Studies on the Mechanism of Erythropoietic Stimulation in Parabiotic Rats During Hypoxia

Abstract

Chronic hypoxemia was induced in one partner of a pair of parabiotic rats by exposure to defined gas mixtures with low oxygen content. The other partner of the pair was kept in normal atmosphere throughout the experiment and showed normal values of the oxygen saturation of the blood. The erythropoiesis, estimated by the percentage of nucleated red cells in the bone marrow, showed a statistically significant stimulation in both animals. It is, therefore, concluded that under these experimental conditions, the stimulus is not the partial pressure of oxygen in the bone marrow directly but a humoral factor elicited by the hypoxemia in the one partner and transferred to the other one.

Secondary polycythaemia associated with nocturnal apnoea — a relationship not mediated by erythropoietin?

“…On the other hand, hypoxaemia was shown to be a potent stimulus for the release of an erythropoiesis stimulating factor by cross-perfusion experiments in the early 1950s [7,81. and this factor has subsequently been shown to be constituted ofEPO [28, 291. The main sites of EPO synthesis are the kidney and liver r14, 15, 301.…”

Anaemia and Erythropoiesis in the Irradiated Rat: an Experimental Study with Particular Reference to Techniques involving Radioactive Iron

“…The explanation for the patterns of activity observed is clearly linked with the complex problem of normal haernopoietic regulation and the response following haemorrhage and anoxia (Erslev, 1953;Reissman, 1950). The nature and origin of endogenous erythropoietic stimulating factors are still obscure, but radioactive iron techniques offer a dynamic and quantitative method which can be useful in the understanding of these problems.…”

Diurnal Levels of Immunoreactive Erythropoietin in Normal Subjects and Subjects with Chronic Lung Disease

“…These patients, in contrast to normal subjects, exhibited a diurnal variation in the level ofimmunoreactive Ep with peak levels occurring at midnight. The only variable measured which correlated with the serum immunoreactive Ep level in subjects with chronic lung disease was the level of carboxyhaemoglobin (P< 0.02).The accepted stimulus for erythropoietin (Ep) production in both man and animals is tissue hypoxia (Reissmann, 1950;Erslev, 1953; Stohlman, 1962). Several physiologic adjustments are made when man is subjected to an hypoxic stress.…”

“…The accepted stimulus for erythropoietin (Ep) production in both man and animals is tissue hypoxia (Reissmann, 1950;Erslev, 1953; Stohlman, 1962). Several physiologic adjustments are made when man is subjected to an hypoxic stress.…”