LIGAND-EXCHANGE REACTION OF CARBONYLHEMOG LOBIN TO OXYHEMOGLOBIN IN AHEMOGLOBIN LIQUID MEMBRANE

In order to change carbonylhemoglobin (HbCO) to oxyhemoglobin(HbO(2)), the photodissociation of HbCO and O-2-binding to hemoglobin were stud ied using Hb liquid membrane system in O-2 atmosphere. The reduction r ate of HbCO increased with illuminance and saturated nearly at 2.0 . 1 0(5) 1x. under a constant O-2 pressure of 760 Torr. The reduction rate of HbCO was a 5-fold low when the partial O-2 pressure was decreased from 760 to 0 Torr under the illuminance. In the static liquid membran e the exchanging rate of CO ligand in HbCO was decreased with the incr ement of the thickness of the liquid membrane, while the stirred liqui d membrane showed a reverse result. The ligand exchange apparatus was made based on the obtained results, and the high flow rate of Hb solut ion enhanced the reduced amount of HbCO. Moreover, when the ligand exc hange of Hb-vesicle dispersion was compared with an Hb solution, it pr oceeded more efficiently due to the encapsulation of concentrated Hb i nto a small compartment dispersed in a buffer solution.