scholarly journals Proteomic Sequencing of Stellate Ganglions in Rabbits With Myocardial Infarction

2021 ◽  
Vol 12 ◽  
Author(s):  
Lijun Cheng ◽  
Xinghua Wang ◽  
Hongda Chou ◽  
Tong Liu ◽  
Huaying Fu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stellate Ganglion ◽  
Control Group ◽  
Coronary Artery Ligation ◽  
Biological Processes ◽  
Artery Ligation ◽  
Cardiac Sympathetic Nerve Activity ◽  
Western Blot Experiment ◽  
Solid Foundation

The stellate ganglion (SG) of the autonomic nervous system plays important role in cardiovascular diseases (CDs). Myocardial infarction (MI) is associated with sustained increasing cardiac sympathetic nerve activity. Expressions and functions of proteins in SG tissue after MI are remaining unclear. This study is to explore the expression characteristics of proteins in SGs associated with MI. Japanese big-ear white rabbits (n = 22) were randomly assigned to the control group and MI group. The MI model was established by left anterior descending coronary artery ligation and confirmed by serum myocardial enzymes increasing 2,3,5-triphenyltetrazolium (TTC) staining and echocardiography. The expressions of proteins in rabbit SGs after MI were detected using tandem mass tags (TMT) quantitative proteomic sequencing. There were 3,043 credible proteins were predicted in rabbit SG tissues and 383 differentially expressed proteins (DEPs) including 143 upregulated and 240 downregulated proteins. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEPs involved in adrenergic signaling in cardiomyocytes, positive regulation of ERK1 and ERK2 cascade, and other biological processes. Three kinds of proteins directly correlated to CDs were selected to be validated by the subsequent western blot experiment. This study first identified the characterization of proteins in rabbit SG after MI, which laid a solid foundation for revealing the mechanism of roles of SG on the MI process.

Three-dimensional endocardial impedance mapping: a new approach for myocardial infarction assessment

2001 ◽  
Vol 280 (1) ◽  
pp. H179-H188 ◽  
Author(s):  
Tamir Wolf ◽  
Lior Gepstein ◽  
Gal Hayam ◽  
Asaph Zaretzky ◽  
Rona Shofty ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Three Dimensional ◽  
Interventional Cardiology ◽  
Mapping Technique ◽  
Control Group ◽  
Myocardial Tissue ◽  
Coronary Artery Ligation ◽  
Accurate Identification ◽  
Artery Ligation ◽  
Electromechanical Mapping

Precise identification of infarcted myocardial tissue is of importance in diagnostic and interventional cardiology. A three-dimensional, catheter-based endocardial electromechanical mapping technique was used to assess the ability of local endocardial impedance in delineating the exact location, size, and border of canine myocardial infarction. Electromechanical mapping of the left ventricle was performed in a control group ( n = 10) and 4 wk after left anterior descending coronary artery ligation ( n = 10). Impedance, bipolar electrogram amplitude, and endocardial local shortening (LS) were quantified. The infarcted area was compared with the corresponding regions in controls, revealing a significant reduction in impedance values [infarcted vs. controls: 168.8 ± 11.7 and 240.7 ± 22.3 Ω, respectively (means ± SE), P < 0.05] bipolar electrogram amplitude (1.8 ± 0.2 mV, 4.4 ± 0.7 mV, P < 0.05), and LS (−2.36 ± 1.6%, 11.9 ± 0.9%, P < 0.05). The accuracy of the impedance maps in delineating the location and extent of the infarcted region was demonstrated by the high correlation with the infarct area (Pearson's correlation coefficient = 0.942) and the accurate identification of the infarct borders in pathology. By accurately defining myocardial infarction and its borders, endocardial impedance mapping may become a clinically useful tool in differentiating healthy from necrotic myocardial tissue.

Abstract 250: Pericardial Grafting Of Cardiac Progenitor Cells In The Three-dimensional Thick Scaffold Improves Cardiac Function After Myocardial Infarction In Mice.

