THE ROLE OF THE LYMPHATIC SYSTEM IN THE ABSORPTION OF WATER FROM THE INTESTINE OF THE RAT

¹ Department of Physiology, The London Hospital Medical College, London, E.1.

The flow and composition of lymph in the cisterna chyli and mesenteric lymphatic vessel of the restrained conscious rat has been studied in relation to the ingestion of 5 ml. of water and isotonic saline. In both cases the lymph flow increases and the protein concentration of the lymph falls; the time relationships are, however, different. When water is taken, the response begins in a few minutes and is over in 30 minutes; when saline is taken, the response begins in 15 minutes and is over in 60 minutes. The excess amount of lymph recovered during the responses is about 0·8 ml. These studies, and studies with tritiated water, suggest that during the first 10 minutes after rats drink water there is a transient bulk flow of fluid from the intestinal lumen into the intestinal lymphatics. The intestinal lymphatics seem to act as an overflow system during the absorption of hypotonic fluid.

Note:

We are grateful to Miss Susan Young for skilled technical assistance. Miss D. Goodman estimated the sodium. We are indebted also to Professor J. L. Gowans, F.R.S., Professor C. J. O. R. Morris and Dr. J. Fawcett for advice and use of some apparatus. Professor K. W. Cross and Dr. P. Goodford kindly read the manuscript.