Dysregulation of NHE3 was specific to LPA, and insulin and cholera toxin were able to stimulate and inhibit NHE3, respectively, in both wild-type and Lpar5<sup>ΔIEC</sup> mice.
Cholera toxin (CT) causes severe diarrhea by increasing intracellular cAMP leading to a PKA-dependent increase in Cl<sup>-</sup> secretion through CFTR and decreased Na<sup>+</sup> absorption through inhibition of Na<sup>+</sup>/H<sup>+</sup> exchanger 3 (NHE3; also known as SLC9A3).