β-estradiol supplement reverses the changes in the percentages of various T lymphocyte subpopulations in peripheral circulation of SHR. The percentage of CD3+, CD3+CD4+, CD3+CD8+, CD4+ CD25+ T cells was analyzed by flow cytometry. (A) Flow cytometry dot plots represent the percentages of circulating T lymphocytes subtypes in the peripheral blood of SHR and WKY rats. Decrease in the CD3+ T cell population and CD4+/CD8+ T cell subset ratios, and increased percentage of CD4+CD25+ T cells were observed following β-estradiol treatment in SHR. (B) Bar graphs represent the percentage of various T cell subpopulations and CD4+/CD8+ T cell subset ratios. All numerical data are displayed as the mean ± standard error (n=6/group). **P<0.01 vs. WKY group and SHR group without any drug treatment. #P<0.05 SHR group without any drug treatment vs. SHR group given β-estradiol. SHR, spontaneously hypertensive rat; WKY, Wistar-Kyoto rats; CD, cluster of differentiation; SHR + E, SHR + β-estradiol; FITC, fluorescein isothiocyanate; PE, phycoerythrin; APC, allophycocyanin; FSC, forward scatter.