IN VITRO STUDY OF TRANSENDOTHELIAL ALBUMIN TRANSPORT IN A STEADY STATE PIPE FLOW AT HIGH SHEAR RATES.

The present series of experiments represents an extension of the work of J. S. Polsley to higher shear rates. In this in vitro investigation, the transport of **1**3**1 I-albumin from serum to the wall of an excised dog common carotid artery has been measured under conditions of steady state pipe flow. The Reynolds numbers for these experiments ranged from 2,000 to 10,000 and this corresponds to transitional and fully turbulent flow conditions. The shear stress was determined by measuring both the flow rate and the pressure drop and was found to range from 50 to 500 dynes/cm**2. The associated friction factor was also determined. Comparable results were obtained using both serum and saline, and the general trend of these results is a gradual transition from laminar flow to a turbulent pipe flow with a corresponding wall roughness of epsilon /D approximately equal to 0. 05.