2,3-Diphosphoglycerate Concentrations in Autologous Salvaged Versus Stored Red Blood Cells and in Surgical Patients After Transfusion.

BACKGROUND: Stored red blood cells (RBCs) are deficient in 2,3-diphosphoglycerate (2,3-DPG), but it is unclear how autologous salvaged blood (ASB) compares with stored blood and how rapidly 2,3-DPG levels return to normal after transfusion. Therefore, we compared levels of 2,3-DPG in stored versus ASB RBCs and in patients' blood after transfusion. METHODS: Twenty-four patients undergoing multilevel spine fusion surgery were enrolled. We measured 2,3-DPG and the oxyhemoglobin dissociation curve (P50) in samples taken from the ASB and stored blood bags before transfusion and in blood samples drawn from patients before and after transfusion. RESULTS: The mean storage duration for stored RBCs was 24 ± 8 days. Compared with fresh RBCs, stored RBCs had decreased 2,3-DPG levels (by approximately 90%; P < 0.0001) and a decreased P50 (by approximately 30%; P < 0.0001). However, ASB RBCs did not exhibit these changes. The mean 2,3-DPG concentration decreased by approximately 20% (P < 0.05) in postoperative blood sampled from patients who received 1 to 3 stored RBC units and by approximately 30% (P < 0.01) in those who received ≥4 stored RBC units. 2,3-DPG was unchanged in patients who received no stored blood or ASB alone. After surgery, 2,3-DPG levels recovered gradually over 3 postoperative days in patients who received stored RBCs. CONCLUSIONS: Stored RBCs, but not ASB RBCs, have decreased levels of 2,3-DPG and a left-shift in the oxyhemoglobin dissociation curve. Postoperatively, 2,3-DPG levels remain below preoperative baseline levels for up to 3 postoperative days in patients who receive stored RBCs but are unchanged in those who receive only ASB RBCs.

Assessment of antioxidant activity of eugenol in vitro and in vivo.

Reactive oxygen species are implicated in many human diseases and aging process. Much of the evidence is based on experimental data indicating increasing rates of lipid peroxidation in disease states and the ameliorating effects of antioxidants. It is becoming increasingly evident that the natural antioxidants, which have phenolic structure, play an important role in protecting the tissues against free radical damage. Eugenol (4-allyl-2 methoxyphenol) is one such naturally occurring phenolic compound. The antioxidant activity of eugenol was evaluated by the extent of protection offered against free radical-mediated lipid peroxidation using both in vitro and in vivo studies. The in vitro lipid peroxidation was induced in mitochondria by (Fe(II)-ascorbate) or (Fe(II) + H(2)O(2)). The lipid peroxidation was assessed colorimetrically by measuring the formation of thiobarbituric acid reactive substances (TBARS) following the reaction of oxidized lipids with TBA. Eugenol completely inhibited both iron and Fenton reagent-mediated lipid peroxidation. The inhibitory activity of eugenol was about fivefold higher than that observed for alpha-tocopherol and about tenfold less than that observed for BHT. The in vivo lipid peroxidation-mediated liver damage was induced by administration of CCl(4) to rats. Eugenol significantly inhibited the rise in SGOT activity and cell necrosis without protecting the endoplasmic reticulum (ER) damage as assessed by its failure to prevent a decrease in cytochrome p450 and G-6-phosphatase activity. The protective action of eugenol has been found to be due to interception of secondary radicals derived from ER lipids rather than interfering with primary radicals of CCl(4) (CCl(3)/CCl(3)OO).