Effect Of Physiological Concentration Of Melatonin On The Quality Of Erythrocyte Stored In Vitro

Objective To investigate whether physiological concentration of melatonin(MT)has a protective effect on the stored red blood cell(RBCs)in vitro.Methods Healthy adults were recruited,and 200 m L of whole blood was collected.After filtering white blood cells,plasma was removed by centrifugation,RBCs were resuspended in 50 m L MAP erythrocyte protective solution.The RBCs were gently mixed and then evenly distributed into 2 blood bags.MT was added to one bag(MT group)to reach the final concentration of 150pg/m L,and the other bag(control group)was added an equal volume of melatonin solvent.Then the bags were stored at 4 ?.At shelf life of 0 days,7 days,14 days,21 days,28 days,35 days and 42 days,5 m L blood sample was taken and to detect blood rutine,blood gas,blood flow changes,RBCs morphology,the content of glucose(Glu),lactate(Lac),Malondialdehyde(MDA),pH,the relative hemolysis rate of RBCs,red blood cell hemoglobin(Hb)re-release changes,the activity and content of RBCs major antioxidant enzyme,in order to observe whether MT has a protective effect on RBCs in vitro.Results Along with the increasing RBCs storage time,the quality of both group of RBCs is declining.However,the deformed RBCs,aggregation index,relative hemolysis rate,malondialdehyde(MDA)and methemoglobin fraction(FMet Hb)of MT group were significantly lower than those in control group,and the decreasing speed of pH was also lower than that of control group,and the difference was significant(P<0.05);the consumption of c Glu,ATP in MT group was lower than that in control group,at the same time c Lac also lower than the control group,but the difference was not significant(P>0.05);the decreasing rate of SOD,CAT and GSH-PX activity and the content of GSH in MT group was lower than that in control group,but the difference was not significant(P>0.05);Western blot(WB)results show during the RBCs stored process,Prx2 has been in a high state of expression,and the expression of Prx2 in MT group was higher than that in control group on day 42,the difference was significant(P<0.05).In addition,the re-released Hb from both control group and MT group was increased with storage time,however,compared with the control group,there was no significantdifference(P>0.05).Conclusion Physiological concentration of MT has the anti-oxidation function in vitro.It can protect morphology,prevent hemolysis,reduce aggregation and slow down the decrease rate of pH,while alsodelaying the degradationt of Prx2 that stored late erythrocytes and protect RBCs from oxidative damage caused by autoxidation of Hb.However,there was no significant effect on energy production,metabolism,antioxidant enzyme activity and Hb re-release.