Goal of the Study:
Up to 20% of women receiving epidural analgesia experience epidural-related maternal fever (ERMF) [1,2]. Importantly, intrapartum maternal fever is associated with increased perinatal mortality and neonatal morbidity [3]. This cell culture study investigates the dose-dependant effect of ropivacaine and possible alleviating impact of dexamethason on human umbilical vein endothelial cells (HUVECs) and human placental trophoblasts (TBs).
Methods:
HUVECs and TBs were exposed to ropivacaine (0.001 – 0.2% or 35uM-7mM) with our without dexamethason (1uM) for 1,4 and 24 hours. FACS analysis and LDH release was used to detect apoptosis and cytotoxicity. Pro-inflammatory interleukins-6 (IL-6) and -8 (IL-8) and pyrogenic mediator PGE 2 were measured by ELISA. The activation of signaling pathways was detected by Western blotting. Cellular oxidative stress was visualized by live cell imaging and quantification of antioxidant proteins by real-time PCR. Mitochondiral injury was assessed with JC-1 staining as well as real-time PCR for mitochondiral DNA release.
Results and Discussion:
Compared to controls, our results show that ropivacaine causes apoptosis and cell cytotoxicity in HUVECs (p < 0.01). In the intervention groups higher IL-6 and PGE 2 concentrations were found in HUVECs (p < 0.01), while in HPs IL-6 and IL-8 was significantly increased (p < 0.01). Caspase-3, NfkB and p38 MAP-kinase pathways were activated by ropivacaine. We found a transient dephosphorylation of ERK and a more persistent dephosphorylation of Akt – indicating a deactivation of these “survival kinases”. The above mentioned effects could be reversed by addition of dexamethason (i.e., significant reduction of apoptosis, LDH, IL-6 and PGE 2; all p < 0.01). The downregulation of superoxide dismutases and visualisation of cellular oxidative stress suggests that ropivacaine induces an imbalance in the redox homeostasis.
Conclusion:
This cell culture study suggests that ropivacaine causes inflammation, cellular injury and death in HUVECs and TBs possibly via oxidative stress and the down stream pathway of NfkB. The observed involvement of ROS in this context prospects for potential futur theraputic cocepts for ERMF.
References:
[1] Lieberman E. Epidural analgesia, intrapartum fever, and neonatal sepsis evaluation. Pediatrics 1997;99:415 – 9
[2] Bensal A. The significance of peripartum fever in women undergoing vaginal deliveries. American Journal of perinatology 2008;25;567 – 72
[3] Greenwell EA. Intrapartum temperature evelation, epidural use, and adverse outcome in term infants. Pediatrics 2012;129:e447 – 54
