Oestrogenic vascular effects are diminished by ageing

The beneficial role of oestrogen in the vascular system may be due, in part, through reduction of peripheral vascular resistance. The use of oestrogen therapy to prevent cardiovascular disease in post-menopausal women remains contentious. This study investigated the influence of the menopause and ageing on the acute vasodilatory effects of oestrogen in ex vivo uterine resistance arteries.\n\nVessels were obtained from young (2.9 {+/-} 0.1 months) and aged (24.2 {+/-} 0.1 and 28.9 {+/-} 0.3 months) female mice and pre-(42.3 {+/-} 0.5 years) and post-menopausal (61.9 {+/-} 0.9 years) women. Ageing was associated with profound structural alterations of murine uterine arteries, including the occurrence of outward hypertrophic remodelling and increased stiffness. Endothelial and smooth muscle function were diminished in uterine (and tail) arteries from aged mice and post-menopausal women. The acute vasodilatory effects of 17{beta}-oestradiol (non-specific oestrogen receptor (ER) agonist), PPT (ER-specific agonist) and DPN (ER{beta}-specific agonist) on resistance arteries were attenuated by ageing and the menopause. However, the impairment of oestrogenic relaxation was evident after the occurrence of age-related endothelial dysfunction and diminished distensibility. The data indicate, therefore, that adverse resistance arterial ageing is a dominant factor leading to weakened vasodilatory action of oestrogenic compounds.