Protamine-induced Cardiotoxicity Is Prevented by Anti-TNF-α Antibodies and Heparin

Background : We investigated the role of tumor necrosis factor [alpha] (TNF-[alpha]) in protamine-induced cardiotoxicity and the possibility of preventing or decreasing this effect by anti TNF-[alpha] antibodies and heparin.

Methods : Isolated rat hearts were perfused for 60 min with Krebs-Henseleit solution (KH). The control group was perfused with KH alone, the KH > protamine > KH group was treated from the 20th to the 40th minute with protamine, and the KH + anti-TNF > protamine + anti-TNF > KH + anti-TNF group was treated the same as the KH > protamine > KH group but with anti-TNF-[alpha] antibodies added throughout perfusion. The KH + heparin > protamine + heparin > KH + heparin group was treated the same as the KH > protamine > KH group but with heparin added to KH throughout perfusion. The KH > protamine > KH + heparin was perfused the same as the KH> protamine > KH group but with heparin added to KH for the last 20 min. Left ventricular (LV) function and coronary flow were measured every 10 min. TNF-[alpha] was measured in the coronary sinus effluent. Left ventricular TNF messenger RNA was determined in the control and KH > protamine > KH groups at baseline and after the 40-min perfusion.

Results : Protamine caused a significant decrease of peak systolic pressure and dP/dt (to 25% of baseline). Significant amounts of TNF-[alpha] in the effluent in the KH > protamine > KH group (102.3 +/- 15.5 pg/min) and TNF messenger RNA expression in left ventricular samples were detected. TNF-[alpha] was below detectable concentrations in the control, KH + anti-TNF > protamine + anti-TNF > KH + anti-TNF, and KH + heparin > protamine + heparin > KH + heparin groups. TNF-[alpha] concentrations correlated with depression of LV peak systolic pressure (r = 0.984;P = 0.01) and first derivate of the increase of LV pressure (r = 0.976;P = 0.001). Heparin improved LV recovery and decreased protamine-induced TNF-[alpha] release (KH > protamine > KH + heparin group).