This study was carried out to investigate the effects of pentoxifylline and adenosine on the pulmonary injury induced by E. coli endotoxin. The counts of circulating neutrophils in peripheral blood and pulmonary sequestration of neutrophils after inje...
This study was carried out to investigate the effects of pentoxifylline and adenosine on the pulmonary injury induced by E. coli endotoxin. The counts of circulating neutrophils in peripheral blood and pulmonary sequestration of neutrophils after injection of endotoxin, endotoxin with pentoxifylline, or endotoxin with adenosine, additionally electron microscopy of the lungs were carried out.
To account the circulation neutrophils, six white rabbits were intravenously injected 4㎎/㎏ of E. coli 026 : B6 lipopolysaccharide, and then counted circulating neutrophils at 0, 1, 2, 4, and 8 hours after injections. Another six were injected 4㎎/㎏ of endotoxin simultaneously with 100㎎/㎏ of pentoxifylline (40㎎/㎏ at 0 hour and 20㎎/㎏ at 1, 2, and 4 hours after first injection), then neutrophils were counted at 0, 1, 2, 4, and 8 hours after injection of the endotoxin. The third six were injected 4㎎/㎏ of endotoxin simultaneously with 50㎎/㎏ of adenosine(20㎎/㎏ at 0 hour and 10㎎/㎏ at 1, 2, and 4 hours after first injection), also the neutrophils were counted at 1, 2, 4, and 8 hours after endotoxin injection. Neutrophilic pulmonary sequestration was counted at 8 hours after injection of endotoxin, endotoxin with pentoxifylline, or endotoxin with adenosine. Electron microscopy of the lungs was carried out at 1, 4, and 8 hours after injections in each group. The results were as follows:
The number of circulating neutrophils was markedly decreased at 1 hour after endotoxin injection and sustained until 8 hours after injection. In the pentoxifylline and adenosine injected groups, circulating neutrophils were decreased in number at 1 hour, however, nearly recovered at 8 hours after injections. Pulmonary sequestration of neutrophils was marked in endotoxin injected group. In contrast, endotoxin with pentoxifylline and endotoxin with adenosine injected groups demonstrated mild sequestration of the neutrophils. Ultrastructural changes of the lungs were swelling, formation of cytoplasmic projections, and seperation of the cytoplasm from the basement membrane in the endothelium, swelling of type Ⅱ pneumocytes, and interstitial edema appeared in pentoxifylline and adenosine injected groups.
According to the above results, it is concluded that pentoxifylline and adenosine inhibit pulmonary sequestration of the neutrophils in endotoxemia and suppress pulmonary injury induced by endotoxin.