Studies on Avian Erythrocyte Metabolism. XIII. Changing Organic Phosphate Composition in Age-Dependent Density Populations of Chicken Erythrocytes

Abstract

These studies were performed to determine whether the erythrocytes (RBC's) of chickens are able to alter the concentrations of organic phosphates, particularly inositol pentakis (dihydrogen phosphate) (inositol-P5), in response to anemia. Acute anemia with 33.5% reticulocytes (retics) in the peripheral blood of 4-month-old White Leghorn cockerels was produced after two successive days of controlled bleeding. Five populations of RBC's were prepared from blood of these anemic birds based upon age-dependent density by angle rotor centrifugation. The relative increase in age of Fraction 1 (younger cells) through Fraction 5 (oldest cells) was verified by increased hemoglobin concentration and decreased retic count and cell volume. The acid aqueous-soluble phosphates from each RBC fraction were extracted, fractionated by ion exchange column chromatography, and the concentration of inorganic phosphate (Pi), adenosine triphosphate (ATP), and inositol-P5 quantitated by wet-ash phosphate analysis. Determination of Pi, ATP, and inositol-P5 in Fraction 1 (younger cells, 7.4% retics) from the initial (Day 1) blood withdrawn gave 4.3, 5.7, and 18.6 mumoles Pi/ml RBC, respectively. On Day 4 of controlled-bleeding, Pi, ATP, and inositol-P5 concentrations in Fraction 1 (95.1% retics) were 12.7, 10.6, and 12.3 mumoles Pi/ml RBC, respectively. On Day 11, after 1 week recovery from controlled-bleeding, the values for Pi, ATP, and inositol-P5 in Fraction 1 (37.7% retics) were 5.0, 5.4, and 19.0 mumoles Pi/ml RBC, respectively, which were similar to the values before bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)