AJP - Regulatory, Integrative and Comparative Physiology, Vol 246, Issue 2 236-R241, Copyright © 1984 by American Physiological Society
Erythrocyte phosphates and hemoglobin function in monotremes and some marsupials
R. Isaacks, S. Nicol, J. Sallis, R. Zeidler and H. D. Kim
Hematologic values, red blood cell (RBC) organic phosphate composition,
hemoglobin function, and hemoglobin composition have been determined on
blood from the monotremes, the duckbill platypus and the echidna, and three
species of marsupials, the Tasmanian devil, the wallaby, and the brush-tail
possum. Blood from the platypus had a RBC count of 8.63 X 10(6)/mm3, a mean
corpuscular volume of 49.1 millemicron3, and a white blood cell count of
26.0 X 10(3)/mm3. The RBCs from the monotremes and the three marsupials
exhibited hemoglobin polymorphism, each with three hemoglobin components.
Addition of ATP, 2,3-bisphosphoglycerate (2,3-P2-glycerate), or inositol
pentakisphosphate (inositol-P5) to phosphate-free hemoglobin from each
species decreased hemoglobin oxygen affinity; the order of effect of these
compounds was ATP less than 2,3-P2-glycerate less than inositol-P5. The
RBCs of all species had concentrations of 2,3-P2-glycerate ranging from
6.02 mumol/ml RBCs in the wallaby to 10.39 mumol/ml RBCs in the possum. The
RBCs from the three species of marsupials had concentrations of ATP ranging
from 0.24 mumol/ml RBCs in the possum to 0.80 mumol/ml RBCs in the
Tasmanian devil. The level of ATP in RBCs of the platypus and echidna were
0.06 and 0.03 mumol/ml RBCs, respectively.
