alpha, the possible putative pyrogen mediator prostaglandin E2, and the endogenous antipyretic arginine vasopressin in late-gestation pregnant goats. Changes in fetal core temperature, plasma tumor necrosis factor-alpha, prostaglandin E2, and arginine vasopressin levels were measured after administration of Escherichia coli endotoxin (70 microg/kg of fetal weight) to 10 fetal goats in late gestation. Fetal body temperature did not rise after endotoxin administration. Fetal plasma tumor necrosis factor-alpha and arginine vasopressin increased to 87.5 +/- 15.2 pg/mL and 25.1 +/- 4.8 pg/mL, respectively, after 1 to 2 hours (P < .05). Fetal plasma prostaglandin E2 levels did not change significantly throughout the study. The absence of a febrile response to endotoxin in late-gestation fetal goats is accompanied by a deficient responses in prostaglandin generation in the periphery and increased activity of the antipyrogen arginine vasopressin.