Tritiated-Thymidine Incorporating Cells in the Peripheral Blood of Normal and Splenectomized Rats.

The Number and Possible Functions of Dna‐synthesizing Cells in Human Blood

“…It was suggested that the labelled cells were derived directly or by metamorphosis from the antibody-forming cells in the spleen and that these cells might be important in the dissemination of immunological information (Cannon & Wissler, 1965). That the spleen is not the only source of DNA-synthesizing cells in rodent blood appears from the study of Chan et al (1967) which showed that splenectomy in rats is followed by a marked and sustained rise in [3H]thymidine-incorporating mononuclear cells in the blood, mainly monocytic cells, large, deeply basophilic blast-like cells, and small lymphocytes. It was hypothesized that splenectomy might stimulate lymphoid proliferation or lymphoid cell migration, or that the normal spleen might trap lymphoid cells or inhibit their release from lymphoid organs.…”

“…This non-specific mechanism could explain not only the increase in circulating DNA-synthesizing lymphoid cells after antigenic challenge but also the increase in other situations where the steady-state equilibrium of lymphoid-cell production may be disturbed, e.g. after splenectomy (Chan et al, 1967) and in the newborn (Winter et al, 1965). However, this possibility does not exclude that specific mechanisms may also be operating.…”

Blood Proliferocytes in Human and Animal Malaria

“…Blood proliferocytes during malaria may thus represent 'spillage' from the hyperplastic spleen during stimulation by work. Recently, however, Chan et al [10] reported that the number of 3H-thymidine labeled cells (proliferocytes) detected in normal rat blood increased as much as 4.5 fold 7 days after splenectomy. Increased blood proliferocytes persisted in their splenectomized rats for as long as 23 days; our results in mice and rats confirm and extend their findings.…”