Experimental inhibition of protamine cardiotoxicity by prostacyclin

Twelve animals (26 +/- 5 kg) were subjected to the study. In this experimen tal study, the authors used prostacyclin to inhibit the toxic metabolite re lease during protamine administration. Animals were divided into two equal groups. Six animals received prostacyclin (the prostacyclin group), and the other six animals did not receive any additional treatment (the control gr oup). All cardiac output and biochemical measurements were evaluated at baseline; before cardiopulmonary bypass; and at 5, 30, and 60 minutes after protamin e administration. The measured cardiac index showed that the hearts treated with prostacyclin had satisfactory preservation of left ventricular functi on. Metabolic and biochemical data showed that the tumor necrosis factor level was raised significantly in the control group (20.75 +/- 2.2 in the control group and 13.75 +/- 2.5 pg/mL in the prostacyclin group). Also, E and P se lectin levels were elevated in the control group, but this change was less marked in the prostacyclin group. In addition, the intracellular adhesion m olecule-1 (ICAM-1) level was significantly higher in the control group than in the prostacyclin group (9.26 +/- 2.13 in the control group and 5.13 +/- 1.66 ng/mL in the prostacyclin group). The authors observed that prostacyclin inhibited the toxic mediator release during heparin reversal with protamine. This inhibition is one way of prot ecting the myocardium reserves from protamine cardiotoxicity.