Final answer:
Proton pump inhibitors reduce acid secretion by inhibiting the proton pumps in the parietal cells of the stomach, thereby lowering gastric acid production and helping to treat acid-related conditions. The correct answer is B. reduce acid secretion in the parietal cells.
Step-by-step explanation:
The mechanism of action of proton pump inhibitors is to reduce acid secretion in the parietal cells of the stomach. Antacids, H₂-receptor antagonists, and proton pump inhibitors are all used to manage conditions related to excess stomach acid. Proton pump inhibitors, such as Omeprazole (Prilosec), work by binding to the proton pumps in the parietal cells, effectively inhibiting them from secreting hydrochloric acid (HCl) into the stomach lumen.
This leads to a decreased production of gastric acid, thereby lowering the stomach pH and providing relief from conditions like GERD, ulcers, and Zollinger-Ellison syndrome which can be exacerbated by high levels of stomach acid.
Unlike H₂ blockers like ranitidine (Zantac) or famotidine (Pepcid AC), which block H₂ receptors in the stomach to reduce acid secretion, proton pump inhibitors directly inhibit the enzyme system responsible for acid secretion.
Proton pump inhibitors do not neutralize existing acid nor do they directly target Helicobacter pylori infections, which can be a cause of ulcers. Therefore, the correct answer to the question is that they reduce acid secretion in the parietal cells.