The effects of E. coli endotoxin on the tubal mucosa of the rabbit. A scanning electron microscopic study.

E. Coli endotoxin (5 mg/ml) was injected into the lumen of the right fallopian tube of 25 rabbits. The left tubes, injected with saline, served as controls. The luminal surface of the epithelium of the oviducts was examined by a scanning electron microscope at various intervals after the injection. The damage that was caused by the endotoxin, was found to be maximal by 24 hours after injection. The damage was comprised of adhesions of shortened and swollen cilia and smoothened appearance of the secretory cells due to shortening and swelling of the microvilli. In some areas the epithelium was denuded of cilia. A relative rapid process of repair of the epithelium begins thereafter and by 72 hours, restoration of normal architecture of the mucosa was almost completed. The contralateral control tubes were not affected by the endotoxin. The possible influence of local gram negative bacterial infections, liberating large amounts of endotoxin,on the reproductive capacity is discussed.