Q.7 Which molecule does not take part in inflammatory response?
(1) Dopamine
(3) Thromboxane
(2) Prostaglandin
(4) Leukotrienes
Dopamine does not take part in the inflammatory response. Among the options—Dopamine, Prostaglandin, Thromboxane, and Leukotrienes—only Dopamine is a neurotransmitter primarily involved in neurological functions, not the classic mediators of inflammation derived from arachidonic acid.
Option Analysis
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Dopamine: A catecholamine neurotransmitter that regulates mood, reward, and motor control in the brain. While it can modulate immune responses indirectly via receptors on immune cells, it is not a direct participant in the acute inflammatory cascade like eicosanoids.
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Prostaglandin: Lipid mediators from arachidonic acid via cyclooxygenase pathway; they cause vasodilation, pain, fever, and increased vascular permeability during inflammation.
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Thromboxane: Eicosanoids (mainly TxA2) that promote platelet aggregation, vasoconstriction, and leukocyte recruitment, amplifying inflammation and clotting at injury sites.
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Leukotrienes: Produced via lipoxygenase pathway; they drive chemotaxis (e.g., LTB4 attracts neutrophils), bronchoconstriction, and edema in inflammatory conditions like asthma.
The correct answer is (1) Dopamine.
Introduction to Inflammatory Response Molecules
The inflammatory response is a protective mechanism involving key signaling molecules like prostaglandins, thromboxanes, and leukotrienes, all derived from arachidonic acid metabolism. But which molecule does not take part in inflammatory response? This question tests core concepts in biochemistry and immunology, vital for exams like GATE Life Sciences.
Core Mediators in Inflammation
Prostaglandins (e.g., PGE2) and thromboxanes arise from the cyclooxygenase pathway, driving vasodilation, pain, and platelet activation. Leukotrienes, from the lipoxygenase pathway, promote immune cell chemotaxis and vascular leakage. These eicosanoids are hallmarks of acute inflammation.
Why Dopamine Stands Apart
Dopamine, unlike the others, functions mainly as a neurotransmitter in the brain’s reward and motor pathways. It lacks direct involvement in arachidonic acid-derived inflammation signaling, making it the molecule that does not take part in inflammatory response.
Exam Insights for GATE Life Sciences
For competitive exams, remember: eicosanoids (options 2-4) are inflammation staples, while dopamine is not. NSAIDs target prostaglandins/thromboxanes; leukotriene blockers treat asthma.
