Abstract: PO0148
Glomerular Filtration Fails to Increase During Pregnancy After Recovery from Ischemia-Reperfusion Injury
Session Information
- AKI Mechanisms - 1
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Authors
- Gillis, Ellen Elizabeth, Augusta University, Augusta, Georgia, United States
- Brands, Michael W., Augusta University, Augusta, Georgia, United States
- Sullivan, Jennifer C., Augusta University, Augusta, Georgia, United States
Background
Renal demands are increased during normal pregnancy due to the large increase in plasma volume and cardiac output, with a corresponding increase glomerular filtration rate and decreased blood pressure (BP). Recent studies in our laboratory have reported that pregnancy after recovery from ischemia reperfusion (IR) injury results in poor maternal and fetal outcomes, including decreased fetal weight, increased fetal demise, and mild uremia in the dams. In the current study, we hypothesized that glomerular filtration fails to increase during pregnancy in these dams after recovery from IR.
Methods
Female Sprague Dawley rats (10 weeks of age, n=3) were implanted with telemeters into the femoral artery for continuous BP measurements. Following 10 days of recovery, rats were randomized to receive either 45 minutes of warm, bilateral renal ischemia or sham surgery. Rats were then given 1 month to recover. Full recovery from IR was confirmed by return of plasma creatinine and urinary protein excretion to baseline prior to mating. Vaginal smears were performed daily once mating began, to identify gestational day 1. Glomerular filtration rate was calculated using creatinine clearance (using 24 hour urine collection from gestational days 19-20 and plasma creatinine on gestational day 20).
Results
BP decreased to a similar extent (7±1.2mmHg in control vs 8±1.2mmHg in IR dams) by gestational day 20, however the decrease in BP was delayed in the IR dams, resulting in an overall higher pressure load as determined by area under the curve analysis (2080±33 vs 2184±16, p<0.05, t-test). Glomerular filtration rate was significantly higher in control dams compared to IR dams (3.1±0.7mL/min vs 1.6±0.1mL/min, p<0.05).
Conclusion
These data suggest that after recovery from IR, the kidneys are unable to appropriately increase glomerular filtration rate during pregnancy. Ongoing studies in the laboratory are focused on alterations in plasma volume expansion during pregnancy after IR. We propose that plasma volume expansion, characteristic of normal pregnancy, is absent in this model, leading to decreased placental perfusion and poor fetal growth.
Funding
- Other NIH Support