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

Abstract

The purpose of this study was to characterizethe cellular responses in the peritoneal cavityand draining lymph in a sterile peritonitismodel in conscious sheep. Lymph was collectedfrom lymphatics that drained the peritonealspace (caudal mediastinal and thoracic ducts)as well as from lymph vessels that drainedperipheral tissues (prescapular). Casein wasused as the inflammatory agent. Dialysissolution (Dianeal® 4.25%) containing 19%casein and 25 ]lCi 125f-human serum albuminwas infused into the peritoneal cavity in 50mllkg volumes. Peritoneal volumes increasedfrom a mean infused volume of 1572±51 ml toa maximum of 2119± 77 ml at 3 hours. Over 6hours, the number of macrophages andlymphocytes in the peritoneal cavity remainedrelatively constant but the number ofneutrophils increased from 9.9±4.2 x 107 to9.2±1.9 x 109 total cells. Caudal lymph whichdrains directly from the peritoneal cavitythrough diaphragmatic stomata, demonstrateda 5 fold increase in flow rate over 6 hoursfollowing the Dianeal-casein infusion.Thoracic duct and prescapular flows declinedapproximately 70% and 50% respectively in thesame time period. The concentration oflymphocytes and the lymphocyte outputs(product of volume and concentration) declinedin all lymph compartments. No elevations inneutrophil numbers in the thoracic andprescapular lymph compartments wereobserved but neutrophil output in the caudallymph increased steadily from 3.1±1.5 x 106 to4.6±1.3 x 10lJhr at the 6 hour mark. Weconclude that the major route of removal ofinflammatory cells and fluid from theperitoneal cavity is through diaphragmaticlymphatics.