In the hepatic acinus, which zone is most susceptible to toxin-induced injury?

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Multiple Choice

In the hepatic acinus, which zone is most susceptible to toxin-induced injury?

The most vulnerable region to toxin-induced injury is the centrilobular area surrounding the central vein. This zone has the highest activity of cytochrome P450 enzymes, so toxins that require metabolic activation to become harmful intermediates accumulate here. At the same time, it has relatively low oxygen tension, making hepatocytes more susceptible to damage from oxidative stress and to ischemic-like injury. A classic example is acetaminophen overdose, where NAPQI formation is greatest in this zone, leading to centrilobular necrosis. In contrast, the periportal (oxygen-rich) zone is more resistant to this pattern of injury, while the midzone lies between them.

The most vulnerable region to toxin-induced injury is the centrilobular area surrounding the central vein. This zone has the highest activity of cytochrome P450 enzymes, so toxins that require metabolic activation to become harmful intermediates accumulate here. At the same time, it has relatively low oxygen tension, making hepatocytes more susceptible to damage from oxidative stress and to ischemic-like injury. A classic example is acetaminophen overdose, where NAPQI formation is greatest in this zone, leading to centrilobular necrosis. In contrast, the periportal (oxygen-rich) zone is more resistant to this pattern of injury, while the midzone lies between them.

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