APStracts 2:0208H, 1995.

Pulmonary vascular extraction and distribution of antipyrine with alveolar flooding. Cua, William O., Vivien Bower, Cheryl Tice, and Francis P. Chinard. Departments of Medicine and of Physiology, University of Medicine and Dentistry - New Jersey Medical School, Newark, New Jersey 07103

APStracts 2:0208H, 1995.

Transport characteristics of antipyrine(AP), 22Na+, and tritiated water (THO) were assessed in dog lungs by multiple-indicator-dilution experiments in vivo with anesthesia and in isolated perfused preparations before and after alveolar flooding. In controls, outflow patterns of AP and THO were nearly identical. In flooding, AP and THO patterns separated. THO upslopes decreased and mean (_) and modal (tmax) transit times increased as flooding increased; AP initial upslopes remained relatively unchanged but _ increased while tmax decreased. Patterns of 22Na+ were unchanged. The results indicate 22Na+ limitation at the endothelium, AP limitation only at the epithelium, no THO limitation. A mathematical model is based on axial as well as orthogonal distribution of AP and THO. With alveolar flooding, diffusional distance may be a limiting factor in this distribution.

Received 6 March 1995; accepted in final form 8 May 1995.
APS Manuscript Number H212-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 26 May 1995.