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

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-(131)I and carbonate-(14)C were injected intravenously. The albumin-(131)I measured the transfer of plasma albumin into ascites and into thoracic duct lymph. The carbonate-(14)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-(14)C and -(131)I in ascites and lymph compared with the content of albumin-(14)C and -(131)I in plasma would be identical. However, if some newly formed albumin is delivered directly into ascites or lymph, the ratio for albumin-(14)C would be higher than that for albumin-(131)I 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-(14)C in plasma was found in ascites in 2 hr whereas only 0.4-2.2% of plasma albumin-(131)I entered in this same period. In the two patients studied during thoracic duct lymph drainage 6.1 and 13.5% of newly made albumin-(14)C appeared in lymph in 2 hr whereas only 2.8 and 3.8% of plasma albumin-(131)I 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.