Criteria of the Age of Lymphocytes in the Peripheral Blood

Abstract

The study of blood from rabbits with normal and with hyperactive lymphatic tissue reveals, in the latter, a greater percentage of lymphocytes with heavily basophilic cytoplasm and numerous mitochondria. This indicates that cytoplasmic basophilia and mitochondrial content can serve as criteria of the degree of maturity of the lymphocyte, these characters having the same significance in this relation as obtains with other blood cells. Basophilia is the more evident and reliable indicator of youth of the cells. The classification of lymphocytes into three groups, according to degree of basophilia, has yielded figures which show the proportions of the three to be relatively stable in blood from normal adult human beings and rabbits. Size is not strictly a function of age in lymphocytes. Moreover, there is no correspondence in the size of lymphocytes in supravital films and in fixed specimens obtained by the "cover glass" method. There is a change of size during fixation. Although lymphocytes of intermediate and large size may be of any age, in supravital preparations the majority are young cells, whereas in fixed films the reverse obtains. The small lymphocyte may be of any age in specimens examined by either technique. The total number of lymphocytes circulating at any given time is not necessarily an index to lymphoid activity.

Blood Lymphocytes in Supra-Vital and Dried Smear Preparations Studied With Mitochondrial Stain

“…Fig.2 shows the mean diam eter of lymphocytes belonging to different mitochondrial classes in supra-vital and dried smear pre parations. These data confirm the statem ent of Wiseman [1931] that large lymphocytes contain a larger number of mitochondria than small lymphocytes in supra-vital preparations. The spread and dried lymphocytes are generally smaller than the living lymphocytes.…”

Effect of 5‐fluorodeoxyuridine on Splenic Release of Lymphocytes

“…The present investigation has confirmed the occurrence of a release of splenic lymphocytes to the blood in guinea-pigs during the experimental circumstances described (see 1968, Sandberg 1970a). In the thymectomized animals this release was only slightly depressed.…”

“…1969). Lymphocytes with 0-15 mitochondria and with more than 15 mitochondria are denoted as small and large lymphocytes, respectively, as the mitochondria] content of the lymphocyte is correlated to the size of the lymphocyte ( Wiseman 1931, Fichtelius & Larsson 1961, Ernstrom & Larsson 1963.…”

Impairment of Phytohaemagglutinin-Induced Blastic Transformation in Lymphnodes from Thymectomized Mice

“…This is in apparent contrast to the much greater size of large pyroninophilic cells as measured in corresponding lymphnode sections. However, similar differences in lymphocyte size are well known to exist between supravital and fixed preparations of blood (83).…”