Inhibition of rat adenocarcinoma metastases by "Staphylococcus aureus" protein A

Fischer F 344/CRBL female rats were injected intravenously with 10(6) syngeneic 13,762 adenocarcinoma cells, and daily doses of either 10 micrograms, 100 micrograms or 1 mg Staphylococcus aureus protein A were administered intraperitoneally on days 1 through 11. The animals were sacrificed on day 12, their lungs infused with Bouin's solution, and lung metastases counted. A significant reduction in the number of visible metastatic nodules was observed in the animals given 100 micrograms and 1 mg of Staphylococcus aureus protein A daily.