A patient with GERD is started on famotidine. H2 receptor antagonists inhibit gastric acid secretion by blocking histamine-mediated activation on which cell type?
- A Enterochromaffin-like (ECL) cells
- B G cells
- C Parietal cells ✓
- D Chief cells
Correct answer: C. Parietal cells
Explanation
H2 receptor antagonists (famotidine, ranitidine) competitively block histamine H2 receptors on parietal cells, reducing both basal and stimulated acid secretion. Histamine is released from ECL cells and acts on parietal cell H2 receptors. G cells secrete gastrin. Chief cells secrete pepsinogen. Blocking parietal cell H2 receptors is the direct mechanism.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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