LYMPH-FLOW AND LYMPHATIC DRAINAGE OF INFLAMMATORY CELLS FROM THE PERITONEAL-CAVITY IN A CASEIN-PERITONITIS MODEL IN SHEEP

The purpose of this study was to characterize the cellular responses i n the peritoneal cavity and draining lymph in a sterile peritonitis mo del in conscious sheep. Lymph was collected from lymphatics that drain ed the peritoneal space (caudal mediastinal and thoracic ducts) as wel l as from lymph vessels that drained peripheral tissues (prescapular). Casein was used as the inflammatory agent. Dialysis solution (Dianeal (R) 4.25%) containing 1g% casein and 25 mu Ci I-125-human serum albumi n was infused into the peritoneal cavity in 50 ml/kg volumes. Peritone al volumes increased from a mean infused volume of 1572 +/- 51 ml to a maximum of 2119 +/- 77 ml at 3 hours. Over 6 hours, the number of mac rophages and lymphocytes in the peritoneal cavity remained relatively constant but the number of neutrophils increased from 9.9 +/- 4.2 x 10 (7) to 9.2 +/- 1.9 x 10(9) total cells. Caudal lymph which drains dire ctly from the peritoneal cavity through diaphragmatic stomata, demonst rated a 5-fold increase in flow rate over 6 hours following the Dianea l-casein infusion. Thoracic duct and prescapular flows declined approx imately 70% and 50% respectively in the same time period. The concentr ation of lymphocytes and the lymphocyte outputs (product of volume and concentration) declined in all lymph compartments. No elevations in n eutrophil numbers in the thoracic and prescapular lymph compartments w ere observed but neutrophil output in the caudal lymph increased stead ily from 3.1 +/- 1.5 x 10(6) to 4.6 +/- 1.3 x 10(7) /hr at the 6 hour mark. We conclude that the major route of removal of inflammatory cell s and fluid from the peritoneal cavity is through diaphragmatic lympha tics.