Related Experiment Video
Updated: Jul 25, 2026
Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors
Published on: June 7, 2016
Expression of angiotensin II AT2 receptor in the acute phase of stroke in rats
1Department of Pharmacology, Faculty of Medicine, National University of Singapore, Crescent, Singapore.
Abstract:
A male Wistar rat model of stroke (middle cerebral artery occlusion; MCAO) was used to study the angiotensin II (Ang II) receptor subtype 2 (AT2) gene expression by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining. After permanent occlusion of the middle cerebral artery (MCA), AT2 receptor gene expression was found to increase in the infarct cortex by 2.7-fold (1 day) and 1.7-fold (3 days), respectively. Positive AT2 immunostaining was also observed in the infarct area of the cerebral cortex. Apoptotic markers were detected in the necrotic area of the stroke cerebral cortex 1 day after MCAO. This demonstrated up-regulation of AT2 receptor may be involved in the apoptosis of tissue repair after stroke.
Insights
Stroke (middle cerebral artery occlusion; MCAO) in rats showed increased angiotensin II (Ang II) receptor subtype 2 (AT2) gene expression in the infarct cortex. This suggests AT2 receptor up-regulation may play a role in stroke-related tissue repair and apoptosis.
Area of Science:
- Neuroscience
- Molecular Biology
- Pathology
Background:
- Stroke, particularly ischemic stroke caused by middle cerebral artery occlusion (MCAO), is a leading cause of death and disability worldwide.
- The renin-angiotensin system (RAS) and its components, including angiotensin II (Ang II) and its receptors, are implicated in various physiological and pathological processes, including cardiovascular and cerebrovascular diseases.
- The role of specific Angiotensin II receptor subtypes, such as AT2, in the post-stroke environment remains incompletely understood.
Purpose of the Study:
- To investigate the gene expression profile of the angiotensin II receptor subtype 2 (AT2) in a rat model of ischemic stroke.
- To determine the temporal and spatial changes in AT2 receptor expression within the infarct core and surrounding tissue following middle cerebral artery occlusion (MCAO).
- To explore the potential association between AT2 receptor up-regulation and cellular processes like apoptosis in the context of stroke-induced brain injury.
Main Methods:
- Establishment of a male Wistar rat model subjected to permanent middle cerebral artery occlusion (MCAO) to induce ischemic stroke.
- Quantitative analysis of AT2 receptor gene expression using reverse transcription polymerase chain reaction (RT-PCR) at different time points post-MCAO.
- Localization and assessment of AT2 receptor protein expression via immunohistochemical staining in the affected cerebral cortex.
- Detection of apoptotic markers in the necrotic areas of the stroke-affected brain tissue.
Main Results:
- A significant up-regulation of AT2 receptor gene expression was observed in the infarct cortex, with a 2.7-fold increase at 1 day and a 1.7-fold increase at 3 days post-MCAO.
- Immunohistochemical staining confirmed the presence of AT2 receptors within the infarct area of the cerebral cortex.
- Apoptotic markers were detected in the necrotic cerebral cortex tissue 1 day after MCAO, coinciding with elevated AT2 receptor expression.
Conclusions:
- The findings demonstrate a marked increase in AT2 receptor gene and protein expression in the cerebral cortex following experimental stroke (MCAO).
- The up-regulation of the AT2 receptor in the infarct zone suggests its potential involvement in the cellular responses, including apoptosis, during the tissue repair process after stroke.
- Further research is warranted to elucidate the precise mechanisms by which AT2 receptor modulation influences stroke outcomes and to explore its therapeutic potential.
