急性脑梗死患者血小板磷酸二酯酶活性变化及共影响因素研究

Changes of platelet phosphodiesterase activity in patients with acute cerebral infarction and its influencing factors

目的观察急性脑梗死患者衄小板磷酸二酯酶（PDE）亚型活性变化，拆；讨影响其因素。方法对30例急性脑梗死患者分别于发病第1、4、8、15天检测血小板PDE活性、环核苷酸含量、[Ca2＋]i水平，并以10例年龄相当的健康体检者为正常对照。结果与对照组比较，急性脑梗死患者发病第1、4、8天时血小板PDE2、PDE3亚型活性降低，环腺苷酸（cAMP）含量降低，胞浆[Ca2＋]i水平升高，差异均有统计学意义俨〈0．05）；PDE5亚型活性及环鸟苷酸（cGMP）含量则无明显变化。相关分析显示，PDE2活性、PDE3活性与cAMP含量、[Ca2＋]i水平均无相关关系，cAMP含量与[Ca2＋]i水平问呈负相关关系（R2=0．921，P〈0．05）。结论脑梗死急性期血小板胞浆cAMP含量降低，[Ca2＋]i水平升高，血小板处于活化状态；血小板PDE2、PDE3通过降低活性、减轻cAMP降低程度、抑制血小板活化而在脑梗死急性期发挥保护作用。

Objective To observe the changes of activities of platelet phosphodiesterase （PDE） subtypes in patients with acute cerebral infarction, and explore their influencing factors. Methods The platelet PDE activity, cyclic nucleotide level and [Ca2＋]i concentration of 30 patients with a.cute cerebral infarction were detected on the 1th 4th 8th and 15th d of onset. Ten healthy individuals of the same age ranges were chosen as control group. Results On the 1th 4th and 8th d of onset, as compared with those in the healthy individuals, the activities of platelet PDE2 and PDE3 and the level of cyeilic adenosine monophosphate （cAMP） were obviously decreased, and the [Ca2＋]i level was significantly increased in patients with acute cerebral infarction （P〈0.05）; while the PDE5 activity and cyclic gnanosine monophosphate （cGMP） level in patients with acute cerebral infarction did not change obviously. [Ca2＋]i was linearly correlated with cAMP （R2=-0.921, P〈0.05）; however, the activities of PDE2 and PDE3 showed no correlation with both levels of [Ca2＋]i and cAMP. Conclusion Decreased cAIviP level and increased [Ca2＋]i concentration are noted in patients with acute cerebral infarction, and the platelet is activated at this time points. Platelet PDE2 and PDE3 play protect roles in acute cerebral infarction through decreasing their activities, slowing the cAMP decreased level and inhibiting the activity of platelet.