CFTRinh-172 (Synonyms: CFTR(inh)172, Cystic Fibrosis Transmembrane Conductance Regulator Inhibitor 172)

Ki: 0.3 to 5 μM for channel opening

The cystic fibrosis (CF) transmembrane regulator (CFTR) is a cAMP-activated Cl channel expressed in epithelial cells of the lung, intestine, pancreas, and other tissues, where it facilitates transepithelial fluid transport. CFTRinh-172 is a highly potent and selective CFTR inhibitor.

In vitro: CFTRinh-172 could reversibly inhibit CFTR short-circuit current in less than 2 minutes in a voltage-independent manner. Moreover, at concentrations fully inhibiting CFTR, CFTRinh-172 did not prevent elevation of cellular cAMP or inhibit non-CFTR Cl–channels, multidrug resistance protein-1, ATP-sensitive K+ channels, or a series of other transporters [2].

In vivo: A single ip injection of CFTRinh-172 (250 μg/kg) in mice reduced by more than 90% cholera toxin–induced fluid secretion in the small intestine over 6 hours. CFTRinh-172 may be useful in developing large-animal models of cystic fibrosis and reducing intestinal fluid loss in cholera and other secretory diarrheas [3].

Clinical trial: Up to now, CFTRinh-172 is still in the preclinical development stage.

Reference:
[1] Ma T, Thiagarajah JR, Yang H, Sonawane ND, Folli C, Galietta LJ, Verkman AS.  Thiazolidinone CFTR inhibitor identified by high-throughput screening blocks cholera toxin-induced intestinal fluid secretion. J Clin Invest. 2002 Dec;110(11):1651-8.