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Naomichi Kondo ◽  
Toshio Nagai ◽  
Mei-Lan Liu ◽  
Toshinao Takahashi ◽  
Masato Kanda ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Treatment Group ◽  
Cardiac Function ◽  
Three Dimensional ◽  
Control Group ◽  
Coronary Artery Ligation ◽  
Fish Analysis ◽  
Artery Ligation ◽  
Self Assembling ◽  
Graft Area

Cardiac progenitor cell (CPC) therapy for heart disease has been examined enthusiastically. However, optimal scaffolds which maintain the transplanted cells are still elusive. We used clonally expanded stem cell antigen 1-positive CPCs from adult mice and produced a three-dimensional thick scaffold (CPC-scaffold), in which CPCs were cultivated up to 2 month with self-assembling peptide RADA16-I. Addition of designer self-assembling peptide containing the active motifs of 2-unit RGD binding sequence and IGF-1 promoted three-dimensional spreading and viability of CPCs. After making myocardial infarction (MI) with left coronary artery ligation in mice, we transplanted CPC-scaffold on the surface of infarction area and confined it inside of the pericardial space by closing parietal pericardium. Four weeks after transplantation, echocardiography showed that FS of treatment group (16±10%, n=17) was higher than that of control (MI only) group (10±6.8%, n=19) (P<0.05) and that LVDd of treatment group (5.4±1.0mm, n=17) was smaller than that of control group (6.2±1.1mm, n=19) (P<0.05). Infarction area was significantly decreased in treatment group (46±21%, n=17), compared to control group (59±19%, n=18) (P<0.05). Immunohistochemical staining for von-Willebrand factor (vWF) showed that the number of vWF-positive capillaries per mm2 in treatment group (16.8±3.2, n=5) was higher than that of control group(8.9±3.4, n=5) (P<0.05). There were many of CD31-positive capillaries with or without α-smooth muscle cell actin-expressing perivascular cells in the graft area. By using fluorescent-conjugated avidin, biotin-labeled scaffold was globally detected in the graft area 1 week after transplantation, but sparsely 4weeks after, suggesting that the transplanted scaffold was biodegradable. To examine whether transplanted CPCs remain in the scaffold, we labeled CPCs with red fluorescence protein (RFP). RFP+CPCs were observed in the graft area 4 weeks after transplantation of RFP+CPC-scaffold. FISH analysis showed that sex-mismatched CPCs were globally detected in the graft area on the surface of the heart. Therefore pericardial grafting of well-vascularized and cellularized CPC-scaffold was a useful method to improve cardiac function after MI.

Abstract 177: Ticagrelor, but not Clopidogrel, Protects the Heart Against Reperfusion Injury and Improves Remodeling After Myocardial Infarction

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Yumei Ye ◽  
Jose R Perez-Polo ◽  
Manjyot K Nanhwan ◽  
Sven Nylander ◽  
Yochai Birnbaum
Keyword(s):  
Myocardial Infarction ◽  
Platelet Aggregation ◽  
Reperfusion Injury ◽  
Heart Function ◽  
Oral Treatment ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Control Group ◽  
Coronary Artery Ligation ◽  
Ventricular Ejection Fraction

Background: Clopidogrel (C) and Ticagrelor (T) are P2Y12 ADP receptor antagonists. In addition, ticagrelor inhibits adenosine cell uptake. In PLATO trial T reduced the incidence of the primary composite endpoint myocardial infarction, stroke or cardiovascular death over C in patients with acute coronary syndromes. Previous data show that 7d pretreatment with T limits infarct size (IS) in rats. We compared the effects of C and T, administered just before reperfusion on IS. We also assessed the effect of T and C, administered just before reperfusion and/or 6w oral treatment on cardiac remodeling. Methods: Rats underwent 30min coronary artery ligation. 1) At 25min of ischemia rats received intraperitoneal (IP) vehicle, T (10 or 30mg/kg), or C (12.5mg/kg). Area at risk (AR) was assessed by blue dye and IS by TTC staining 24h after reperfusion. 2) Rats received vehicle without (sham) or with (control) coronary ischemia, T (30mg/kg) IP (TIP), T (300mg/kg/d) oral for 6w, started a day after reperfusion (TPO), TIP+PO (TIPPO), or C (12.5mg/kg IP +62.5mg/kg/d PO for 6w). LV dimensions and function was assessed by echo at 6w. Results: 1) AR was comparable among groups. IS was 45.3±1.7% of the AR in the control group. T10 (31.5±1.8%; p=0.001) and T30 (21.4±2.6% p<0.001) significantly reduced IS, whereas C (42.4±2.6%) had no effect. Platelet aggregation in the controls was 64.7±1.3% and was comparable in T30 (24.9±1.8%) and C (23.2±1.8%) at 2h post reperfusion. T30 increased Akt, eNOS and ER1/2 phosphorylation 4h after reperfusion, whereas C had no effect. 2) Platelet aggregation at 1w oral treatment was 59.7±3.2% in the control group and was comparable in TIPPO (18.1±1.3%) and C (17.4±0.7%). Left ventricular ejection fraction was 77.6±0.9%*, 44.8±3.5%, 69.5±1.6%*, 69.2±1.0%*, 76.3±1.2%*, and 37.4±3.7% in the sham, vehicle, TIP, TPO, TIPPO and C treated group, respectively (*p<0.001 vs. vehicle). Left ventricular diameters at diastole and systole showed the same pattern. Conclusions: T, but not C, administered just before reperfusion protects against reperfusion injury. Oral T (in combination or not with acute treatment just before reperfusion) treatment for 6w improves heart function. C, despite achieving similar degree of platelet inhibition had no effect on remodeling.

