ISSN:
1432-2013
Keywords:
Key words 12C79
;
HbA
;
KCC1
;
KCl cotransport
;
Oxygen
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Ouabain- and bumetanide-resistant K+ influx, and haemoglobin (Hb) O2 saturation, were measured in HbA red cells over a range of oxygen tensions (PO2 values) in the presence and absence of 12C79 (5 mM), a substituted benzaldehyde which increases the O2 affinity of Hb. PO2 values for half-maximal O2 saturation declined from 29±2 mmHg (mean ±SEM, n=3) in control cells to 7±1 mmHg with 12C79. In control cells, Cl–-dependent K+ influx (indicative of KCl cotransport activity) was fully O2 dependent, i.e. inactive at low PO2 values. By contrast, in the presence of 12C79, KCl cotransport was largely resistant to inactivation at low PO2 values. Substantial cotransport activity was still present (〉60% of that at high PO2 values) in N2, although O2 saturation was low (about 10%). In all cases, Cl–-independent K+ influxes were low [〈0.25 mmol (l cells h)–1] and unaffected by PO2 or 12C79. The significance of these results is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004240050807
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