Effects of ovariectomy and 17β-oestradiol replacement on [Ca2+]i in female rat cardiac myocytes
Effects of ovariectomy and 17β-oestradiol replacement on [Ca2+]i in female rat cardiac myocytes
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DOI：
10.1046/j.1440-1681.2003.03864.x
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发表时间：
2003-07-01
影响因子：
2.9
通讯作者：
Kotsanas, G
中科院分区：
文献类型：
--
作者：
Curl, CL;Wendt, IR;Kotsanas, G
1. 本研究探讨了卵巢切除（OVX）和17 - β -雌二醇替代对大鼠新分离心肌细胞[Ca(2+)](i)的影响。用胶原酶酶切法从sham、OVX和OVX + 17 β -雌二醇替代雌性大鼠心脏中分离心肌细胞。使用Ca（2+）敏感染料fura-2测量了[Ca(2+)](i)响应于不同细胞外[Ca(2+)]的变化，每个细胞的收缩反应被测量为细胞缩短。三组细胞外[Ca(2+)]升高导致[Ca(2+)](i)升高。与假手术组和17 β -雌二醇替代的OVX组相比，OVX组细胞的峰值[Ca(2+)](i)和瞬态Ca（2+）振幅显著增加（P < 0.01）。OVX细胞Ca（2+）瞬态衰变的时间过程明显快于假手术细胞和17 -雌二醇替代细胞（P < 0.02）。此外，OVX细胞松弛至50%的时间显著快于假手术细胞和17 -雌二醇细胞（P < 0.01），缩短程度显著大于假手术细胞（P < 0.04）。这些数据表明，OVX雌性大鼠心肌细胞与完整的和17β -雌二醇替代的OVX雌性大鼠心肌细胞相比，在峰值[Ca(2+)](i)和Ca（2+）瞬态振幅上存在明显差异。这表明雌激素可能在限制Ca（2+）进入心肌细胞中发挥长期作用。
1. The present study investigated the effects of ovariectomy (OVX) and 17beta-oestradiol replacement on [Ca(2+)](i) in rat freshly isolated cardiac myocytes.2. Myocytes were isolated from the hearts of sham, OVX and OVX + 17beta-oestradiol-replaced female rats by enzymatic digestion with collagenase. Changes in [Ca(2+)](i) in response to varied extracellular [Ca(2+)] were measured using the Ca(2+)- sensitive dye fura-2, with the contractile responses of each cell measured as cell shortening.3. Increasing extracellular [Ca(2+)] resulted in increased [Ca(2+)](i), in all three groups. Peak [Ca(2+)](i) and the amplitude of the Ca(2+) transient were significantly greater (P < 0.01) in cells from OVX animals compared with cells from both sham and 17 beta-oestradiol-replaced OVX animals.4. The time-course of decay of the Ca(2+) transient was significantly faster (P < 0.02) in OVX cells compared with both sham and 17beta-oestradiol-replaced cells. In addition, time to 50% relaxation was significantly faster (P < 0.04) and extent of shortening significantly greater (P < 0.01) in OVX cells than in either sham or 17beta-oestradiol cells.5. These data demonstrate clear differences in peak [Ca(2+)](i) and the amplitude of the Ca(2+) transient between OVX female rat cardiac myocytes compared with intact and 17beta-oestradiol-replaced OVX female rat cardiac myocytes. This suggests that oestrogen may play a long-term role in limiting Ca(2+) entry into the cardiac myocyte.