Influence of age and breed on the binding of oxygen to red blood
cells of bovine calves.
P., Gustin, Detry B., Robert A., Cao M. L., Lessire F., Cambier C.,
Katz V., Ansay M., Frans A. and Clerbaux Th.
Department of Pharmacology and Toxicology, Faculty of Veterinary
Medicine, ULg, B - 4000 Li_ge Belgium, Department of Internal
Medicine, Divisions of Pneumology and Cardiology, Cliniques
Universitaires Saint-Luc, UCL, B - 1200 Brussels Belgium, and
Department of Pharmacology and Toxicology, University of Veterinary
Medicine 1400 Budapest Hungary
APStracts 3:0541A, 1996.
The influence of somatic growth and genetic selection on the whole
blood oxygen equilibrium curve (OEC) was measured under standard
conditions in double-muscled and dairy calves during their first
three months of life. Cross-breed animals were also investigated.
Hemoglobin, 2,3-diphosphoglycerate (DPG),, chloride (Cl), and
inorganic phosphate (Pi) concentrations were also measured. The
percentage of fetal hemoglobin (HbF) was determined. The influence of
exogenous Cl, Pi, and pH on the OEC was also assessed. The PO2 at 50%
hemoglobin saturation (P50) increased during somatic growth, probably
due to the increase in DPG recorded in double muscled neonates and to
the progressive disappearance of HbF in both breeds. The oxygen
exchange fraction (OEF%) was used to assess the combined influence of
the OEC shift and OEC shape changes on blood oxygen desaturation
under standard conditions, when the PO2 decreases within a
physiological range.The OEF % showed an increase during the first
month, then a stabilization. The effects of Cl, Pi, and pH in
Friesian calves were similar as in and adult cattle. Double-muscled
neonates had a lower P50, OEF(%) values, and DPG concentrations, and
higher hemoglobin and Cl concentrations than Friesian neonates. The
Pi concentration and the percentage of HbF were similar in both
breeds. The pH and the Cl concentration had significantly less effect
on the OEC in double-muscled than in Friesian calves. Cross-breed
animals exhibited intermediate parameter values, between those
recorded for double-muscled and Friesian calves. All differences
between breeds progressively disappeared during the first month.
These data show that blood function changes markedly in calves during
the first month of life and that genetic selection can alter blood
function.
Received 10 January 1996; accepted in final form 11 November
1996.
APS Manuscript Number A26-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996