Proton NMR studies on ischemic rat brain tissue.

Area of Science:

• Biophysics
• Neuroscience
• Biochemistry

Background:

• Cerebral ischemia involves complex changes in brain tissue composition and water dynamics.
• Understanding water-macromolecular interactions is crucial for diagnosing and monitoring ischemic events.
• Nuclear Magnetic Resonance (NMR) relaxation times offer insights into these interactions.

Purpose of the Study:

• To investigate water-macromolecular interactions in ischemic rat brain tissue using NMR.
• To assess the utility of spin-lattice relaxation time (T1) and cross-relaxation time (TIS) in detecting cerebral ischemia.
• To correlate changes in relaxation times with water and electrolyte content alterations.

Main Methods:

• Measurement of spin-lattice relaxation time (T1) of water protons.
• Measurement of cross-relaxation time (TIS) between protein and water protons.
• Induction of ischemia via bilateral common carotid artery occlusion in stroke-prone spontaneously hypertensive rats.
• Quantification of water, sodium (Na), and potassium (K) content in brain tissues.

Main Results:

• Water and Na content increased, while K content and TIS values decreased following ischemic insults.
• TIS value changes were observed earlier than alterations in T1, water, and electrolyte content.
• T1 values remained unchanged until 180 minutes post-ischemia induction.

Conclusions:

• Cross-relaxation time (TIS) is a sensitive indicator for early detection of cerebral ischemia.
• NMR-based assessment of water-macromolecular interactions can reveal early structural changes in ischemic brain tissue.
• TIS measurements may provide a valuable tool for monitoring the onset and progression of ischemic events.