Quantitative analysis of rod-cored vesicles and dense granules of large granular lymphocytes in the liver, spleen, and peripheral blood of rats.

Large granular lymphocytes (LGL) comprise a natural defense system in the liver and exert an inhibitory effect on tumor cell metastasis. In order to demonstrate the maturation of LGL in the liver from the morphological aspect, we evaluated electron-microscopically the frequency of 0.2 micron vesicles (rod-cored and "empty" vesicles) and dense granules in LGL from the liver, spleen, and peripheral blood of the rat. Both of these cell organelles are characteristic to LGL and may relate to natural killer-mediated cytolysis. On the average, there were 12.7 of the 0.2 micron vesicles and 4.3 rod-cored vesicles (RCV) per cell section in the liver, 6.6 0.2 micron vesicles and 1.6 RCV in the spleen, and 8.6 0.2 micron vesicles and 0.9 RCV in the peripheral blood. The number of 0.2 micron vesicles per cell section ranged from 0 to 19 with the exception of a few higher instances. Therefore, LGL were divided into vesicle-rich (> 9 0.2 micron vesicles per cell section) and vesicle-poor (< 8 per cell section) populations. Hepatic LGL consisted mainly of a vesicle-rich population while splenic LGL consisted mainly of a vesicle-poor population, and peripheral blood contained equal proportions of both populations. In addition to diversity with regard to the number of 0.2 micron vesicles, LGL obtained from various organs also displayed heterogeneity in the number and size of dense granules.(ABSTRACT TRUNCATED AT 250 WORDS)