Abstract 155: Female Sex Hormones Blunt Renal Pro-inflammatory T Cell Infiltration Compared to Males
Lymphocytes contribute to hypertension in male spontaneously hypertensive rats (SHR); data in females is lacking, yet young females have a lower blood pressure compared to age-matched males. We hypothesized that 12 week old female SHR have less T cell infiltration and cytokine expression in the kidney compared to males. Kidneys were isolated from male and female SHR and normotensive Wistar Kyoto rats (WKY) and the T cell profile was determined using analytical flow cytometry. In both sexes of SHR, all T cell subtypes and cytokines measured were significantly higher in the kidney compared to the same sex WKY (p<0.05, n=6-8). Male SHR had greater CD4+ T cell infiltration vs. female SHR (p<0.0001), whereas the CD8+ T cell numbers were higher in female SHR (p=0.0114). Analysis of T cell subpopulations showed female SHR has greater expression of regulatory T cells (Foxp3+CD4+CD3+) than male SHR (p=0.0008), however, male SHR had more infiltrating pro-inflammatory Th17 cells (RORγ+CD4+CD3+; p<0.0001). Male SHR also had greater expression of pro-inflammatory cytokines, IL-17 and IL-6, on cells in the kidney than females, but female SHR expressed more IL-10, an anti-inflammatory cytokine (p<0.0001, all). Gonadectomy of female SHR significantly increased total T cell (CD3+; p=0.0009, n=3-6), CD4+ T cell (p=0.0010) and Th17 cell (p=0.0025) infiltration into the kidneys. Infiltration of CD8+ and Foxp3+ cells remained comparable between groups. Together these data suggest that hypertension in both sexes are associated with an increase in renal inflammatory markers; however female SHR have a more anti-inflammatory profile vs. males which may contribute to their lower blood pressure.
- © 2012 by American Heart Association, Inc.