PPADS tetrasodiuma is a non-selective P2X receptor antagonist. PPADS tetrasodiuma blocks recombinant P2X1, -2, -3, -5 with IC₅₀s ranging from 1 to 2.6 μM. PPADS tetrasodiuma blocks native P2Y2-like (IC₅₀~0.9 mM) and recombinant P2Y4 (IC₅₀~15 mM) receptors. PPADS tetrasodiuma is an inhibitor of the reverse mode of the Na/Ca²⁺exchanger in guinea pig airway smooth muscle^[1][2]. In Vitro: PPADS tetrasodiuma (1-30 μM; 10-50 minutes) inhibits Na+/Ca2+ exchanger reverse mode (NCXREV) in a time- and concentration dependent manner^[2].
PPADS tetrasodiuma is effective at other native and recombinant P2XRs. At human P2XRs sensitivity to PPADS tetrasodiuma depended on the subtype and was highest at the hP2X1, -2, -3, -5, and -7Rs with an IC50 of ∼1–3 and ∼30 μM for the hP2X4R^[3]. In Vivo: PPADS tetrasodiuma (15-60 mg/100g body weight (BW); i.p.; every 12 hours for 8 days) inhibits glomerular mesangial cells (MC) proliferation without altering proliferation of non-MC in vivo in mesangial proliferative glomerulonephritis^[4].