Tamura K, Yamaguchi K, Kogo H
Department of Pharmacology, Tokyo University of Pharmacy & Life Science, Hachioji, Japan.
Life Sci. 2000 Mar;66(17):PL 259-64. doi: 10.1016/s0024-3205(00)00488-4.
The objective of this study was to elucidate a role of ovarian steroid hormones in the production of immunologic nitric oxide (NO) synthases in the female rat aorta in vivo. Aortic homogenates were analyzed by using western blot with isoform-specific antibodies against endothelial NOS (eNOS) and inducible NOS (iNOS). Two weeks after ovariectomy (OVX), rats (10-week-old) were treated with 17beta-estradiol (E2) and/or progesterone (P4) for 5 days, and aortae were obtained from these rats on the following day. OVX markedly increased the levels of iNOS protein in abdominal aorta, whereas treatment with E2 or a combination of E2 and P4 inhibited the induction of iNOS in the aorta. The present findings indicate that endogeneous estrogen negatively regulates the expression of iNOS in abdominal aorta, and suggest that changes in the levels of circulating estrogen may affect vascular function.
本研究的目的是阐明卵巢甾体激素在雌性大鼠主动脉中体内免疫性一氧化氮（NO）合酶产生中的作用。使用针对内皮型一氧化氮合酶（eNOS）和诱导型一氧化氮合酶（iNOS）的亚型特异性抗体，通过蛋白质免疫印迹法分析主动脉匀浆。卵巢切除（OVX）两周后，对10周龄大鼠用17β-雌二醇（E2）和/或孕酮（P4）处理5天，次日从这些大鼠获取主动脉。OVX显著增加腹主动脉中iNOS蛋白水平，而用E2或E2与P4联合处理可抑制主动脉中iNOS的诱导。目前的研究结果表明，内源性雌激素对腹主动脉中iNOS的表达起负调节作用，并提示循环雌激素水平的变化可能影响血管功能。
