Uptake of 125I albumin by the endothelial surface of the isolated dog common carotid artery: effect of certain physical factors and metabolic inhibitors.

A study has been made, under transient conditions, of the uptake of 125I albumin by the endothelial surface of isolated dog carotid arteries. Effective rate constants were determined and the apparent activation energy was calculated to be about 13 kcal/mol in the range 25-37 degrees C. Label uptake was not significantly altered by the presence of 1 mmol/1 potassium cyanide or 10 mmol/1 iodoacetate in the incubating medium, or by the absence of substrate from it, consistent with the process being primarily passive. It appeared that the label entered the wall mainly by other routes than the endothelial inter-cell clefts.