Transfusion of Plasma Collected at Late Phase after Preconditioning Reduces Myocardial Infarct Size Induced by Ischemia-reperfusion in Rats In vivo

Background： Plasma transfusion is a common clinical practice. Remote ischemic preconditioning （RIPC） protects organs against ischemia-reperfusion （IR） injury. Whether preconditioned plasma （PP）, collected at late phase after RIPC, could protect organs against IR injury in vivo is unknown. This study explored whether transfusion of PP could reduce myocardial inihrct size （IS） after I R in rat in vivo. Methods： Eighty Lewis rats were randomized to eight groups （n= 10 for each group）. Two groups of plasma donor rats donated plasma at 48 h after transient limb ischemia （PP） or control protocol （nonpreconditioned plasma [NPP]）. Six groups of recipient rats received normal saline （NS; NS-IR 1, and NS-1R 24 groups）, NPP （NPP-IR I and NPP-1R 24 groups）, or PP （PP-IR 1 and PP-IR 24 groups） at one or 24 h before myocardial IR. Myocardial IR consisted of 30-min left anterior descending （LAD） coronary artery occlusion and 180-rain reperIhsion. The area at risk （AAR） and infarct area were determined by double-staining with Evans blue and triphenyltetrazolium chloride. IS was calculated by inihrct area divided by AAR. This was a 3 × 2 factorial design study, and factorial analysis was used to evaluate the data. If an interaction between the fluid and transfusion time existed, one-way analysis of variance with Bonferroni correction lbr multiple comparisons was used to analyze the single effects of fluid type when the transfusion time was fixed. Results： IS in the NPP-IR I and PP-IR1 groups was smaller than in the NS-IR I group （F - 6.838, P = 0.005; NPP-IR I： 57 ± 8% vs. NS-IRI： 68± 6%, t = 2.843, P - 0.020; PP-IR I： 56 ~ 8% vs. NS-IR 1：68 ~ 6%, t - 3.102, P - 0.009）, but no significant difference was detected between the NPP-IR 1 and PP-IR 1 groups （57 ± 8% vs. 56 ± 8%, t 0.069, P = 1.000）. IS in the N PP-IR 24 and PP-IR 24 groups was smaller than in the NS-IR 24 group （F - 24.796, P 〈 0.001： NPP-IR 24： 56% ± 7% vs. NS-IR 24：68 ± 7%, t = 3.102, P =0.026; PP-IR 24：40±9% vs. NS-IR 24：68±7%, t = 7.237, P 〈 0.001 ）; IS in the PP-IR 24 group was smaller than in the NPP-IR 24 group （40 ＋ 9% vs. 56±7%, t = 4.135, P = 0.002）. Conclusion： Transfusion of PP collected at late phase after remote ischemic preconditioning could reduce IS, suggesting that late-phase cardioprotection was transferable in vivo.

Regular transient limb ischemia prevents atherosclerosis progression in hypercholesterolemic rabbits

Background:Endothelial dysfunction,the initial pathogenic factor in atherosclerosis,can be alleviated via transient limb ischemia.We observed the effects of regular transient limb ischemia (RTLI) on atherosclerosis in hypercholesterolemic rabbits.Methods:Twenty-eight rabbits were randomized to control,cholesterol,sham,ischemia groups (n=7 each) between October 2010 and March 2011.They were fed a normal diet in the control group and hypercholesterolemic diet in other groups for 12 weeks.Six cycles of RTLI were performed once per day on the ischemia group.Serum samples were prepared to measure the total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C) before the experiment (W0),at the end of weeks 4,8,12 (W4,W8,W12).The whole aorta was harvested at W12 and stained using Sudan IV to identify the plaque.The plaque area was measured using Image J.Results were analyzed by analysis of variance or rank sum test.Results:Concentrations of TC in the cholesterol group were higher than those in the control group at W4 (29.60 [23.75,39.30] vs.1.00 [0.80,1.55],Z =–2.745,P = 0.006),W8 (41.78 [28.08,47.37] vs.0.35 [0.10,0.68],Z =–2.739,P = 0.006),W12 (48.32 [40.04,48.95] vs.0.61 [0.50,0.86],Z =–2.739,P = 0.006).Similar results were obtained for HDL-C and LDL-C.Serum concentrations of TC,HDL-C,and LDL-C in the hypercholesterolemic groups had no differences (all P > 0.05).The percentage of plaque area in the cholesterol group was higher than that in the control group (47.22 ± 23.89% vs.0,Z =–2.986,P = 0.003).Square root of the percentage of plaque area was smaller in the ischemia group than that in the cholesterol (0.44 ± 0.13 vs.0.67 ± 0.18,P = 0.014) or sham groups (0.44 ± 0.13 vs.0.61 ± 0.12,P = 0.049).Conclusion:In hypercholesterolemic rabbits,RTLI might prevent atherosclerosis progression by reducing the percentage of plaque area.