The influence of injection site upon the form of dye-dilution curves.

The validity of the serial compartment analysis of dye dilution curves was tested by injecting dye into the right auricle, pulmonary artery, a pulmonary vein and the aorta consecutively while sampling blood from the carotid artery. It was found that the serial compartment analogy is valid and that the lungs tire the largest volume in the series. In curves obtained by injecting into the pulmonary artery and sampling from the left auricle it was shown that under the conditions of the experiments, the lungs act like a single volume from which dye is washed out in exponential fashion.