论文部分内容阅读
采用电驱动离体大鼠左心耳收缩功能实验研究三种亚型α１－肾上腺素受体（ＡＲ）激动时对β－ＡＲ介导正性变力效应的影响． 结果发现，ＲＳ１７０５３（选择性拮抗α１Ａ－ＡＲ）或ＷＢ４１０１（选择性拮抗α１Ａ－和α１Ｄ－ＡＲ）可使去甲肾上腺素（ＮＥ）的累积浓度－收缩效应曲线（ＣＲＣ）显著左移；在ＢＭＹ ７３７８（选择性拮抗α１Ｄ－ＡＲ）和ＲＳ１７０５３ 存在下，ＮＥ仅激动α１Ｂ－和β－ＡＲ，其ＣＲＣ较单独激动β－ＡＲ 时显著左移；在ＷＢ４１０１ 和去氧肾上腺素（Ｐｈｅ）同时存在下（仅激动α１Ｂ－ＡＲ），异丙肾上腺素（Ｉｓｏ）的ＣＲＣ较对照显著左移；用ＢＭＹ ７３７８ 阻断α１Ｄ－ＡＲ后，ＮＥ的ＣＲＣ不发生明显的偏移；用ＲＳ１７０５３ 和螺哌隆阻断α１Ａ－和α１Ｂ－ＡＲ，用Ｐｈｅ 仅激动α１Ｄ－ＡＲ 时，对Ｉｓｏ 的ＣＲＣ也无影响． 结果说明在大鼠左心耳α１Ａ－ＡＲ抑制，α１Ｂ－ＡＲ 增强，而α１Ｄ－ＡＲ则不参与对β－ＡＲ 介导正性变力效应的调节．
The effects of three subtypes of α1-adrenergic receptor (AR) agonist on β-AR-mediated positive force were investigated by using the left atrial appendage contractile function in isolated rat hearts. As a result, it was found that the cumulative concentration-contraction effect (CRC) curve of norepinephrine (NE) was significantly shifted to left by RS17053 (selective antagonism of α1A-AR) or WB4101 (selective antagonism of α1A- and α1D-AR) NE only agonized α1B- and β-AR in the presence of 7378 (selective antagonism of α1D-AR) and RS17053, with a significant shift of CRC to that of β-AR alone; in the presence of WB4101 and phenylephrine (Phe) (Only agonized α1B-AR), isoproterenol (Iso) CRC significantly left shifted compared with the control; with BMY 7378 blocking α1D-AR, NE CRC no significant shift; with RS17053 and spiperone resistance Isolation of α1A- and α1B-AR, with Phe only agonized α1D-AR, Iso CRC also had no effect. The results indicate that α1A-AR inhibition in the left atrial appendage of the rat increases α1B-AR, whereas α1D-AR does not participate in the regulation of β-AR-mediated positive force.