Intestinal transport mechanisms

Small intestine:

(A) Fluid absorption in primarily villus epithelial cells showing active transepithelial transport of sodium via apical membrane transporters (SGLT1, NHE3, and DRA), and the basolateral Na⁺/K⁺ ATPase with corresponding passive chloride and water flux.
(B) Fluid secretion in primarily crypt epithelial cells showing active transport of chloride from the basolateral side via the NKCC and apical chloride channels (CFTR, CaCC) with corresponding passive sodium and water flux.

Colon:

(C) Fluid absorption in both surface and crypt epithelial cells showing active transepithelial transport of sodium via apical membrane transporters and channels (eNaC, NHE3, and the sodium-driven short-chain fatty acid transporter [SMCT]).
(D) Fluid secretion in primarily crypt epithelial cells showing active transport of chloride from the basolateral side via the NKCC and apical chloride channels (CFTR, CaCC) with corresponding passive sodium and water flux.

SGLT1: sodium-glucose cotransporter 1 (SLC5A1); DRA: downregulated in adenoma chloride/bicarbonate exchanger (SLC26A3); NHE3: sodium-hydrogen exchanger 3; CFTR: cystic fibrosis transmembrane regulator; CaCC: calcium-activated chloride channels; NKCC: Na⁺/K⁺/Cl^- symporter 1 (SLC12A2); SMCT: sodium-coupled monocarboxylate transporter (SLC5A8); eNaC: epithelial sodium channel; SCFA: short-chain fatty acids.

Graphic 113255 Version 4.0

خرید پکیج

Intestinal transport mechanisms