AJP - Endocrinology and Metabolism, Vol 238, Issue 3 245-E252, Copyright © 1980 by American Physiological Society
Evidence for a sexual variation in production of a hepatic erythropoietic factor by hepatectomized rats
B. A. Naughton, P. Liu, G. A. Kolks, J. M. Arce, S. J. Piliero and A. S. Gordon
Erythropoietin (Ep) is a glycoprotein hormone that is responsible for
mammalian red blood cell production. Adult rat liver regenerating 48-72 h
after hepatectomy (hepx) produces elevated levels of Ep in response to
hypoxia when compared to sham-operated, anephric hypoxic controls. A
factor, termed hepatopoietin (Hp), found in the serum of hepx rats, is
capable of stimulating hepatic Ep production when administered to normal
rats 18 h prior to hypoxic exposure. Although the hepatic vein is the most
potent source of this factor, Hp can also be demonstrated in the systemic
arterial circulation. Bilateral nephrectomy (nephrx) of the donor hepx
animal 24 h prior to bleeding abolishes this variation, and highest Ep
levels are noted when serum from a hepx and nephrx rat is administered to
animals immediatley after nephrx and 18 h before hypoxic exposure. Serum
derived from hepx male rats displays a greater ability to evoke hepatic Ep
production in normal recipients than serum from similarly treated female
rats. Regardless of the sex of the hepx donor, Ep elaboration after hypoxia
is highest in male recipients. The results indicate that there is a sexual
variation in the production of Hp as well as Ep.
