目的：观察４月龄自发性高血压大鼠（ＳＨＲ）心脏α１肾上腺素受体（α１－ＡＲ）及其３种亚型分布与功能的改变。方法：采用离体左心房收缩功能实验和放射配体结合实验。结果：ＳＨＲ与Ｗｉｓｔａｒ大鼠相比，（１）心脏α１－ＡＲ总密度无显著变化，但对去甲肾上腺素（ＮＥ）的敏感性显著增加（Ｐ＜００５）；（２）心脏α１Ａ－ＡＲ数量无明显改变，而α１Ｂ－ＡＲ增加，α１Ｄ－ＡＲ减少，但３种亚型受体在介导ＮＥ所致心肌正性变力效应中均无显著改变。结论：提示ＳＨＲ心脏α１－ＡＲ对ＮＥ敏感性的增加可能与受体后信号转导和／或兴奋收缩耦联的增强有关，其中尤以α１Ｄ－ＡＲ最为明显 Objective: To observe the changes of the distribution and function of α1-adrenergic receptor (α1-AR) and its three subtypes in 4-month-old spontaneously hypertensive rats (SHR). Methods: Isolated left atrial systolic function test and radioligand binding assay. Results: Compared with Wistar rats, there was no significant change in total α1-AR concentration in SHR, but the sensitivity to norepinephrine was significantly increased (P <005); (2) There was no significant change in the number of -AR and the increase of α1B-AR and the decrease of α1D-AR. However, there was no significant change in all three subtypes of receptor mediated by NE-induced positive cardiac muscle. CONCLUSIONS: The increased sensitivity of NE to SH in the heart of SHR may be related to the enhancement of post-receptor signal transduction and / or excitatory-contractile coupling, especially α1D-AR