The enhanced endothelin-1-induced contraction in cultured coronary arteries from mature female pigs is not antagonized by 17β-estradiol

We have previously reported that organ cultured coronary arteries from market-age pigs (6-9 months of age) exhibit an enhanced contraction to the atherosclerotic-associated peptide, endothelin-1 (ET-1). The objective of this study was to investigate the interaction of 17β-estradiol with ET-1 in organ cultured coronary arteries from older female pigs (3-4 years old). A cumulative concentration-response relationship (1 × 10− 9 M to 3 × 10− 7 M) was generated to ET-1, and the isometric tension measured in fresh and organ cultured (4 days at 37 °C) arterial rings that were each pre-incubated for 50 min in different concentrations (1 × 10− 9 M to 1 × 10− 5 M) of 17β-estradiol. Compared to freshly used arteries, culturing induced a 2-fold increase in tension development to ET-1 (3 × 10− 7 M). Although 17β-estradiol previously relaxed pre-constricted (with a 60 mM KCl solution) arteries, it did not affect the constrictive response to ET-1. Also, using an ET-1 ELISA we found that 17β-estradiol did not effect ET-1 production in intact arteries. Our results indicate that 17β-estradiol does not attenuate the production and constrictive properties of ET-1 in coronary arteries demonstrating a dedifferentiated cell phenotype.