Endotoxin, primarily found in the outer membrane of Gram-negative bacteria, is toxic to which of the following types of cells?

• A. Macrophages
• B. Neurons
• C. Muscle cells
• D. Erythrocytes

Answer: (A)

Verified step by step guidance

1. Understand what endotoxins are: Endotoxins are lipopolysaccharides (LPS) found in the outer membrane of Gram-negative bacteria. They are released when the bacteria die and the membrane breaks apart.
2. Identify the target cells of endotoxins: Endotoxins primarily interact with cells of the immune system, especially those involved in detecting and responding to pathogens.
3. Recall the role of macrophages: Macrophages are immune cells that engulf pathogens and release signaling molecules like cytokines in response to endotoxins, which can trigger inflammation and other immune responses.
4. Consider other cell types listed: Neurons, muscle cells, and erythrocytes (red blood cells) are not primarily involved in immune detection or response to endotoxins, so they are less likely to be the toxic targets.
5. Conclude that endotoxins are toxic mainly to macrophages because these cells recognize endotoxins and respond by releasing inflammatory mediators, which can lead to toxic effects.