Evidence for enhanced uptake of ATP by liver and kidney in hemorrhagic shock.

It has been shown that infusion of ATP-MgCl2 proved beneficial in the treatment of shock; however, it is not known whether this effect is due to improvement in the microcirculation or direct provision of energy or a combination of the above or other effects. To elucidate the mechanism of the salutary effect of ATP-MgCl2, we have now examined the in vitro uptake of ATP by liver and kidney of animals in shock. Rats were bled to a mean arterial pressure of 40 Torr and so maintained for 2 hrs. After the rats were killed, liver and kidney were removed and slices of tissue (0.3-0.5 mm thick) were incubated for 1 h in 1.0 ml of Krebs-HCO3 buffer containing 10 mM glucose, 5 mM MgCl2, and 5 mM [8-14C]ATP or 5 mM [8-14C]ADP, or 5 mM [8-14C]AMP, or 5 mM [8-14C]adenosine in 95% O2-5% CO2 and then homogenized. Tissue and medium samples were subjected to electrophoresis to separate and measure the various nucleotides. The uptake of [14C]ATP but not that of [14C]ADP or [14C]adenosine by liver and kidney slices from animals in shock was 2.5 times greater than the corresponding uptake by control slices. Thus, the beneficial effect of ATP-MgCl2 in shock could be due to provision of energy directly to tissue in which ATP levels were lowered.