P3: The Extent of Endothelial Dysfunction in the Femoral Artery is Similar in the Juvenile Male and Female Spontaneously Hypertensive Rats

Abstract

Objectives

Endothelial dysfunction (ED) plays an important role in the pathogenesis of hypertension. In this work, we studied sex differences in the endothelium-dependent relaxation (EDR) of the femoral artery (FA) and its nitric oxide (NO)-dependent and NO-independent components in peri-pubertal (7-week-old) spontaneously hypertensive male and female rats (SHR). Age-matched Wistar-Kyoto (WKY) rats served as the control groups.

Method

Systolic blood pressure (sBP) was measured non-invasively by tail-cuff. Vascular studies were conducted using the wire myograph at isometric conditions. EDR was determined using acetylcholine test. Biochemical parameters (lipid profile, uric acid) were determined in plasma.

Results

We found a significant increase in sBP of SHR vs. WKY, however, there were no sex-dependent differences in sBP. Significantly reduced EDR was found in both male and female SHR and the extent of ED was similar in males and females. ED in SHR of both sexes was associated with a reduced NO-independent component, while NO- dependent component was reduced only in females. Concentrations of high-density lipoproteins were significantly increased in females vs. males in both WKY and SHR. Uric acid concentration was decreased only in male SHR vs. male WKY.

Conclusion

In conclusion, we did not find differences in sBP and overall endothelial function between juvenile SHR males and females. ED in both young SHR males and females was NO-independent. In addition, results suggested the association between low serum uric acid concentrations and ED in male SHRs. Supported by the grants VEGA No. 2/0190/17, APVV-16-0263 and Slovak Society of Cardiology.