GI pharmacology I Flashcards
HCl is secreted by what cell?
parietal cell
mucus and bicarb are secreted by what cells?
superficial epithelial cells
histamine is secreted by what cell type?
ECL
gastrin is secreted by what cell type?
G cell
what is the key NT that promotes acid secretion?
Ach (direct and indirect regulation)
what is the neurocrine regulatory NT of mucus secretion?
Ach
what is the paracrine regulatory NT of mucus secretion?
PGs
what are the roles of PGs?
- mucus and bicarb secretion
- suppression of HCl secretion
- increased gastric blood flow
what are the antacid agents?
- sodium bicarbonate
- calcium carbonate
- magnesium hydroxide
- aluminum hydroxide
what are the adverse effects of sodium bicarbonate?
- metabolic alkalosis
2. excessive salt absorption
what are the adverse effects of calcium carbonate?
- acid rebound
2. gas / bloating
what are the adverse effects of magnesium hydroxide?
osmotic diarrhea
what are the adverse effects of aluminum hydroxide?
constipation
how do histamine blockers work?
- competitive inhibition of H2 receptors (highly selective)
- partial decrease in gastrin induced secretion of HCl
- partial block of muscarinic induced HCl secretion
what are the H2 blocker drugs?
- cimetidine (Tagemet)
- ranitidine (Zantac)
- nizatidine (Axid)
- famotidine (Pepcid)