Reduction of Granulocyte-Mediated Lung Injury in Canine Cardiopulmonary Bypass by Anisodamine Infusion

Summary The effect of infusing the M-cholinergic receptor blocker anisodamine during cardiopulmonary bypass (CPB) on granulocyte-mediated lung injury was evaluated in sixteen dogs undergoing CPB for 120 min with the aorta crossclamped for 90 min. The treated dogs (n = 8) received a total dose of 15 mg/kg anisodamine hydrochloride before and during CPB whereas the controls (n = 8) received saline only. A significantly reduced sequestration of granulocytes in the lungs was found in the treated dogs as indicated by a lower right-to-left atrium granulocyte gradient 15 minutes after pulmonary recirculation during CPB (p < 0.05) and less granulocyte accumulation in the lung capillaries after CPB, as shown by histological examination (p < 0.01). Moreover, oxygen free radical release as indicated by plasma malondialdehyde concentrations was significantly lower (p < 0.05) in the treated dogs than in the controls towards the end of CPB. Finally, a significantly reduced lung-water content was found 30 min after CPB in the treated dogs as compared with the controls (p < 0.01). These results suggest that anisodamine administration in this experimental model significantly inhibits pulmonary granulocyte sequestration in CPB and the consequent lung injury induced.