Correlation between estrogen receptor α expression, collagen content and stiffness in human uterine arteries

AIM OF THE STUDY: To investigate the relationship between estrogen receptor alpha expression, collagen content and distensibility of the human uterine artery. STUDY DESIGN: Uterine arteries (n = 13) obtained from women undergoing hysterectomy were mounted for length-tension relations and thereafter frozen for later determination of collagen and estrogen receptor alpha contents. RESULTS: A negative correlation between estrogen receptor alpha content and collagen content (r = -0.76, n = 13) and a positive correlation between collagen content and passive tension at 1.4 Lo (r = 0.72, n = 13) in the uterine artery were detected. No difference was found between pre- and postmenopausal women concerning the estrogen receptor alpha content, the collagen content or maximal active force. CONCLUSIONS: Our data show a functional correlate to the expression of estrogen receptors alpha, as a high content of estrogen receptor alpha correlates with a lower collagen concentration, indicating that estrogen through activation of estrogen receptor alpha protects against vascular collagen accumulation making the vessel more distensible.