AJP - Gastrointestinal and Liver Physiology, Vol 239, Issue 6 516-G523, Copyright © 1980 by American Physiological Society
Effect of luminal distension on intestinal transcapillary fluid exchange
D. N. Granger, P. R. Kvietys, N. A. Mortillaro and A. E. Taylor
The direct effects of luminal distension pressure on intestinal
transcapillary fluid exchange were studied in isolated autoperfused cat
ileum preparations. Intestinal lymph flow, lymphatic pressure,
lymph-to-plasma protein concentration ratio (L/P), blood flow, and
perfusion pressures were allowed to reach a steady state at different
luminal distension pressures (0-40 mmHg). Luminal distension was induced
using a nonabsorbable silicone solution, thereby eliminating an influence
of net water absorption. At a venous outflow pressure of 0 mmHg, lymph flow
and lymphatic pressure increased, whereas blood flow and L/P decreased as
luminal pressure was increased. The relationship between lymph flow, blood
flow, and venous pressure was acquired at luminal pressures of 0 and 20
mmHg. When luminal pressure was 0, lymph flow increased and blood flow
decreased progressively with venous pressure elevation; however, when
luminal pressure was 20 mmHg, lymph flow and blood flow were unaffected
until pressure exceeded 20 mmHg. The results of this study indicate that
luminal pressure elevation enhances transcapillary fluid exchange and
imposes a "waterfall" effect on the intestinal vasculature.
