Cf. Cartheuser, STANDARD AND PH-AFFECTED HEMOGLOBIN-O(2) BINDING CURVES OF SPRAGUE-DAWLEY RATS UNDER NORMAL AND SHIFTED P-50 CONDITIONS, Comparative biochemistry and physiology. Part A, Physiology, 106(4), 1993, pp. 775-782
1. The oxygen saturation (SO2 was determined of Sprague-Dawley rat blo
od having increased hemoglobin (Hb)-O-2 affinity (P-50 <37 mmHg) or ca
pacity (C-max over a range of pH's. 2. Rats were untreated (K), or had
passed 14 d drinking 0.5% saline (C; ctrl) or NaOCN (N; chronically l
ow P-50 high C-max), 5000m altitude acclimatization (H; high C-max or
exchange transfusion with OCN--Hb red cell blood (X; acutely low P,(50
). 3. The P-50, [mmHg], Hill's ''n'', and C-max,[ml O-2/100 ml], measu
red after tonometry, were 36.0, 2.60 and 20.6 (K), 32.6, 2.50 and 21.8
(C), 18.3, 2.35 and 23.9 (N), 36.0, 2.60 and 29.4 (H), and 24.9, 2.73
and 22.3 (X). 4. Oxygen dissociation curves (ODC's), derived from sim
ultaneous SO2 and PO2 measurements during deoxygenation (PO2:100-0 mmH
g) of blood (normal and acidified with CO2 or lactic acid), delivered
Bohr coefficients (BCCO2, BCLac) each differing between groups (C vs N
) above SO2 50%; within groups BCCO2 vs BCLac differed at SO2 10-90% (
P < 0.05). 5. Group-specific ODC's and pH-shifted curves (+/-0.05, +/-
0.10 and +/-0.15 units from 7.4, relying on BCCO2) are plotted for dir
ect reading of SO2 and, with C-max accurate data on blood O-2 content
are obtained; corrections for lactic acidosis are discussed.