# Renal hemodynamics and hypertension during pregnancy

> **NIH NIH R01** · UNIVERSITY OF SOUTH FLORIDA · 2020 · $387,823

## Abstract

Normal pregnancy involves extensive and systemic physiological adaptations characterized by substantial
volume expansion and vasodilatation. The exact mechanisms for the physiological changes have not been fully
clarified, but relaxin (a corpus luteum-released hormone) has been found to play a central role in the control of
hemodynamics in normal pregnancy. Inappropriate or inadequate adaptations during pregnancy may induce
pathological consequences such as preeclampsia, which is characterized by new-onset hypertension and
proteinuria after 20 weeks of gestation. Renal hemodynamic alterations during preeclampsia are characterized
by reduced GFR and RBF by about 20-40% compared with normal pregnancies. Non-selective nitric oxide
synthesis (NOS) inhibition not only blocks the elevations in GFR and RBF during normal pregnancy, but also
induces hypertension and proteinuria, suggesting the essential role of nitric oxide (NO) in control of the
hemodynamics in normal pregnancy and preeclampsia.
 GFR is normally regulated by tubuloglomerular feedback (TGF) response. The significance of TGF response
in normal pregnancy and preeclampsia has not been elucidated. Specifically, whether the changes in TGF
response during normal pregnancy are a consequence of systemic vessel dilatation or the cause for the
increased GFR is unknown; whether the decreased GFR during preeclampsia is mediated by TGF
responsiveness, which induces or is a consequence of the development of hypertension is unknown; and
whether NOS1β in the macula densa mediates TGF alterations and triggers the development of hypertension
during preeclampsia is unknown. All of these unidentified areas will be explored in the present proposal.
 We will test our hypothesis that NOS1β in the macula densa increases during normal pregnancy, which
blunts TGF responsiveness that contributes to maintaining increased GFR and decreased blood
pressure. During preeclampsia, factors that are released from the placenta decrease the macula densa
NOS1β expression and activity, which enhances TGF responsiveness. Elevations of GFR in pregnancy
are limited by the enhanced TGF response, which reduces sodium excretion, impairs pressure
natriuresis, and thereby induces hypertension.

## Key facts

- **NIH application ID:** 9856365
- **Project number:** 5R01HL137987-03
- **Recipient organization:** UNIVERSITY OF SOUTH FLORIDA
- **Principal Investigator:** RUISHENG LIU
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $387,823
- **Award type:** 5
- **Project period:** 2018-02-01 → 2022-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9856365

## Citation

> US National Institutes of Health, RePORTER application 9856365, Renal hemodynamics and hypertension during pregnancy (5R01HL137987-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9856365. Licensed CC0.

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