Optical coherence tomography is a feasible imaging modality in patients with AMI and allows us to identify not only plaque rupture, but also fibrous cap erosion, intracoronary thrombus, and TCFA in vivo more frequently compared with conventional imaging techniques.
Abstract-Many studies have shown that estrogen may exert cardioprotective effects and reduce the risk of hypertension and coronary events. On the other hand, it has been proposed that cell membrane abnormalities play a role in the pathophysiology of hypertension, although it is not clear whether estrogen would influence membrane function in essential hypertension. The present study was performed to investigate the effects of 17-estradiol (E 2 ) on membrane fluidity of erythrocytes in normotensive and hypertensive postmenopausal women. We determined the membrane fluidity of erythrocytes by means of an electron paramagnetic resonance and spin-labeling method. In an in vitro study, E 2 significantly decreased the order parameter for 5-nitroxide stearate and the peak height ratio for 16-nitroxide stearate obtained from electron paramagnetic resonance spectra of erythrocyte membranes in normotensive postmenopausal women. The finding indicates that E 2 might increase the membrane fluidity of erythrocytes. The effect of E 2 was significantly potentiated by the NO donor, S-nitroso-N-acetylpenicillamine, and a cGMP analogue, 8-bromo-cGMP. In contrast, the change in the membrane fluidity evoked by E 2 was attenuated in the presence of the NO synthase inhibitor, N G -nitro-L-arginine methyl ester, and asymmetric dimethyl-L-arginine. In hypertensive postmenopausal women, the membrane fluidity of erythrocytes was significantly lower than that in normotensive postmenopausal women. The effect of E 2 on membrane fluidity was significantly more pronounced in the erythrocytes of hypertensive postmenopausal women than in the erythrocytes of normotensive postmenopausal women. The results of the present study showed that E 2 significantly increased the membrane fluidity and improved the microviscosity of erythrocyte membranes, partially mediated by an NO-and cGMP-dependent pathway. Furthermore, the greater action of E 2 in hypertension might be consistent with the hypothesis that E 2 could have a beneficial effect in regulating rheological behavior of erythrocytes and could have a crucial role in the improvement of the microcirculation in hypertension. here is a strong link between menopause and an increased incidence of cardiovascular diseases, and recent studies have demonstrated that estrogen replacement therapy reduced morbidity or mortality due to coronary heart diseases in postmenopausal women. [1][2][3][4] It has also been shown that estrogen supplementation induced a significant fall in blood pressure in postmenopausal women. 5 These findings propose the idea that estrogen may exert protective effects against arteriosclerosis and hypertension. However, fundamental mechanisms of cellular and molecular events by estrogen are still unclear.It has been proposed that cell membrane abnormalities are an etiological factor in hypertension, including functional abnormalities, such as transmembrane cation fluxes. 6 -8 An electron paramagnetic resonance (EPR) and spin-labeling method have been developed to elucidate the membrane fluid...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.