Blood, 1955, Vol. 10, No. 7, pp. 735-752.
© 1955 American Society of Hematology, Inc.
The Effect of Various Metabolites on the Growth of
Marrow Cells in Vitro
HAROLD T. SWAN 1,
EDWARD H. REISNER JR. 1, and
MORRIS SILVERMAN 1
1 Division of Hematology, Department of Medicine, New York University Post-Graduate Medical School, New York City.
Marrow was cultured on chick plasma clots, glass surfaces and in suspension
and the influence of various metabolites and antimetabolites on the growth and
differentiation of red cell precursors was studied.
Vitamin B12 appeared to stimulate cell growth in cultures grown on clots and to
convert megaloblastic hematopoiesis to normoblastic in cultures grown on glass.
In suspension cultures of megaloblastic marrows in pernicious anemia serum
significant cell increases were obtained with the addition of folinic acid, but not
with vitamin B12. Both vitamin B12 and folinic acid appeared to accelerate the
conversion of megaloblasts to normoblasts in differential counts of stained
smears of such cultures. No enhancing effect of intrinsic factor upon the activity
of B12 in suspension cultures of megaloblasts was observed. The effect of folinic
acid could be blocked by colchicine and folinic acid could reverse the inhibitory
effects of Amethopterin. These facts indicated that folinic acid acted in suspension cultures by stimulating mitosis.
Megaloblasts could be produced from normoblastic marrows by culturing
them in pernicious anemia serum, or in normal serum in the presence of Amethopterin.
Submitted on November 23, 1954
Accepted on February 14, 1955
