Estradiol endothelium

A double-blind, randomised, placebo-controlled study in postmenopausal women with hypercholesterolaemia and arterial hypertension found that whilst atorvastatin alone, estradiol alone, or the combination of both had beneficial effects on the lipid profile and endothelium-dependent vasodilatation, these effeets were abolished by the addition of norethisterone. It was suggested that progesterone derivatives with high androgenic activity, such as norethisterone, have a negative effect on lipid profile. ... 

Endothelial NOS (eNOS) is responsible for producing NO in the vascular wall (reviewed in ref. 58). In rat aortic EC, acute exposure to both estradiol and insulin-like growth factor (IGF)-l was associated with an increase in eNOS activity (59). The presence of abnormal ECM in the vessel wall could be responsible for decreased NO synthesis (60), however, chronic over expression of eNOS accelerates atherosclerosis under hypercholesterolemia. eNOS dysfunction, demonstrated by lower NO production relative to eNOS expression and enhanced superoxide production in the endothelium, appears to play important roles in the progression of atherosclerosis in Apo E KO/eNOS transgenic mice (61). 

Amant C, Holm P, Xu Sh SH, et al. Estrogen receptor-mediated, nitric oxide-dependent modulation of the immunologic barrier function of the endothelium regulation of fas ligand expression by estradiol. Circulation 2001 104 2576-2581. 

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