Systemic vascular hemodynamic changes due to 17-β-estradiol intranasal administration.

Purpose: According to the literature, estradiol has a direct vasodilator action by means of endothelium-derived relaxing factor synthesis. The present study aims to evaluate the acute hemodynamic effects of intranasal 17-β-estradiol on cerebral and lower limb arterial circulation in postmenopausal women.

Methods: Sixteen healthy women in natural menopause (mean age: 54 ± 3 years) were investigated for at least 6 months, each receiving 300 µg of intranasal 17-β-estradiol. We evaluated the heart rate, systolic/diastolic blood pressure, peak systolic velocity, end-diastolic velocity, and velocity-time integral (VTI) at the level of internal carotid and posterior tibial arteries, before and after 30, 60, and 180 minutes of drug administration.

Results: After intranasal 17-β-estradiol administration, the internal carotid artery VTI showed statistically significant (P < .05) variations at all the time intervals after administration of the drug (30, 60, and 180 minutes) when compared with "time zero" (T0, ie, the speed recorded at baseline before drug administration). No significant variation was found at the posterior tibial artery. The systolic/diastolic blood pressure and heart rate did not significantly differ before and after drug administration.

Conclusions: The administration of a single intranasal dose of 17-β-estradiol in healthy postmenopausal women increased cerebral perfusions, whereas the effect on peripheral circulation was much more limited.