31P spectroscopy in experimental embolic stroke: correlation with infarct size

Area of Science:

• Neuroscience
• Biomedical Engineering
• Radiology

Background:

• Stroke is a leading cause of death and disability worldwide.
• Accurate animal models are crucial for understanding stroke pathophysiology and testing therapies.
• Phosphorus magnetic resonance spectroscopy (31P MRS) offers insights into brain metabolism during ischemia.

Purpose of the Study:

• To establish and characterize a rat model of focal cerebral ischemia using microsphere embolization.
• To investigate the relationship between early metabolic changes and infarct size.
• To evaluate the utility of this model for stroke research and MRS interpretation.

Main Methods:

• Serial 31P nuclear magnetic resonance spectra were acquired from rat brains.
• Right internal carotid artery was embolized using microspheres.
• Brains were stained with 2,3,5-triphenyltetrazoline chloride to assess infarcts.
• Correlation analysis was performed between pH decline and infarct size.

Main Results:

• A narrow dosage range of microspheres influenced pH decline, mortality, and infarct size.
• A strong correlation (r2 = 0.76) was found between early pH decline and infarct size.
• The decline in pH at 20 minutes post-embolization was the best early predictor of infarct.

Conclusions:

• This microsphere embolization model effectively creates heterogeneous brain ischemia in rats.
• Early pH decline is a reliable marker for predicting infarct size in this stroke model.
• The model is valuable for evaluating stroke therapeutics and interpreting MRS data from ischemic brain regions.