Influence of estrogen and/or progesterone on isolated ovariectomized rat uterus. Responsiveness to Ang II.

Steroids hormones can influence several functions of the uterus, including agonist-induced contractions. The aim of this work is to study the influence of hormonal replacement on angiotensin II (Ang II) and losartan responsiveness on the isolated rat uterus. The Ang II pD(2) values are: 9.69 +/- 0.07 for vehicle-treated animals, 8.85 +/- 0.06 for estrogen-treated animals, 10.12 +/- 0.03 for progesterone-treated animals and 8.90 +/- 0.03 for estrogen-and-progesterone-treated animals. The losartan pD(2)' values are: 8.43 +/- 0.03 for vehicle-treated animals, 8.21 +/- 0.03 for estrogen-treated animals, 7.83 +/- 0.05 for progesterone-treated animals and 8.70 +/- 0.09 for estrogen-and-progesterone-treated animals. There is not a correlation between Ang II pD(2) and losartan pD(2)' values, suggesting that the hormones affect Ang II and losartan binding by different mechanisms in rat uterus. Copyright 2002 S. Karger AG, Basel