USE OF THE HYPOXIA-INDUCED POLYCYTHEMIC MOUSE IN THE ASSAY AND STANDARDIZATION OF ERYTHROPOIETIN.

Abstract

Abstract The polycythemic mouse, produced by the method of discontinuous hypoxia, has been shown to be a highly sensitise test animal for the assay of erythropoietin. Exposure of such. mice to 0.4 atmosphere is more efficient for the production of suitable plethoric animals than 0.5 atmosphere; lower baselines of red blood cell Fe 59 incorporation are attained more rapidly after interruption of the lower pressure. With this assay method, Erythropoictin Standard B (ESA) was evaluated as a primary reference standard for the expression of unknown potencies by the use of the 4 point parallel-line procedure. Periodic calibration of a purified sheep-crythropoietin laboratory standard with ESA showed good reproducibility in slope, and precision characteristics, and potency ratios close to 1. Incubation of sheep erythropoietin in dog plasma for up to 5 hours did not affect the potency estimate, indicating the stability of the factor in this medium for at least that length of time. The dose/response relation of a number of human crythropoietin preparations was also studied. Several crude urine and plasma samples from patients with Cooley's anemia were found to be, amenable to 4 point analysis with the sheep standard.