Which of the following is not a mediator of inflammation
**Core Concept**
Inflammation is a complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The mediators of inflammation are chemical signals that promote or resolve the inflammatory response.
**Why the Correct Answer is Right**
The correct answer is a molecule that does not typically participate in the inflammatory response. For example, **histamine** is a mediator of inflammation released from mast cells, leading to increased vascular permeability and smooth muscle contraction. **Bradykinin** is another mediator that causes vasodilation and increases vascular permeability. **Leukotrienes** are lipid mediators produced by leukocytes, causing smooth muscle contraction and increased mucus production. However, **aldosterone** is a steroid hormone that regulates sodium and potassium balance in the body, and is not typically involved in the inflammatory response.
**Why Each Wrong Option is Incorrect**
**Option A:** **Histamine** is a mediator of inflammation, so this option is incorrect.
**Option B:** **Bradykinin** is a mediator of inflammation, so this option is incorrect.
**Option C:** **Leukotrienes** are mediators of inflammation, so this option is incorrect.
**Option D:** **Aldosterone** is not a mediator of inflammation, so this option is correct.
**Clinical Pearl / High-Yield Fact**
Be aware of the different types of mediators of inflammation, including chemical mediators (such as histamine and bradykinin), lipid mediators (such as leukotrienes), and cellular mediators (such as neutrophils and macrophages).
**Correct Answer:** D. Aldosterone