AJP - Gastrointestinal and Liver Physiology, Vol 263, Issue 1 6-11, Copyright © 1992 by American Physiological Society
Increased lymphatic flux of hyaluronan from cat intestine during fat absorption
R. K. Reed, M. I. Townsley, V. H. Pitts, T. C. Laurent and A. E. Taylor
Department of Physiology, University of South Alabama, Mobile 36688.
During fat absorption, chylomicrons with sizes up to 5,000-10,000 A must
traverse an interstitium that has estimated pore sizes of 120-200 A to
reach the lacteals. The present experiments were performed to study the
behavior of the interstitial matrix component hyaluronan during fat
absorption from the intestine. Ileal segments were isolated and
autoperfused in pentobarbital-anesthetized cats. A postnodal lymphatic was
cannulated, and lymph flow, protein, and hyaluronan concentration in lymph
were determined. In group 1, a mixture of oleic acid and taurocholate was
infused into the ileal lumen, while in group 2 the animals were fed cream
overnight. In group 1, control lymph flow and hyaluronan concentration
averaged 53.3 +/- 16.0 (SD) microliters.min-1.100 g intestine-1 and 21.4
+/- 16.0 micrograms/ml, respectively. Administration of taurocholate and
oleic acid increased lymph flow and lymph hyaluronan concentration by 100
and 50%, respectively, resulting in a nearly three-fold increase in
hyaluronan flux. Subsequent increases in venous pressure increased lymph
flow and reduced hyaluronan concentration in lymph to less than 3
micrograms/ml. Hyaluronan flux remained approximately 2
micrograms.min-1.100 g intestine-1 independent of lymph flow. In group 2,
no lymph sample was available before administration of fat. Hyaluronan
concentration at control venous pressure was 19.3 +/- 6.7 micrograms/ml and
fell to 10 micrograms/ml at the highest lymph flow. Hyaluronan flux was
approximately 10 micrograms.min-1.100 g intestine-1 at the highest lymph
flow and venous pressure (P less than 0.05 compared with the same lymph
flow in group 1).(ABSTRACT TRUNCATED AT 250 WORDS)
