Uptake of bleomycin adsorbed on to activated carbon particles by regional lymph nodes of the esophagus in dogs.

Two bleomycin (BLM)-containing agents (BLM-CH, BLM-SOL) were prepared, and the possible usefulness of BLM-CH in the targeting of chemotherapy for esophageal cancer was studied. BLM-CH is an agent in which BLM is adsorbed on to activated carbon particles, and BLM-SOL is an aqueous solution of BLM. BLM-CH or BLM-SOL was injected into the submucosa of the middle thoracic esophagus of 14 mongrel dogs under endoscopic control. Three days after the administration, regional lymph nodes, connective tissues, liver, lung and spleen were removed, and BLM in the specimens was measured. When BLM-CH was administered, BLM was demonstrated not only in the lymph nodes near the injection site but also in the cervical and abdominal ones. In contrast, BLM was not detected in any lymph nodes when BLM-SOL was administered. Light and electron microscopic observation showed that activated carbon particles diffused and were distributed in the lymph nodes. The latter findings also revealed their existence in the interstices of lymphatic tissues and macrophages. When BLM-CH was injected, BLM in the blood was significantly lower when compared with the results of BLM-SOL administration. The results obtained indicate that BLM-CH may probably become a useful tool in targeting chemotherapy for esophageal cancer.