44 The Lymphocyte and Lymphocytic Tissue 



strated histochemically in the lymphocytes by either the older Tween 

 methods 44 or the more recent azo dye procedures employing alpha-naphthyl 

 acetate, 23 ' " beta-naphthyl acetate, 72 napthol AS acetate, 23 napthol AS chlor- 

 oacetate, 45 and 5-bromo-indoxyl acetate as substrates. 77 Cytochemically only 

 minimal amounts of esterase activity has been ascribed to the lymphoid cells 

 in lymphatic tissue. 33, 34 However, using the indoxyl acetate substrate with 

 vital preparations, esterase activity can be seen in the cytoplasm of the lym- 

 phocytes (Fig. 3-26) as deposits of indigo blue crystals which tend to localize 

 near mitochondria." Larger lymphocytes may exhibit a somewhat greater 

 esterase activity with this method than the small lymphocytes in normal 

 blood. 7 Esterase activity has also been demonstrated in the cytoplasm of the 

 lymphoid cells from patients with chronic lymphocytic leukemia (Fig. 3-35), 

 lymphoblastic leukemia, and lymphosarcoma. 8 However, significant differ- 

 ences in the reactivity of these abnormal lymphocytes and normal lympho- 

 cytes was not observed with this technique. 8 By using a modified procedure 

 and napthol AS acetate as the substrate, esterase activity has been demon- 

 strated in the cytoplasm of lymphocytes in fixed films in both normal blood 

 and lymphocytic leukemia. 107 Lymphocytes fail to stain following methods 

 for the demonstration of cholinesterase. 35, 115 Nonspecific esterase activity 

 increases in the lymphatic tissue of the rat during the regeneration period 

 following x-radiation and decreases during the degenerative period.'"'' Im- 

 provement of histochemical methods for esterases may yield interesting 

 results. 



Phosphorylase. Phosphorylase activity could not be demonstrated in lym- 

 phocytes in normal blood films from a number of different species, includ- 

 ing man, 102 or in the lymphoid cells of lymphatic tissue. 101 - 102 However, the 

 great majority of lymphocytes in chronic lymphocytic leukemia and lympho- 

 sarcoma exhibit phosphorylase activity, while the lymphoblasts seen in one 

 case of acute lymphoblastic leukemia exhibited no phosphorylase activity. 70 

 A positive correlation was noted between phosphorylase activity and the 

 glycogen content in these cell forms, since glycogen was present in increased 

 amounts in lymphosarcoma and chronic lymphocytic leukemia and de- 

 creased in acute lymphoblastic leukemia. 70 



Beta-Glucuronidase. Beta-glucuronidase activity has been demonstrated 

 in the lymphoid follicles of the spleen 39 - 40 - 91 > 10 ° (Fig. 3-40) and tonsils but 

 could not be definitely localized to the lymphoid cells. 100 The cytoplasm of 

 the round cells of the follicles exhibits the highest enzyme activity, partic- 

 ularly the cells at the periphery of the follicles. 91 Considerable activity also 

 has been described in the round cells of the splenic pulp 40, 91 although germ- 

 inal centers are totally or partially unreactive. 39 Lymphocytes as well as other 

 leukocytes in blood and bone marrow films fail to exhibit beta-glucuroni- 



