Résumé
Objective: To observe the protective effect of salidroside pretreatment on rabbit heart after limb ischemia/reperfusion (I/R). Methods: A total of 24 New Zealand rabbits were randomly and equally divided into sham operation group, I/R + placebo group （I/R group）and salidroside pretreatment group（salidroside group）. Before establishment of rabbit models of limb I/R, salidroside group received salidroside injection via ear marginal vein, and I/R group received saline injection, once a day for three days. After model establishment, echocardiography was used to evaluate rabbit cardiac function of each group 4h after reperfusion, including left ventricular end-systolic dimension (LVESd), left ventricular end-diastolic dimension (LVEDd), left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (FS). Blood sample was taken to measure serum cardiac troponin I (cTnI) and tumor necrosis factor (TNF)-α. Some ventricular tissue homogenates were taken to measure levels of superoxide dismutase (SOD) and malonyl diadehyde (MDA). Then heart sample was taken to receive pathological examination. Results: Compared with I/R group 4h after reperfusion, there were significant decrease in LVESd [(0.69±0.07) mm vs. (0.62±0.05) mm] and significant increase in LVEF [(64.6±3.4) % vs. (72.1±3.6) %], FS [(34.2±3.2) % vs. (41.7±3.4) %] (P0.05). Compared with I/R group, there were significant decrease in cTnI [(5.24±0.34) μg/ml vs. (1.06±0.12) μg/ml], MDA [(8.92±2.18) μmol/L vs. (6.79±1.43) μmol/L] and TNF-α [(37.43±10.02) pg/ L vs. (19.73±6.31) pg/ L], and significant increase in SOD level [(16.61±3.75) U/ml vs. (22.26±4.73) U/ml] in salidroside group (P<0.05 all). Pathological results indicated that injury degree in salidroside group was significantly attenuated than that of I/R group. Conclusion: Salidroside pretreatment could protect cardiac function and relieve rabbit cardiac injury after limb ischemia/reperfusion.
Résumé
Objective To explore the expression of recombinant adenovirus hypoxia-inducing factor-1? (HIF-1?) and its effects on the angiogenesis in a rat model of acute hindlimb ischemia. Methods (1) Recombinant adenovirus HIF-1?-Al?564 (Ad-H564 for short) was amplified in large scale in HEK293A cells and concentration gradient centrifuged in CsCl, purified by dialysis and then its titer was determined by spectrophotometry. (2) A model of acute ischemia in rats' hind limb was reproduced, and 72 rats were randomly allocated into Ad-LacZ group, Ad-H0 group, Ad-H564 group and control group (18 rats for each group). After the HIF-1? mRNA expression was detected, six rats of control group were intramuscularly injected with normal saline (NS group) to serve as control. Angiography and vascular cast were carried out in another two groups with in each six rats to serve as sham operated controls. In to hind limb skeletal muscles of rats of Ad-LacZ, Ad-H0 and Ad-H564 groups Ad-LacZ, Ad-H0 and Ad-H564 were respectively injected, normal saline was given to the rats of NS group, and nothing was given to the rats in sham group. (3) HIF-1? mRNA expression was determined by RT-PCR on the 1st, 3rd, 5th and 7th day after injection. (4) Selective arteriography and vascular cast were performed to evaluate the vascular density. Results (1) PCR and gene sequencing suggested that correct recombinant adenovirus HIF-1? was obtained after being amplified and purified, and the titer of adenovirus was 1011OPU/ml. (2) RT-PCR showed that the highest expression of HIF-1? mRNA (0.544 7?0.141 2) was seen in Ad-H564 group, and the value was significantly different compared with that of normal group and Ad-LacZ group (P=0.000), but it did not show significant difference compared with that of Ad-H564 group and Ad-H0 group (0.533 0?0.041 6, P=0.368). The expression of HIF-1? mRNA reached the highest value on the 7th day in all the groups. (3) Arteriography on the 28th day after injection showed that the density of the collateral vessels was higher in Ad-H564 group than that in Ad-H0 group, but no significant difference was found. Vascular casts showed denser microvasculature in Ad-H564 group than that in the other groups. Conclusions The present study suggests that single site mutation may enhance the expression of human HIF-1? gene in the local muscles, facilitate angiogenesis in the ischemic tissue, but no significant difference was found between the wild-type and the mutated HIF-1? genes.