Effect of aprotinin on in vitro cerebral endothelial ICAM-1 expression induced by astrocyte-conditioned medium

Pulmonary vascular resistance index during coronary artery bypass surgery with aprotinin

Low pulmonary vascular resistance index (PVRI) reflects favorable redundant pulmonary circulation following coronary artery bypass grafting with cardiopulmonary bypass surgery (CPB). This randomized study investigated whether aprotinin given in different modalities impacts PVRI after coronary artery bypass grafting. A total of 40 patients undergoing coronary artery bypass grafting were randomized to four groups according to aprotinin dose: (1) high dose, (2) early low dose, (3) late low dose, and (4) without aprotinin. Oxygenation index, pulmonary shunt, alveolar-arterial oxygen gradient and PVRI were determined. PVRI was calculated as the transpulmonary pressure gradient divided by cardiac index multiplied by 80. The results showed that PVRI remained relative low in all patients provided aprotinin regardless of treatment dosage; PVRI increased at 4 h after restarting ventilation after CPB in patients without aprotinin as compared with aprotinin (266 ± 137, 266 ± 115, 244 ± 86 vs. 386 ± 121, dynes-s-cm^-5, respectively, p = .047). Elevated postoperative PVRI was predictive for patients without aprotinin (AUC 0.668; SE 0.40; p < .0001; CI 0.590-0.746). There were no statistical differences in oxygenation index, pulmonary shunt or alveolar-arterial oxygen gradient between the groups. In conclusion, aprotinin maintains a low PVRI in elective patients with healthy lungs during CPB. We suggest that aprotinin maintains pulmonary arterial endothelial integrity.

Effects of Aprotinin on Gene Expression and Protein Synthesis After Ischemia and Reperfusion in Rats

Background— Reperfusion injury of ischemic myocardium has been attributed to neutrophil infiltration, inflammatory activation and cardiac necrosis/apoptosis. Serine protease inhibition with aprotinin is cardioprotective, but the mechanism is unknown.

Methods and Results— We studied aprotinin in a rat model of myocardial ischemia for 20 minutes and reperfusion for 20 minutes, 8 hours or 24 hours. Aprotinin (20 000 IU/kg) given 5 minutes before reperfusion significantly reduced leukocyte accumulation ( P <0.01), myocardial injury (determined by CK depletion, P <0.01) and myocyte apoptosis ( P <0.05) compared with vehicle treated rats. Differential gene expression analysis showed myocardial ischemia plus reperfusion increased expression of proinflammatory genes like P-selectin, E-selectin, intercellular adhesion molecule, tumor necrosis factor-α, tumor necrosis factor-α receptor, interleukin-6, monocyte chemoattractant protein-1, p53, and Fas (CD59). Aprotinin before reperfusion suppressed expression of these inflammatory genes. Finally, differential protein expression analysis demonstrated increased intercellular adhesion molecule-1, tumor necrosis factor-α, and p53 after myocardial ischemia plus reperfusion, and this effect was diminished by aprotinin.

Conclusions— We demonstrated myocardial ischemia plus reperfusion induced leukocyte accumulation, inflammation, gene expression, protein expression and finally tissue injury and showed aprotinin limiting reperfusion injury through each of these stages, even after 24 hours of reperfusion. This effect seems partly attributable to suppression of proinflammatory genes and leukocyte accumulation. This work casts further light on the complex signaling of ischemia and reperfusion.