The interaction of AB-680, a CD73 inhibitor, with NBTI, a nucleoside transporter inhibitor, on the adenosinergic control of atrial contractility

We found that AB-680, when added alone, did not affect the response to CPA. In turn, AB-680, when administered together with NBTI, was able to partially reverse the elevating effect of NBTI on the interstitial adenosine level. Nevertheless, the inhibitory action of AB-680 on the effect of NBTI appeared to be smaller than that of PSB-12379, another CD73 inhibitor investigated earlier in the same experimental model. We also found that DMSO interfered with our measurements to a lesser extent than the buffer recommended for <i>in vivo</i> studies. In addition, AB-680, when co-administered with NBTI (both dissolved in DMSO), reduced c_x (i.e. probably also the surplus interstitial adenosine) by at least half.