PT - JOURNAL ARTICLE AU - Marsh, M N TI - Studies of intestinal lymphoid tissue. II. Aspects of proliferation and migration of epithelial lymphocytes in the small intestine of mice. AID - 10.1136/gut.16.9.674 DP - 1975 Sep 01 TA - Gut PG - 674--682 VI - 16 IP - 9 4099 - http://gut.bmj.com/content/16/9/674.short 4100 - http://gut.bmj.com/content/16/9/674.full SO - Gut1975 Sep 01; 16 AB - Mice were given either intraperitoneal tritiated thymidine (3H-Tdr) or colchicine to study proliferation and migration of intestinal epithelial lymphocytes. Both labelled medium and large lymphocytes ('immunoblasts') were observed throughout the epithelium, crossing the basement membrane and within villous lymphatics for at least seven days after 3H-Tdr administration. Epithelial lymphocytes are predominantly young cells, actively dividing at the rate of 1% per hour. They do not migrate along the villi, unlike epithelial cells, but circulate rapidly through the epithelium, returning to the lamina propria at the rate of approximately 3 epithelial lymphocytes/1000 epithelial cell nuclei/hour. The labelling pattern of epithelial lymphocytes and intralymphatic cells with time was very similar suggesting that epithelial lymphocytes therefore may directly enter adjacent lymphatics and hence gain access to thoracic duct lymph.