中文摘要：

阿尔采末病（AD）是一种中枢神经系统退行性疾病，为最常见的痴呆类型。磷酸二酯酶包括一组水解细胞内第二信使环磷酸腺苷和（或）环磷酸乌苷的酶，已证实磷酸二酯酶抑制剂（PDE-s）对AD动物模型有积极的作用，如PDE4-I咯利普兰、PDE5-I西地那非。本文对PDE—Is改善AD认知功能及其作用机制作一综述，旨在为后续研发新的PDE-Is用于AD的治疗提供思路。

英文摘要：

Alzheimer＇ s disease is a neurodegenerative disorder of the central nervous system, which is the most common type of dementia. Phosphodiesterase （PDE） are enzymes that can hydrolyze the second messenger molecules cyclic adenosine monophosphate/cyclic guanosine monophosphate. It has been demonstrated that PDE inhibitors may improve memory function in animal models of AD, such as PDE4 inhibitor rolipram and PDE5 inhibitor sildenafil. This article reviewed the cognitive function and its possible mechanism of PDE inhibitors on AD, in order to provide ideas for the future research of new PDE inhibitors for the treatment of AD.