Oxygen-linked binding of halothane to human adult haemoglobin
Guesnon, P.; Bohn, B.; Bursaux, E.; Poyart, C.
British Journal of Anaesthesia 52(12): 1177-1181
1980
ISSN/ISBN: 0007-0912 PMID: 7448097 Document Number: 168300
The affinity for O2 of normal adult human Hb solutions was measured in the presence of increasing concentrations of halothane. A maximum increase in P50 [partial pressure of O2 at half saturation of Hb] of 25% with halothane 40 kPa compared with control (O2-Ar gas mixtures) indicating the O2-linked character of the binding of halothane to the Hb molecule was observed. The effect of halothane on P50 was independent of pH between 7.0 and 8.0 and of Cl- concentration between 10-100 mmol/l. This suggests that halothane-Hb interactions may occur through hydrophobic linkage as occurs with short chain aliphatic hydrocarbons. The O2-linked binding of halothane appears of minor importance in altering O2 binding to Hb in vivo compared with other factors such as Cl- ion or 2,3-DPG [2, 3-diphosphoglycerate].