The role of blood coagulability and axial streaming of erythrocytes in determining F cells-value and TPR.
Experiments were performed in anaesthetized and splenectomized dogs to influence the intravascular distribution of erythrocytes and plasma within the vascular bed. Blood volume was determined by double-isotope labelling of red cells and plasma. A significant decrease of F cells-value was found after posthaemorrhagic haemodilution and after haemodilution induced by homologous plasma. The administration of epsilon-amino caproic acid and bovine thrombin was followed by a significant increase of F cells-value. An interdependence of coagulability and F cells-value is suggested. The increase of haematocrit was followed by an increase of TPR, which, however, was only half of the value that would have been anticipated on the basis of the increase of viscosity when measured in normal-bore viscometers. This points to the possibility that blood flowing in the resistance vessels undergoes a certain spontaneous separation of cells and plasma and its haematocrit will be lower than in the large vessels. Cell separation in different organs having different haematocrit values and blood volumes probably affects total body haematocrit and F cells-value.
D000818:Animals; D001775:Blood Circulation; D001777:Blood Coagulation; D001810:Blood Volume; D004285:Dogs; D004912:Erythrocytes / Q000502:physiology; D006400:Hematocrit; D006470:Hemorrhage / Q000503:physiopathology; D013156:Splenectomy; D014655:Vascular Resistance