The renin-angiotensin system in the human brain

The renin-angiotensin system is a hormonal system that regulates blood pressure. In addition to controlling blood pressure, this hormonal system interacts in a complex way with the dopaminergic system. This interaction is of particular interest in the context of neurodegeneration, notably Parkinson's disease.

The main protein of the renin-angiotensin system, angiotensin II, acts via two main G protein-coupled receptors, AT1 and AT2. Activation of the AT1 receptor is associated with pro-oxidative and pro-inflammatory effects. These effects promote oxidative stress and neurological inflammation, which are strongly implicated in the pathogenesis of Parkinson's disease. Conversely, activation of the AT2 receptor limits oxidative stress and neurological inflammation.

A dysregulation of the renin-angiotensin system, more specifically an imbalance in favor of the pro-oxidative/pro-inflammatory axis, has been observed in several animal models and patients with Parkinson's disease. It has been correlated with accelerated progression of dopaminergic neuron degeneration.  

Activation of the anti-oxidative axis by the AT2 receptor or inhibition of the pro-oxidative axis appear to be important therapeutic strategies in the fight against Parkinson's disease.

In conclusion, the renin-angiotensin system plays a crucial role in the regulation of neurodegenerative processes. It could be a promising target for the development of therapeutic strategies aimed at attenuating the progression of Parkinson's disease.