Evaluation of the effects of isoflurane on the bioavailability of nitric oxide in gestational hypertension in rats

Author(s)

Serginara David Rodrigues

• Document type: Master's Dissertation
• Press: Botucatu. 2023-08-24.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2023-07-31
• Advisor: Carlos Alan Candido Dias Junior

Abstract

Pregnancy hypertension-induced endothelial dysfunction associated with hemodynamic derangements is a challenge for urgent procedures that require maternal anesthesia. The volatile anesthetic isoflurane has demonstrated nitric oxide (NO)-associated protective effects. Impairment of NO bioavailability has also been related to hypertensive disorders of pregnancy. However, this isoflurane-induced effect is still unclear in pregnancy hypertension. Therefore, the present study examined the potential protective effects of isoflurane anesthesia on endothelial dysfunction and hemodynamic changes induced by hypertensive pregnancy associated with fetal and placental growth restriction. Animals were distributed into four groups: normotensive pregnant rats (Preg), anesthetized pregnant rats (Preg+Iso), hypertensive pregnant rats (HTN-Preg) and anesthetized hypertensive pregnant rats (HTN-Preg+Iso). Systolic, diastolic and mean arterial pressures, heart rate, fetal and placental weights, vascular contraction, endothelium-derived NO-dependent vasodilation, and NO levels were assessed. The vascular endothelial growth factor (VEGF) levels and endothelial NO synthase (eNOS) Serine (1177) phosphorylation (p-eNOS) expression were also examined. Our results demonstrate that isoflurane anesthesia produced more expressive hypotensive effects, which were related to the preventions against fetal and placental weight losses, hyper-reactive vasocontraction response, impaired endothelium-derived NO-dependent vasodilation, reduced VEGF levels, and decreased p-eNOS expression in the HTN-Preg+Iso rats compared to HTNPreg group. In conclusion, isoflurane anesthesia protects maternal endothelial function in pregnancy hypertension, and possibly endothelium-derived NO is involved. (AU)

• FAPESP's process: 21/03792-1 - Evaluation of isoflurane effects on nitric oxide bioavailability during the gestational hypertension in rats
• Grantee: Serginara David Rodrigues
• Support Opportunities: Scholarships in Brazil - Master