fibrin and Carcinoma-256--Walker

The intravenous injection of 131J-fibrinogen results in a selective accumulation of radioactivity in the solid Walker-256-carcinosarcoma of the rat. An effective anticoagulation with heparin beginning before administration of the radio-iodinated fibrinogen and continued up to the end of the experiment inhibits the enrichment of radioactivity. It is supposed that the radioactivity in the tumor is correlated to the deposition of 131J-fibrin. A clotting process in tumor transforms both fibrinogen and 131J-fibrinogen to fibrin resp. 131J-fibrin. This conversion is thrombin-dependent might be blocked by heparin. The tumor growth is not influenced by the presence of heparin.

Topics: Animals; Carcinoma 256, Walker; Female; Fibrin; Fibrinogen; Heparin; Iodine Radioisotopes; Rats

Tumor emboli were produced in lungs of Sprague-Dawley rats by i.v. injection of Walker 256 tumor cells into the tail vein. Tissues were examined by electron microscopy at periods from 30 sec to 72 hr after tumor injection. Two methods of conventional staining were used, in addition to immunoperoxidase techniques, with antifibrin antibodies produced in rabbits. Tumor cells accompanied by a platelet mass were seen in pulmonary arterioles at the earliest time period (30 sec). By conventional staining, small amounts of fibrin were detected within the platelet clumps by 5 min after inoculation. Periodicity indicating stable fibrin was not seen by this technique until 15 to 45 min. When peroxidase-labeled antibody was applied to tissue, sections showed fibrin-positive material at 30 sec, and periodicity of fibrin was detected by 5 min. Fibrin reached a maximum by both techniques at about 1 hr and disappeared, along with the platelets, at about 9 hr. When fibrinolysin was injected prior to the tumor cell inoculation, platelets and fibrin were either absent or present only in traces, and no stable fibrin was detected. These observations show that fibrin occurs very early in small amounts in association with tumor cell emboli, and is removed while the cells are still intravascular.

Topics: Animals; Blood Platelets; Carcinoma 256, Walker; Fibrin; Lung Neoplasms; Neoplasm Metastasis; Platelet Aggregation; Rats; Time Factors

Topics: Anemia, Hemolytic; Animals; Blood Cell Count; Blood Coagulation Disorders; Blood Urea Nitrogen; Carcinoma 256, Walker; Disseminated Intravascular Coagulation; Factor VIII; Female; Fibrin; Fibrinogen; Half-Life; Hematocrit; Hemoglobinometry; Hypercalcemia; Iodine Isotopes; Neoplasm Transplantation; Plasminogen; Platelet Adhesiveness; Rats; Serum Globulins; Thrombelastography; Transplantation, Homologous

After the intravenous injection of Walker 256 tumour cells into rats the platelet count decreased rapidly and remained low during the following period of observation. The platelet decrease was closely related to the number of cells injected. Intra-arterial tumour cell injections required a considerably higher tumour cell count to produce a comparable thrombocytopenia. Non-viable tumour cells and tumour cell fragments induced a similar decrease of circulating platelets. Neither viable tumour cells nor tumour cell fragments aggregated rat platelets in vitro. The presence of fibrin monomers in tumour cell injected animals suggested intravascular fibrin deposition; the plasma fibrinogen level, however, did not decrease significantly. Isotope studies using (51)Cr labelled platelets revealed a rapid disappearance of the platelets from the circulation and their trapping in the lung-the primary site of tumour cell lodgement. Dipyridamole and ancrod pretreatment did not influence the decrease of platelets and their accumulation in the lung after tumour cell injection. In contrast, heparin completely prevented the thrombocytopenia and the platelet trapping in the lung. From the present experiments it is concluded that embolic tumour cells lead to early endothelial damage, resulting in local thrombin formation with subsequent irreversible platelet aggregation.

Topics: Animals; Blood Cell Count; Blood Platelets; Carcinoma 256, Walker; Chromium; Chromium Isotopes; Dipyridamole; Embolism; Endothelium; Fibrin; Fibrinogen; Heparin; Injections, Intra-Arterial; Injections, Intravenous; Kidney; Liver; Lung; Neoplasm Metastasis; Platelet Adhesiveness; Rats; Spleen; Thrombin; Thrombocytopenia; Time Factors

Topics: Adhesiveness; Animals; Blood Platelets; Blood Vessels; Carcinoma 256, Walker; Embolism; Epithelium; Fibrin; Lymphoma; Microscopy, Electron; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms, Experimental; Neoplastic Cells, Circulating; Rats; Surface Properties

Topics: Animals; Blood Platelets; Capillaries; Carcinoma 256, Walker; Cell Aggregation; Cell Count; Fibrin; Fluorescent Antibody Technique; Goats; Histocytochemistry; Immune Sera; Immunodiffusion; Lung Neoplasms; Male; Methods; Microscopy, Electron; Neoplasm Metastasis; Neoplasms, Experimental; Pulmonary Artery; Rabbits; Rats; Staining and Labeling; Time Factors

Topics: Anemia, Hemolytic; Animals; Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelets; Blood Vessels; Carcinoma 256, Walker; Female; Fibrin; Fibrinogen; Hematocrit; Hemoglobins; Hypercalcemia; Iodine Isotopes; Plasminogen; Rats

Topics: Adenocarcinoma; Animals; Blood Platelets; Carcinoma 256, Walker; Cell Adhesion; Fibrin; In Vitro Techniques; Mammary Neoplasms, Experimental; Mice; Microscopy, Electron; Neoplasms, Experimental; Organoids; Platelet Adhesiveness; Pseudopodia; Rats; Thromboplastin

Topics: Aminocaproates; Aminocaproic Acid; Animals; Aprotinin; Blood Coagulation; Carcinoma 256, Walker; Carcinoma, Brown-Pearce; Fibrin; Fibrinolysin; Heparin; Hyperlipidemias; Lung Neoplasms; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms; Neoplasms, Experimental; Nitrogen Mustard Compounds; Pharmacology; Rabbits; Radiation Effects; Rats; Research

Topics: Animals; Blood Coagulation; Brain Neoplasms; Carbon Tetrachloride Poisoning; Carcinoma 256, Walker; Female; Fibrin; Heart Neoplasms; In Vitro Techniques; Kidney Neoplasms; Liver Neoplasms; Lung Neoplasms; Male; Mesentery; Neoplasm Metastasis; Neoplastic Cells, Circulating; Rats; Testicular Neoplasms; Wounds and Injuries