Blood, 1959, Vol. 14, No. 3, pp. 262-273.
© 1959 American Society of Hematology, Inc.
On the Erythropoietic Principle in the Blood of Rabbits
Made Severely Anemic with Phenylhydrazine
PETER H. LOWY 1,
GEOFFREY KEIGHLEY 1,
HENRY BORSOOK 1, and
ASHTON GRAYBIEL 1
1 Kerckhoff Laboratories of Biology, California Institute of Technology, Pasadena, Calif. and the U.S. Naval School of Aviation Medicine, Pensacola, Fla.
1. An assay for erythropoietic factor is described based on reticulocytosis
in normal, adult mice. The advantages of the method are the short time
required (4 days), the small amount of test material needed and the facility
with which many tests may be run simultaneously.
2. For the measurement of uptake of Fe59 a procedure is described which
allows counting of whole dried blood with an end-window Geiger-Müller tube.
3. A procedure is described for preparing highly active erythropoietic filtrates from the boiled plasma of rabbits made severely anemic with phenylhydrazine.
4. Evidence is presented that the ineffectiveness of whole plasma (anemic)
on the one hand, and the effectiveness of the filtrate after the plasma is boiled
on the other hand, is associated with respective presence and absence of
antibody-provoking antigens.
5. A fractionation procedure is described whereby a fraction was obtained
which, on the basis of amount of protein, is much more potent than unfractionated plasma filtrate, by tests based on reticulocytosis in mice, uptake
of Fe59 in starved rats and polycythemia in normal rats. When this material
was subjected to zone electrophoresis two-thirds of its protein and all the
activity was found confined to one band. It is noteworthy that the material
which gave the positive responses to the three tests has so far remained
together in one fraction.
6. Some physical and chemical properties of erythropoietically active plasma
fractions are described. So far erythropoietic activity has been inseparable
from protein.
7. A number of hormones, vitamins and other growth-promoting materials
were tested for erythropoietic activity and were found to be negative by the
tests employed.
Submitted on May 2, 1958
Accepted on June 29, 1958
