Gender differences in intima-media permeability to low-density lipoprotein at atherosclerosis-prone aortic sites in rabbits. Lack of effect of 17 beta-estradiol.
Gender differences in intima-media permeability to low-density lipoprotein at atherosclerosis-prone aortic sites in rabbits. Lack of effect of 17 beta-estradiol.
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DOI：
10.1161/01.atv.17.10.2150
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发表时间：
1997-10
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影响因子：
--
通讯作者：
D. Schwenke
中科院分区：
文献类型：
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作者：
D. Schwenke
绝经前的女性不会患冠心病，绝经前的非人类灵长类动物不会患上动脉粥样硬化，而动脉粥样硬化是导致冠心病的根本原因。雌激素被认为是女性这种保护的原因，这种保护的一部分是独立于对包括脂蛋白水平在内的危险因素的影响的。这项研究认为，低密度脂蛋白(LDL)对内膜-中层通透性降低可能是绝经前女性预防动脉粥样硬化和冠心病的原因，而且这种作用可能是由雌激素介导的。用0.5%胆固醇喂养8天的高胆固醇血症的雄兔和雌兔，测定其对低密度脂蛋白的内膜-中膜通透性。在高胆固醇饲养期间及之前的4周内，一半雌性兔的日粮中添加17β-雌二醇(4 mg/d)。雌性兔雌激素治疗不影响内膜-中膜对低密度脂蛋白的通透性。然而，腹主动脉和腹主动脉弓分支对低密度脂蛋白的通透性，雄兔分别比雌兔低43%和38%：(2.93+/-0.39微L/h/g，n=8)，vs6.28+/-0.86微L/h/g，(n=16)，P<；.001和4.69+/-0.28微L/h/g，(n=8)vs7.57+/-0.75微L/h/g，(n=16)，P<；0.02)。相比之下，在8个相对抵抗动脉粥样硬化的主动脉部位中，7个部位的内中膜对低密度脂蛋白的通透性在雄兔和雌兔之间没有差异。这些数据表明，与女性性别和雌激素相关的动脉粥样硬化的保护作用是由机制(S)介导的，而不是降低内膜-中层对低密度脂蛋白的通透性。
Premenopausal women are protected from coronary heart disease, and premenopausal nonhuman primates are protected from atherosclerosis, the underlying cause of coronary heart disease. Estrogen is thought to account for this protection in females, and part of this protection is independent of the effects on risk factors, including lipoprotein levels. This study considered the hypothesis that reduced intima-media permeability to low-density lipoproteins (LDL) may account for the protection from atherosclerosis and coronary heart disease in premenopausal females and that this effect might be mediated by estrogen. Intima-media permeability to LDL was determined in male and female rabbits made hypercholesterolemic by feeding them 0.5% cholesterol for 8 days. The diet of half of the female rabbits was supplemented with 17 beta-estradiol (4 mg/d) during cholesterol feeding and the preceding 4 weeks. Estrogen treatment in the female rabbits did not influence the intima-media permeability to LDL. However, intima-media permeability to LDL for branch sites of the abdominal aorta and aortic arch (regions highly susceptible to atherosclerosis) was 43% and 38% lower, respectively, in male rabbits than in female rabbits: (2.93 +/- 0.39 microL/h/g, (n = 8), vs 6.28 +/- 0.86 microL/h/g, (n = 16), P < .001, and 4.69 +/- 0.28 microL/h/g, (n = 8) vs 7.57 +/- 0.75 microL/h/g, (n = 16), P < .02). In contrast, intima-media permeability to LDL in 7 of 8 aortic sites relatively resistant to atherosclerosis did not differ between male and female rabbits. These data suggest that the protection from atherosclerosis associated with female sex and estrogen is mediated by mechanism(s) other than reduction in intima-media permeability to LDL.