An analysis of the lymphocyte content of rat lacteals.

A technique for the collection of lymph from the lacteals of the small intestine of the rat is described. The output of lymphocytes from an area possessing a Peyer's patch is 10 times greater than in lymph from an area lacking one, but the proportion of lymphocytes with surface immunoglobulin (sIg), surface immunoglobulin A (sIgA), and internal immunoglobulin A (iIgA) are similar in the 2 areas. A lower percentage of lymphocytes bear sIg in lymph afferent to the mesenteric lymph gland compared with that found in the thoracic duct. However, a higher proportion of these lymphocytes bearing sIg have IgA on their surface in lacteal lymph compared with thoracic duct lymph. The reasons for these differences between the lacteal lymph and thoracic duct lymph are discussed.