**Question:** An 82-year-old man has profound bleeding from a peptic ulcer and dies of hypovolemic shock. The liver at autopsy displays centrilobular necrosis. Compared to ble hepatocytes, the necrotic cells contain higher intracellular concentrations of which of the following?

A. Inorganic phosphate
B. Sodium
C. Lactate
D. Acetaminophen

**Core Concept:** Peptic ulcer bleeding can lead to hypovolemic shock and centrilobular necrosis in the liver due to hypoperfusion and hypoxia. Centrilobular necrosis is a specific type of liver cell injury that occurs in the centrilobular regions of the liver lobule.

**Why the Correct Answer is Right:** In this scenario, the necrotic cells contain higher intracellular concentrations of D. Acetaminophen. Acetaminophen (paracetamol) is a commonly used analgesic and antipyretic agent that can cause liver injury when taken in overdose. The mechanism involves cytochrome P450-dependent oxidative biotransformation and subsequent depletion of glutathione (GSH), leading to mitochondrial dysfunction and hepatocellular necrosis. In this case, the necrotic hepatocytes have higher concentrations of acetaminophen compared to healthy hepatocytes.

**Why Each Wrong Option is Incorrect:**

A. Inorganic phosphate: Centrilobular necrosis is not associated with changes in inorganic phosphate levels. Inorganic phosphate is a crucial mineral for cellular energy production and is involved in several cellular processes, but its concentrations are not relevant to the pathogenesis of centrilobular necrosis.

B. Sodium: Sodium concentrations are not related to centrilobular necrosis. Sodium regulation occurs in the kidneys, not in the liver, and centrilobular necrosis is not directly linked to sodium levels.

C. Lactate: Elevated lactate levels are more commonly associated with lactic acidosis, an entirely different clinical scenario. Centrilobular necrosis does not directly correlate with lactate concentrations in the liver tissue.

In summary, centrilobular necrosis in the context of peptic ulcer bleeding and hypoperfusion is linked to acetaminophen toxicity and not related to sodium, phosphate, or lactate concentrations.