Abstract
Micromolar concentrations of the biologically active oestrogen 17beta-oestradiol reduce agonist-induced force in vascular preparations through an unidentified mechanism. The aim of the present study was to investigate the importance of oestrogen receptor beta (ERbeta) for oestrogen-induced vascular relaxation. 17beta-oestradiol was added to aortic rings from ERbeta knock-out (-/-) and wild-type (+/+) mice precontracted with noradrenaline. 17beta-oestradiol caused a concentration-dependent (1-100 microM) relaxation of aortic rings from both -/- and +/+ animals of both sexes. Rings from male and female -/- mice were more sensitive to 17beta-oestradiol than those from +/+ mice. Medial thickness, determined by computerized image analysis, was similar in rings from -/- and +/+ animals. Endothelium, as determined by immuno-cytochemistry, was present in -/- and +/+ aorta. Maximal noradrenaline evoked force and sensitivity to noradrenaline were similar in both groups. In summary ERbeta modulates vascular relaxation to microM concentrations of oestrogen; lack of ERbeta renders the vascular wall supersensitive to 17beta-oestradiol. Lack of ERbeta caused no change in vascular wall morphology suggesting that this ER subtype is not involved in vascular structure development.
Original language | English |
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Pages (from-to) | R5-9 |
Journal | Journal of Endocrinology |
Volume | 166 |
Issue number | 2 |
Publication status | Published - 2000 Aug |
Subject classification (UKÄ)
- Physiology
Free keywords
- Animals
- Aorta
- Body Weight
- Dose-Response Relationship, Drug
- Endothelium, Vascular
- Estradiol
- Estrogen Receptor beta
- Female
- Image Processing, Computer-Assisted
- Immunohistochemistry
- In Vitro Techniques
- Male
- Mice
- Mice, Knockout
- Microscopy, Fluorescence
- Muscle, Smooth, Vascular
- Norepinephrine
- Receptors, Estrogen
- Vasoconstriction