Red blood cell catabolism in lymph nodes of the sheep and rat: quantitation

Estimates have been made of the number of red blood cells catabolised in the lymph nodes of the sheep and the rat. These estimates were based on observations on the output of bilirubin in intestinal lymph of the sheep and on bilirubin output in thoracic duct lymph of the rat. It was calculated that some 2 to 15 X 10(9) red blood cells were catabolised in a 24 hour period by the lymph nodes of the intestinal region of the sheep, representing approximately 3% of all the red cells destroyed in this period. Similarly, 0.9 to 4.6 X 10(8) red blood cells were estimated to be catabolised every 24 hours in the lymph nodes of those areas drained by the thoracic duct of the rat, representing approximately 6% of all the red cells destroyed in a 24 hour period. Calculations extending these results to include all areas of the body in both species indicated that the lymph nodes may account for some 6-7% of the total number of red blood cells catabolised in the animal.