Inhibition of Serous Exudation and Tumor Cell Proliferation in Peritoneal Cavities of Mice Given Cortisone.

Abstract
Summary and Comment The results as a whole indicate that the treatment with cortisone impaired the growth of intraperitoneally implanted Sarcoma 180 cells, as was shown by morphological abnormalities in the tumor cells of treated animals, by a decrease in the number of tumor cells present in the peritoneal exudate, and by the lack or scarcity of serosal implants. This effect was not due to direct contact between cortisone and tumor cells, since i.p. treatment was not more efficient than s.c. injections. Furthermore, tumor cells of cortisone-treated mice grew freely when transferred into new hosts. Hence, it seems reasonable to suppose that the cortisone influenced the tumor cells only indirectly by changing their environment unfavorably. The essential change appeared to consist in a suppression of the serous exudate which is induced by the presence of tumor cells in the peritoneal cavity and constitutes a necessary condition for their growth and implantation. The scarcity or lack of serous fluid in spite of abundant growth of free tumor cells in the peritoneal cavity may be attributed to the well known suppressing action of cortisone on capillary permeability (13,14).