Effect of bleeding on hematopoiesis following irradiation and marrow
transplantation
SS Boggs and DR Boggs
In previous studies, bleeding after irradiation did not affect the rate of
regeneration of endogenous spleen colony-forming cells, but induced an
early (4-6 days after irradiation) appearance of erythrocytic colonies
which differentiated and disappeared by days 7-8. This "abortive" wave was
associated with a similarly abortive wave of splenic 59Fe uptake. The
present experiments were done to determine whether or not an abortive wave
of erythropoiesis could be induced in the transplanted, exogenous stem cell
system. Lethally irradiated mice were given normal bone marrow cells and
one-half of the group were bled of about one-third their blood volume
within 4 hr of irradiation. Groups were killed on days 3-10 after
irradiation. Seventeen to twenty hours prior to killing, 59Fe was injected.
Hematocrits, spleen weights, colony numbers, and per cent 59Fe uptake were
determined. Hematocrits of bled mice averaged about 70% of those of
cell-injected controls. Spleen weights, colony counts, and per cent 59Fe
uptake per spleen began to increase about 1 day earlier in bled mice (days
4-5 as compared to days 5-6), and rates of increase were the same as those
of controls. However, no abortive wave of erythropoiesis was detected. A
large cell dose resulted in earlier increases in all parameters than a
small dose. Thus, bleeding after injection of cells produced results
similar to those obtained by increasing the cell dose. The inability of
bleeding to induce an early abortive wave of erythropoiesis in transplanted
as compared to endogenous colony-forming systems may reflect differences in
the cell cycling characteristics of these systems.
Volume 45,
Issue 2,
pp. 205-212,
02/01/1975
Copyright © 1975 by The American Society of Hematology
