Vasoactive amine, involved in inflammation is –
**Core Concept**
Histamine is a vasoactive amine that plays a crucial role in the inflammatory response. Released from mast cells, it causes vasodilation, increases vascular permeability, and attracts leukocytes to the site of inflammation.
**Why the Correct Answer is Right**
Histamine exerts its effects by binding to specific receptors on the surface of target cells. It primarily acts through the H1 receptor to cause vasodilation and increase vascular permeability, leading to the characteristic symptoms of inflammation, such as redness, swelling, and warmth. Additionally, histamine stimulates the release of other chemical mediators, including leukotrienes and prostaglandins, which further contribute to the inflammatory response.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because serotonin is primarily involved in regulating mood, appetite, and sleep, rather than inflammation.
**Option B:** This option is incorrect because bradykinin is a peptide involved in the kinin-kallikrein system, which contributes to vasodilation and increased vascular permeability, but it is not a vasoactive amine.
**Option C:** This option is incorrect because prostaglandins are lipid compounds that mediate inflammation and pain, but they are not vasoactive amines.
**Clinical Pearl / High-Yield Fact**
Histamine is a key player in allergic reactions, including anaphylaxis, and its antagonists are used to treat conditions such as allergic rhinitis and asthma.
**Correct Answer:** D. Histamine.