Brain lactic acidosis and ischemic cell damage: 2. Histopathology

Area of Science:

• Neuroscience
• Cell Biology
• Pathology

Background:

• Brain ischemia can lead to severe cellular damage.
• Lactic acidosis is a common consequence of ischemia.
• The role of lactic acidosis severity in ischemic brain injury requires further clarification.

Purpose of the Study:

• To investigate the influence of severe tissue lactic acidosis on cortex morphology during incomplete brain ischemia.
• To determine if excessive lactic acidosis exacerbates structural alterations and leads to irreversible cellular damage.

Main Methods:

• Studied cortex morphology in fasted rats subjected to 30 min incomplete brain ischemia.
• Varied lactate production via preischemic intravenous infusions of saline or glucose.
• Examined brain tissue ultrastructure via glutaraldehyde fixation at 0, 5, and 90 minutes of recirculation.

Main Results:

• Saline-infused rats (lower lactate) showed discrete, reversible changes.
• Glucose-infused rats (higher lactate) exhibited severe, irreversible cellular damage, including chromatin clumping and cell sap changes.
• Excessive lactic acidosis correlated with exaggerated structural alterations and extensive damage.

Conclusions:

• Severe tissue lactic acidosis during brain ischemia exaggerates structural alterations.
• Excessive lactic acidosis leads to irreversible cellular damage.
• Findings offer an explanation for the low incidence of certain cellular changes previously considered hallmarks of ischemic injury.