Biochem/physiol Actions

DCPIB is a potent inhibitor of the volume-sensitive anion channel (VSAC). IC₅₀ = 4.1µM ) versus ICl,_swell in calf pulmonary artery endothelial (CPAE) cells. DCPIB does not inhibit CPAE cell I_Cl,_Ca; hCFTR; nor guinea pig I_Cl,PKA, I_Kr, I_Ks,I_Kl, I_Na and I_Ca. DCPIB inhibition is reversible and voltage independent. ICl,_swell is believed to be important in cardiovascular function. Studies have been limited by the lack of specific ligands.

DCPIB is a reversible and highly selective volume-regulated anion channel (VRAC or VSOAC) blocker (by 50/98.7% of hypotonic solution-induced Cl current or I_Cl,swell at 4.1/10 µM in calf pulmonary artery endothelial (CPAE) cells vs. 4.1% inhibition of Ca²⁺-activated I_Cl,Ca or CaCC at 10 µM) with little or no inhibition against hminK (I_Ks), hCFTR, hCLC-1/2/4/5, rCLC-K1, hKv1.5, hKv4.3, HERG (≤5.9% at 10 µM; transpected xenopus oocytes), nor I_Ks, I_Kr, I_K1, I_Na, I_Ca, or I_Cl,PKA in isolated guinea pig cardiomyocytes. When applied in rats in vivo (10 mg/kg ip.), DCPIB is shown to protect against myocardial ischaemia/reperfusion injury.