Effect of phosphatidylcholine on lymphatic drainage and fluid loss from the peritoneal cavity of sheep.

The purpose of this investigation was to test the hypothesis that phosphatidylcholine enhances net ultrafiltration by decreasing lymphatic drainage of the peritoneal cavity. Twelve sheep were used in this study. Six animals received 50 ml/kg intraperitoneal infusions of Dianeal 4.25% (490 mOsm/liter) and six received similar volumes of premixed phosphatidylcholine-Dianeal (510 mOsm/liter). Labeled albumin (25 microCi 125I-human serum albumin) was added to the dialysate as a lymph flow marker. Lymph drainage of the peritoneal cavity was estimated from the appearance of the intraperitoneally administered tracer in the blood. Net ultrafiltration was significantly enhanced by phosphatidylcholine at each hour up to 6 hours post-infusion, and over this period reached 30.3 +/- 3.8 ml/kg in the phosphatidylcholine animals compared to 12.2 +/- 2.1 ml/kg in the control group. Phosphatidylcholine treatment decreased the volume removed by lymphatics; by six hours 5.5 +/- 1.1 ml/kg in the animals receiving phosphatidylcholine, and 10.3 +/- 1.0 ml/kg in the control group was drained as lymph. Fluid loss (estimated from the tracer disappearance from the peritoneal cavity) was slightly less in the phosphatidylcholine-treated animals, averaging 15.8 +/- 1.6 in this group versus 16.8 +/- 1.7 ml/kg in the control sheep. However, these differences were not significant. Phosphatidylcholine significantly increased transcapillary ultrafiltration (estimate of volume movement into peritoneal cavity without fluid loss) from 27.6 +/- 1.5 ml/kg in the controls to 43.8 +/- 3.4 ml/kg in the animals receiving phosphatidylcholine.(ABSTRACT TRUNCATED AT 250 WORDS)