Cytotoxic CD8+ Interleukin (IL)‐17+ T‐cells Play a Role in Hypertension‐Specific Inflammatory Responses Associated with Ovariectomy in Dahl Rats

Abstract

Background and ObjectiveOophorectomy is associated with increased body weight (BW) gain and incidence of hypertension (HT) compared with age‐matched women. Increased BW gain and HT coincide with increased inflammatory biomarkers. To separate immune responses due to HT from those due to BW gain, we compared T‐cell subpopulations in normotensive Dahl (DR) and hypertensive Dahl (DS) rats after ovariectomy.MethodsSix week old DS and DR rats were ovariectomized (Ovx) or had sham surgery (Sham). Mean arterial pressure (MAP) was measured in anesthetized rats after 4 and 10 months (mo) acutely by indwelling vascular catheter. Splenic T‐cells were assessed by flow cytometry at 10 mo.ResultsOvariectomy increased the MAP in DS but not DR rats at 4 mo [MAP (mmHg): DS‐Ovx, 143±1.0 vs DS‐Sham, 129±2.9; p=0.0002 & DR‐Ovx, 123±4.4 vs DR‐Sham, 126±1.3; ns n=10–12/group]. At 10 mo, the MAP remained higher in the ovariectomized DS compared to DR rats [MAP (mmHg): DS‐Ovx, 190±12 vs DR‐Ovx, 114±1.2; n=5–8/group; p=0.002]. At 10 mo, ovariectomy increased BW to a similar extent in DS and DR rats [BW gain (g): DS, 179±13 vs DR, 202±14; ns]. The frequency of CD8+IL17a+ T‐cells increased in the ovariectomized DS but not DR rats [Frequency (%) at 10 mo: DS‐Ovx, 9.6±2 vs DR‐Ovx, 1.3±0.4; n=5–8/group; p<0.0001].ConclusionCytotoxic CD8+ IL‐17a+ T‐cells may play a role in the HT‐specific inflammatory response in ovariectomized DS rats.Support or Funding InformationGeorgetown University Medical Center, and Translational Biomedical Science Predoctoral Training Program Georgetown‐Howard Universities Center for Clinical and Translational Science