Acute exogenous oestradiol augments endothelial and smooth muscle vasodilatory responsiveness in premenopausal but not postmenopausal females

Figures

• 

  Figure 1. Endothelium‐dependent vasodilatation The vasodilatory responses to ACh alone (control, circles) and concurrent oestradiol infusion (oestrogen, squares) in young, premenopausal (A and B) (n = 9) and postmenopausal (C and D) (n = 9) females. The absolute forearm vascular conductance (FVC) dose responses are in (A) and (C) and the total FVC vasodilatory responses (area under the curve, AUC) are in (B) and (D). The grey symbols in (B) indicate the females taking oral contraceptives. B, baseline. A and C, two‐way repeated measures ANOVA. B and D, paired t tests and Cohen's d. *P < 0.05: dose vs. baseline.

• 

  Figure 2. Endothelium independent vasodilatation The vasodilatory response to sodium nitroprusside alone (control, circles) and concurrent oestradiol infusion (oestrogen, squares) in young, premenopausal (A and B) (n = 9) and postmenopausal (C and D) (n = 8) females. The absolute forearm vascular conductance (FVC) dose responses are in (A) and (C) and the total FVC vasodilatory responses (area under the curve, AUC) are in (B) and (D). The grey symbols in (B) indicate the females taking oral contraceptives. B, baseline. A and C, two ‐way repeated measures ANOVA. B and D, paired t tests and Cohen's d. *P < 0.05: dose vs. baseline; ǂP < 0.05 control vs. oestrogen.

• 

  Figure 3. β2‐adrenergic receptor‐mediated vasodilatation The vasodilatory response to terbutaline alone (control, circles) and concurrent oestradiol infusion (oestrogen, squares) in young, premenopausal (A and B) (n = 9) and postmenopausal (C and D) (n = 9) females. The absolute forearm vascular conductance (FVC) dose responses are in (A) and (C), and the total vasodilatory responses (area under the curve, AUC) are in (B) and (D). The grey symbols in (B) indicate the females taking oral contraceptives. B, baseline. A and C, two‐way repeated measures ANOVA. B and D, paired t tests and Cohen's d. *P < 0.05: dose vs. baseline; #P < 0.05 dose vs. baseline in oestrogen only; ǂP < 0.05 control vs. oestrogen.

• 

  Figure 4. Association between time post‐menopause and the vasodilatory responses with oestradiol Linear relations between years subsequent to menopause and the change in the total vasodilatory response with acute oestradiol infusion (∆total vasodilatation = oestradiol AUC – control AUC) during endothelium‐dependent (A), endothelium independent (B), or β2‐adrenergic receptor mediated (C) vasodilatation assessed via Pearson correlation coefficient (r). AUC, area under the curve.