The hematopoietic protective effect of bacterial endotoxin prior to nitrogen mustard in the mouse and dog.

Bacterial endotoxin was given to mice 24 h before nitrogen mustard (HN2). Total nucleated cells and peroxidase positive cells/humerus were significantly higher during the recovery phase in endotoxin-treated mice compared to controls given HN2 alone. Endotoxin was also given prior to HN2 in dogs, and a suggestive hematopoietic protective effect was found.