AJP - Heart and Circulatory Physiology, Vol 251, Issue 3 676-H680, Copyright © 1986 by American Physiological Society

ARTICLES

Hydraulic conductivity of venous endothelium as measured with a volume clamp method

F. F. Vargas, P. Sanabria, H. Osorio and C. Schulz

Hydraulic conductivity (Lp) of cava vein endothelium was obtained with a new method that measures fluid flow at constant volume. Dogs were anesthetized with pentobarbital sodium. A vessel segment was removed, cannulated, and hung free from a force transducer calibrated to measure weight. Hydraulic pressure difference drove fluid across the vessel wall. This fluid was washed out from the vessel surface by external perfusion, causing a weight loss that was transmitted to a Grass polygraph through the force transducer. Shifting the polygraph balance caused a voltage output which was used to activate a controller operating a microsyringe pump. By injecting fluid into the vessel lumen, this servomechanism counteracted weight changes and kept volume and pressure at a fixed level. Recording the volume injected allowed continuous monitoring of fluid flow. This avoided the problems caused by frequent pressure and volume resetting in previous methods. Fluid flow was a linear function of the applied pressure (r = 0.87). Lp was 0.91 +/- 0.05 (SD) X 10-7 cm X s-1 X cmH2O-1. This value was very similar to those in continuous capillaries and arterial endothelium.

This article has been cited by other articles:

				Y. Shou, K.-m. Jan, and D. S. Rumschitzki Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia Am J Physiol Heart Circ Physiol, December 1, 2006; 291(6): H2758 - H2771. [Abstract] [Full Text] [PDF]