With better understanding of pathogenic mechanism of secretory diarrhea, inhibitors of intestinal chloride channels represent promising drug candidates to reduce intestinal fluid loss in diarrhea. Several classes of small-molecule CFTR and CaCC inhibitors have been identified and demonstrated to effectively reduce fluid loss in mouse models of secretory diarrhea (10). However, the precise mechanism by which chloride channels are regulated has yet to be fully elucidated. It is likely that many mechanisms are involved in the regulation of CFTR activity such as cAMP-dependent protein kinase A (PKA), protein kinase C (PKC), type II isotype of cGMP dependent protein kinase, tyrosine kinase and AMP-activated protein kinase (AMPK) (11). For the regulation of CaCC activation, it has been shown that CaCC activity can be modulated by intracellular Ca2+, calmodulin-dependent protein kinase CaMKII, and cGMP-dependent protein kinase (12). However, the information regarding the role of nuclear receptors in the regulation of chloride channels, especially CFTR and CaCC, is still limited. Therefore, it is interesting to understand the molecular mechanisms that regulate the activity and expression of chloride channels since they may provide excellent targets for the treatment of secretory diarrhea.