OS056. Angiotensin II sensitivity and endothelial dysfunction afterexperimental preeclampsia

Area of Science:

• Cardiovascular Research
• Reproductive Medicine
• Endocrinology

Background:

• Preeclampsia (PE) is linked to increased long-term cardiovascular and renal disease risk in women.
• Mechanisms may involve persistent endothelial dysfunction and heightened sensitivity to angiotensin II (Ang-II) post-pregnancy.
• Previous studies indicated vascular hypersensitivity to Ang-II in experimental PE rats.

Purpose of the Study:

• To investigate the persistence of vascular hypersensitivity to Ang-II and endothelial dysfunction postpartum in experimental PE.
• To compare Ang-II sensitivity and endothelial function in formerly preeclamptic rats versus healthy controls.

Main Methods:

• Comparison of non-pregnant (NP), formerly healthy pregnant (HP), and formerly preeclamptic (PE) rats six weeks postpartum.
• In vivo assessment of blood pressure response to Ang-II infusion over three weeks.
• In vitro analysis of aortic ring vasotonus, endothelium-dependent vasodilation (acetylcholine-mediated), and Ang-II receptor sensitivity (AT-1, AT-2).

Main Results:

• A trend towards increased systolic blood pressure response to Ang-II was observed in formerly PE rats compared to HP rats.
• No significant differences in in-vitro Ang-II sensitivity were found, but a trend suggested increased AT-2 receptor sensitivity in NP rats.
• While total acetylcholine-mediated endothelial relaxation was similar, the contributions of NO and EDHF appeared reduced in formerly pregnant rats.

Conclusions:

• Preliminary data suggest increased in-vivo Ang-II sensitivity postpartum in rats with a history of PE.
• Further research is needed to determine if these postpartum differences stem from in-vitro changes in Ang-II sensitivity or endothelial function alterations.