Protoporphyrin and heme formation by erythrocytes from the x-irradiated and bled duck

¹ Biology Department, Brookhaven National Laboratory, Upton, New York

Frequent bleeding of the adult, male duck was followed by increase in protoheme and free protoporphyrin formation by erythrocytes in vitro. X-irradiation of the animal with 800 or 1,200 r was followed by decrease in heme formation but not in free porphyrin production. Heme formation was not limited by the natural supply of porphyrin precursors and iron in blood and appears to be controlled by the uptake of iron by the cells. Free porphyrin production does not appear to be regulated by heme formation.