Effect of endotoxin on granulation tissue formation in rats.

Open wounds were incised in the dorsal skin of female Wistar rats. Solutions of Salmonella typhosa endotoxin (0.25 micrograms to 25 micrograms/ml saline) were applied 3 times a day on granulation tissue formed in the wounds. 5 days of treatment with the lowest endotoxin concentration resulted in 25% increase of the weight of the tissue, a more than 30% increase of DNA content and a 25% increase of hydroxyproline content in the tissue. Further elevation of these values could be obtained by increasing endotoxin concentration by tenfold or hundredfold but these changes were not very pronounced.