Abstract: The oxygen affinity are one of important parameters of hemoglobin-based oxygen carriers(HBOCs), and are not completely understand at present. One theory considered that the low oxygen affinity are the main reason for the hypertension. In order to further research the relationship between the oxygen affinity and the hypertension, in this research, two Hemoglobin-based oxygen carriers(HBOCs) with low oxygen affinity were prepared. The raffinose were oxidized by sodium periodate (sodium periodate:raffinose=6:1, molar ratio), yielding a completely oxidized and homogeneous polyaldehyde ring-opened raffinose. It was used as the cross-linker to polymerize porcine deoxyhemoglobin, for 1 h to yield a low oxygen affinity (P50=43.1 torr) and mainly intro-molecular cross-linked 64 kDa hemoglobin(pCLHb); for 24 to yield a low oxygen affinity (P50=51.5 torr) and mean molecular weight 600 kDa polymerized hemoglobin(pPolyHb). With the two kind of HBOCs, 50% isovolemic exchange transfusion were performed in rat, the pCLHb caused an immediate and sustained hypertension but pPolyHb didn’t, and indicated hypertension are related to the 64 kDa hemoglobin and low oxygen affinity aren’t the main reason for hypertension.

Key words: Porcine hemoglobin, Raffinose, Hemoglobin-based oxygen carrier, Oxygen affinity, Hypertension