CSF biomarkers, impairment of cerebral hemodynamics and degree of cognitive decline: An overview in different dementia subtypes

Abstract

the central actions of peripheric RAS components, an independent RAS exists in the brain. We have previously shown that RAS components such as angiotensin II, angiotensin-converting enzyme (ACE) and AT1 receptor are present in several brain regions in humans. Angiotensin II was found in the striatum, cortex and hippocampus in cellular localizations indicating a role as a regulatory peptide. It was increased in Alzheimer's disease (AD) patients. ACE and AT1 expression in cells were found to be also increased in AD brain. In addition, in aged controls, AD patients and in patients with vascular dementia, there was a prominent perivascular ACE and angiotensin II staining, probably pointing to an underlying microvascular pathology. ACE, angiotensin II and AT1 were also localized in human ocular tissues in various cells pointing to different function of RAS components on neuronal cells, vessels and vitreous humor homeostasis. Taken together, there is growing evidence that the central RAS is involved in the disease process of neurodegenerative disorders at many levels.