Oxidative stress in dogs with anemia and effects of vitamin E + selenium application to donors on quality of stored whole blood

The aims of the present study were to evaluate the oxidative stress in dogs with anemia by taking into account the severity and type of anemia and to determine the effects of vitamin E + selenium application to donor dogs on the quality of stored whole blood in bags containing CPDA-1. Fifty dogs with anemia and 14 out of 20 healthy dogs presenting donor features with a total of 70 dogs of various breeds, ages and of both sexes were enrolled into the study. Fifty dogs with anemia were classified as mildly (n=18), moderately (n=18) and severely (n=14) anemic by HCT value, regenerative (n=26) and nonregenerative (n=24) also by absolute reticulocyte count. Twenty dogs were kept as control. Fourteen dogs with donor property were divided into two equal groups (n=7) as antioxidant and control. Dogs in the antioxidant group received 150 mg of vitamin E + 0.5 mg selenium/20 kg BW subcutaneously for two portions with fourteen days interval (-15th and -1st days) while the donors in control group were administered an equal volume of 0.9% NaCl on the same days. Measurements were performed on samples collected at days 0, 1, 3, 7, 14, 21, 28 and 35 from whole blood collected into CPDA-1 bags and stored at +4 °C one day after the second application. Hematological evaluations included WBC, RBC, HGB, HCT, MCV, MCH, MCHC and PLT measurements. TOS, TAC and MDA values in plasma and erythrocyte SOD, GSH-Px, CAT activities were measured in respect to evaluate the oxidant-antioxidant status. Analysis were carried out once in anemic dogs and healthy group while from the dogs in the antioxidant and control groups were carried out twice, before and after the second vitamin E + selenium or 0.9% NaCl application. Hematological parameters and oxidant-antioxidant status biomarkers were measured on stored whole blood at the above-mentioned 8 sampling times. There were no statistically significant relations between severity (HCT) and type (number of reticulocytes) of anemia and oxidant (TOS, MDA) and antioxidant (TAC, SOD, GSH-Px, CAT) biomarkers in 50 dogs with anemia. Plasma mean or median TOS and TAC values and MDA concentration were significantly higher, and erythrocyte GSH-Px activity was significantly lower in 50 anemic dogs when compared with healthy group. Plasma TOS value was increased in all groups according to the severity of anemia, while a significant increase in TAC value and a significant decrease in erythrocyte GSH-Px activity in mild and moderate anemia. Plasma TOS and TAC values were higher in both types of anemic (regenerative and nonregenerative) dogs when compared with healthy group, a significant increase in plasma MDA concentration and a significant decrease in GSH-Px activity were observed in nonregenerative group. WBC, RBC, HCT, HGB and MDA levels decreased (p <0.05) significantly while level of plasma HGB concentration (p <0.05) and erythrocyte SOD activity (p <0.01) increased in the donor dogs administered vitamin E + selenium applied two times with fourteen days interval. The decreases in RBC, HGB, HCT, PLT and K+ values and increase in plasma TAC value of both group were determined significant in the first 2-4 hours of storage time after collecting blood to bags containing CPDA-1. Decrease in WBC count and increase in GSH-Px activity of antioxidant group and increase in MCV value and decrease in MCHC value of control group were statistically significant. Repeated measures analysis of variance showed significant alterations in WBC, HCT, MCV, MCH and MCHC values over time but differences between groups and time by group interaction were not significant in storage of whole blood at +4 ° C for 35 days. Plasma K+ and HGB concentrations and LDH activity increased significantly over time but differences between groups and time by group interaction were not significant except LDH. Plasma TAC concentration and erythrocyte SOD, GSH-Px activities decreased while plasma TOS and MDA levels increased significantly over time. There was a significant effect of group and time by group interaction as increase in TOS value and decrease in SOD activities. In conclusion, oxidative stress develops in dogs with anemia and it is largely independent from the severity and type of anemia. Secondly subcutaneous vitamin E + selenium administration to the donor dogs prior to blood collection two times with fourteen days interval improves the quality of stored blood by reducing some harmful effects of free radicals. Based on these results, it was suggested that further studies may be useful for evaluating the efficacy of antioxidant application with different doses and combinations as part of treatment in anemic dogs and prior to blood collection to donor dogs.