Abstract
Experiments were performed to determine the distributionratio of the absorbed tumour cells in the internal mammary lymphatics and thoracic duct of rabbits following an intraabdominal administration of a suspension of Ehrlich ascites tumour cells. Thirty minutes after the administration, the lymph was obtained from main excreting lymphatic channels (the starting point of the internal mammary lymphatics) on either side adjacent to the sternum following the exposure of the pleural surface of the diaphragm, and simultaneously from the thoracic duct just above the level of the VIII th vertebra. The lymph was put into a R. B. C. pipette and diluted to 1: 100 with an acetogentian-violet solution and transferred to a counting chamber. As a result it was suggested that the tumour cells in the internal mammary lymphatics showed a higher absorptive distribution than in the thoracic duct.
In an attempt to determine the adequacy of the internal mammary lymph and thoracic duct lymph as a culture medium the respective lymphatic specimens were simultaneously studied with a phasecontrast microscope. The lymph was obtained from lymphatics and put into an incubator before it was observed. Morphological features were followed chronologically (Every 30 minutes,3,6, and 18 hours). The results revealed, I) tumour cells in the internal mammary lymphatics indicated no degenerative changes, and II) the thoracic duct containing tumour cells indicated various types of cellular degeneration. This finding become increasing marked. This is probably because of some digestive enzymes which are contained in the thoracic duct lymph. It may be interpreted from the above experiment that the thoracic lymph is possesed with a certain defensive action against cancer invasion, and the internal mammary lymphatics is possessed with a certain defensive force, being distributed in morphological arrangement against cancer invasion.
