Angiotensin-(1-7)/Mas axis integrity is required for the expression of object recognition memory

作者：Lazaroni Thiago L N; Raslan Ana Claudia S; Fontes Walkiria R P; de Oliveira Marilene L; Bader Michael; Alenina Natalia; Moraes Marcio F D; dos Santos Robson A; Pereira Grace S^*

来源：Neurobiology of Learning and Memory, 2012, 97(1): 113-123.

DOI：10.1016/j.nlm.2011.10.003

• Angiotensin-(1-7)
• Receptor Mas
• Object recognition memory
• AT1 receptor

It has been shown that the brain has its own intrinsic renin-angiotensin system (RAS) and angiotensin(1-7) (Ang-(1-7)) is particularly interesting, because it appears to counterbalance most of the Ang II effects. Ang-(1-7) exerts its biological function through activation of the G-protein-coupled receptor Mas. Interestingly, hippocampus is one of the regions with higher expression of Mas. However, the role of Ang-(1-7)/Mas axis in hippocampus-dependent memories is still poorly understood. Here we demonstrated that Mas ablation, as well as the blockade of Mas in the CA1-hippocampus, impaired object recognition memory (ORM). We also demonstrated that the blockade of Ang II receptors AT1, but not AT2, recovers ORM impairment of Mas-deficient mice. Considering that high concentrations of Ang-(1-7) may activate AT1 receptors, nonspecifically, we evaluate the levels of Ang-(1-7) and its main precursors Ang I and Ang II in the hippocampus of Mas-deficient mice. The Ang I and Ang II levels are unaltered in the whole hipocampus of MasKo. However, Ang-(1-7) concentration is increased in the whole hippocampus of MasKo mice, as well as in the CA1 area. Taken together, our findings suggest that the functionality of the Ang-(1-7)/Mas axis is essential for normal ORM processing.

• 出版日期2012-1