Abstract: TH-PO193
Sex Differences in Renal Blood Flow Autoregulation Do Not Explain the Sex Disparity in CKD Progression
Session Information
- Hypertension and CVD: Basic Research Findings
October 24, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Hypertension and CVD
- 1601 Hypertension and CVD: Basic
Authors
- Polichnowski, Aaron J., East Tennessee State University James H Quillen College of Medicine, Johnson City, Tennessee, United States
- Chivers, Jacqueline M., East Tennessee State University James H Quillen College of Medicine, Johnson City, Tennessee, United States
- Chopde, Purva R., Illinois Institute of Technology, Chicago, Illinois, United States
- Williamson, Geoffrey A., Illinois Institute of Technology, Chicago, Illinois, United States
- Griffin, Karen A., Loyola University Chicago Stritch School of Medicine, Chicago, Illinois, United States
Background
We recently demonstrated an increased susceptibility to hypertensive renal injury in male vs. female rats. Sex differences in renal blood flow (RBF) autoregulation (AR) may contribute, in part, to the sex disparity in susceptibility to hypertensive renal injury and progression of chronic kidney disease (CKD); however, there are limited data available. Here, we investigated whether sex differences exist in RBF AR in uninephrectomized (UNX) rats before and during the administration of deoxycorticosterone acetate (DOCA) + salt.
Methods
Male (n=7) and female (n=8) Sprague-Dawley (SD) rats (10-13-week-old) underwent UNX. Two weeks later, rats were instrumented with a blood pressure (BP) radiotelemeter and a RBF probe. One week later, BP and RBF were assessed in the conscious state for 2-3 hours/day over 3 consecutive days prior to (i.e., baseline) and during days 3-7 of DOCA (3.3 mg/day) + salt (1% NaCl via drinking water) administration. We assessed dynamics of RBF AR using the short-segment AR index (SSARI, PMID 31792155) applied to adjacent time segments with >2.5 mmHg BP differences, as well as transfer function analysis. A 2-way repeated measures ANOVA with Sidak post hoc test was used for analysis. Data are mean±SE and P<0.05 was considered statistically significant.
Results
As shown in Table 1, RBF was higher (P<0.05) and renal vascular resistance (RVR) lower (P<0.05) in males at baseline and during DOCA + salt administration; however, no sex differences were observed in mean arterial pressure (MAP). DOCA + salt increased RBF and decreased RVR in both sexes (P<0.05), but only increased MAP (P<0.05) in males. No significant sex differences were observed in any measure of RBF AR. DOCA + salt decreased SSARI (i.e., strengthened RBF AR) for 2.5 second segments in females (P<0.05) but not males (P=0.10), and increased (P<0.05) the operating frequency of the myogenic mechanism in both sexes. In contrast, DOCA + salt decreased (P<0.05) the fractional gain at the myogenic frequency in both sexes.
Conclusion
Sex differences in RBF AR do not appear to be playing a significant role in the sex disparity in susceptibility to hypertensive renal injury and CKD progression.
Funding
- Other NIH Support