Tumor Necrosis Factor-alpha impairs cerebral blood flow in pregnant rats: Role of vascular beta-Epithelial Na+ Channel.

Tumor Necrosis Factor-alpha impairs cerebral blood flow in pregnant rats: Role of vascular beta-Epithelial Na+ Channel. Am J Physiol Heart Circ Physiol. 2020 Mar 13;: Authors: Duncan J, Younes ST, Hildebrandt E, Ryan MJ, Granger JP, Drummond HA Abstract Preeclampsia is a pregnancy-related disorder characterized by hypertension, vascular dysfunction and an increase in circulating inflammatory factors including the cytokine, tumor necrosis factor-alpha (TNF-α). Studies have shown that placental ischemia is associated with 1) increased circulating TNF-α, 2) attenuated pressure-induced cerebral vascular tone and 3) suppression of beta-Epithelial Na+ Channel (βENaC) protein in cerebral vessels. βENaC is an essential signaling element in transduction of pressure-induced (aka "myogenic") constriction, a critical mechanism of blood flow autoregulation. While cytokines inhibit expression of certain ENaC proteins in epithelial tissue, it is unknown if the increased circulating TNF-α associated with placental ischemia mediates the loss of cerebrovascular βENaC and cerebral blood flow regulation. Therefore, the purpose of this study was to test the hypothesis that increasing plasma TNF-α in normal pregnant rats reduces cerebrovascular βENaC expression and impairs cerebral blood flow (CBF) regulation. In vivo TNF-α infusion inhibited cerebrovascular expression of βENaC and impaired CBF regulation in pregnant rats. To determine the direc...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research