Albumin to ascites: demonstration of a direct pathway bypassing the systemic circulation

Abstract

A B S T R A C T The transport of plasma albumin and newly made albumin into ascitic fluid was studied in eight patients with cirrhosis and ascites. The thoracic duct was cannulated in two patients and lymph collected over a period of 2 hr. Simultaneously albumin-WI and carbonate-'4C were injected intravenously. The albumin-131I measured the transfer of plasma albumin into ascites and into thoracic duct lymph. The carbonate-`C, by labeling newly formed albumin, permitted the estimation of the transfer of newly formed albumin into plasma, ascites, and lymph.If the newly synthesized albumin entering ascites and thoracic duct lymph is delivered initially into the plasma, then the ratios of the albumin-1C and -l1`I in ascites and lymph compared with the content of albumin-1`C and -"'I in plasma would be identical. However, if some newly formed albumin is delivered directly into ascites or lymph, the ratio for albumin-14C would be higher than that for albumin-"31I in lymph or ascites.The ratios of both labeled albumins found in ascites or lymph are expressed as per cent of the total plasma pool. In the eight patients studied 4.2-11.7% of the albumin-14C in plasma was found in ascites in 2 hr whereas only 0.4-2.2% of plasma albumin-WI entered in this same period. In the two patients studied during thoracic duct lymph drainage 6.1 and 13.5% of newly made albumin-14C appeared in lymph in 2 hr whereas only 2.8 and 3.8% of plasma albumin-"1I was found in the lymph.In cirrhosis with ascites some newly formed albumin entered ascites and thoracic duct lymph by a direct pathway from the liver bypassing the systemic circulation.

Filtration as the main mechanism of increased protein extravasation in liver cirrhosis

“…2 (appendix l), the return of tracer through a large extravascular volume will diminish the bending of the semilogarithmic plot of the intravascular tracer time-activity curves. Lymph derived from the liver is either returned to the circulation through the lymphatics or enters the peritoneal cavity directly [29]. present study, it seems likely, that only a smaller part of the increased splanchnic protein escape enters the peritoneal cavity directly.…”

The synthesis and secretion of albumin

“…This led to the suggestion of a direct pathway from the liver to the peritoneal cavity which bypasses the systemic circulation (Zimmon et al, 1969).…”

ALBUMIN SYNTHESIS††Supported in part by the U.S. Public Health Service Grants AA 00959 and HL 09562.

“…(7677) Essentially, complete distribution between intraplasma and extraplasma albumin pools takes place within a week to 10 days. (77) VIII. (73 -78) Approximately 75% of the plasma pool will exchange with the extravascular pool within 2 days, but some of the extravascular albumin exchanges more slowly, remaining in an extravascular site for many days.…”

“…These studies suggest an equivalent end response of the hepatic synthesizing mechanism for albumin to both the stress of fasting and acute exposure to alcohol, namely a destruction of the endoplasmic membrane-bound polysome. (77) Albumin must leak either from hepatic lymphatics or across the capsule of the liver. Excess quantities of stimulating amino acids possibly through the polyamine mechanism may be responsible for reversal in part of these acute effects.…”