Objectives

To explore effects of the brain renin-angiotensin system (RAS) on cognition.

Design

Systematic review of experimental (non-human) studies assessing cognitive effects of RAS peptides angiotensin-(3–8) [Ang IV] and angiotensin-(1–7) [Ang-(1–7)] and their receptors, the Ang IV receptor (AT4R) and the Mas receptor.

Results

Of 450 articles identified, 32 met inclusion criteria. Seven of 11 studies of normal animals found Ang IV had beneficial effects on tests of passive or conditioned avoidance and object recognition. In models of cognitive deficit, eight of nine studies found Ang IV and its analogs (Nle¹-Ang IV, dihexa, LVV-hemorphin-7) improved performance on spatial working memory and passive avoidance tasks. Two of three studies examining Ang-(1–7) found it benefited memory. Mas receptor removal was associated with reduced fear memory in one study.

Conclusion

Studies of cognitive impairment show salutary effects of acute administration of Ang IV and its analogs, as well as AT4R activation. Brain RAS peptides appear most effective administered intracerebroventricularly, close to the time of learning acquisition or retention testing. Ang-(1–7) shows anti-dementia qualities.

中文翻译：

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血管紧张素 IV 和血管紧张素-(1-7) 的认知益处：实验研究的系统回顾

 目标

探讨大脑肾素-血管紧张素系统（RAS）对认知的影响。

 设计

对评估 RAS 肽血管紧张素-(3-8) [Ang IV] 和血管紧张素-(1-7) [Ang-(1-7)] 及其受体 Ang 认知影响的实验（非人类）研究进行系统回顾IV 受体 (AT4R) 和 Mas 受体。

 结果

在确定的 450 篇文章中，有 32 篇符合纳入标准。对正常动物进行的 11 项研究中，有 7 项发现 Ang IV 对被动或条件性回避和物体识别测试具有有益作用。在认知缺陷模型中，九项研究中有八项发现 Ang IV 及其类似物（Nle ¹ -Ang IV、dihexa、LVV-hemorphin-7）可改善空间工作记忆和被动回避任务的表现。三项研究 Ang-(1-7) 的研究中有两项发现它有益于记忆。一项研究表明，Mas 受体的去除与恐惧记忆的减少有关。

 结论

认知障碍研究表明，急性给予 Ang IV 及其类似物以及 AT4R 激活具有有益作用。脑 RAS 肽似乎在接近学习获取或保留测试时间的脑室内施用最有效。 Ang-(1–7) 显示出抗痴呆特性。