Cardiac adaptations to endurance training in rats with a chronic myocardial infarction

1989 ◽  
Vol 66 (2) ◽  
pp. 712-719 ◽  
Author(s):  
T. I. Musch ◽  
R. L. Moore ◽  
P. G. Smaldone ◽  
M. Riedy ◽  
R. Zelis
Keyword(s):  
Myocardial Infarction ◽  
Endurance Training ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Coronary Artery Ligation ◽  
Maximal Heart Rate ◽  
Chronic Myocardial Infarction ◽  
Artery Ligation ◽  
Training Paradigm ◽  
Myosin Isozyme

The hemodynamic response to maximal exercise was determined in sedentary and trained rats with a chronic myocardial infarction (MI) produced by coronary artery ligation and in rats that underwent sham operations (SHAM). Infarct size in the MI groups of rats comprised 28–29% of the total left ventricle and resulted in both metabolic and hemodynamic changes that suggested that these animals had moderate compensated heart failure. The training regimen used in the present study produced significant increases in maximal O2 uptake (VO2max) when expressed in absolute terms (ml/min) or when normalized for body weight (ml.min-1.kg-1) and consisted of treadmill running at work loads that were equivalent to 70–80% of the animal's VO2max for a period of 60 min/day, 5 days/wk over an 8- to 10-wk interval. This training paradigm produced two major cardiocirculatory adaptations in the MI rat that had not been elicited previously when using a training paradigm of a lower intensity. First, the decrement in the maximal heart rate response to exercise (known as “chronotropic incompetence”) found in the sedentary MI rat was completely reversed by endurance training. Second, the downregulation of cardiac myosin isozyme composition from the fast ATPase V1 isoform toward the slower ATPase (V2 and V3) isoforms in the MI rat was partially reversed by endurance training. These cardiac adaptations occurred without a significant increase in left ventricular pump function as an increase in maximal cardiac output (Qmax) and maximal stroke volume (SVmax) did not occur in the trained MI rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Myocardial Infarction with Sequential Ligation of the Left Anterior Descending Artery and Its Diagonal Branch in Dogs and Sheep

2003 ◽  
Vol 26 (4) ◽  
pp. 351-357 ◽  
Author(s):  
W.G. Kim ◽  
Y.C. Shin ◽  
S.W. Hwang ◽  
C. Lee ◽  
C.Y. Na
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Pulmonary Artery ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Suitable Model ◽  
Artery Ligation ◽  
Diagonal Branch ◽  
Left Anterior Descending Artery ◽  
Arterial Blood

We report a comparison of the effects of myocardial infarction in dogs and sheep using sequential ligation of the left anterior descending artery (LAD) and its diagonal branch (DA), with hemodynamic, ultrasonographic and pathological evaluations. Five animals were used in each group. After surgical preparation, the LAD was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after one hour, the DA was ligated at the same level. Hemodynamic and ultrasonographic measurements were performed preligation, 30 minutes after LAD ligation, and 1 hour after DA ligation. As a control, two animals in each group were used for the simultaneous ligation of the LAD and the DA. Two months after the coronary ligation, the animals were evaluated as previously, and killed for postmortem examination of their hearts. All seven animals in the dog group survived the experimental procedures, while in the sheep group only animals with sequential ligation of the LAD and DA survived. Statistically significant decreases in systemic arterial blood pressure and cardiac output, and an increase in the pulmonary artery capillary wedge pressure (PACWP) were observed one hour after sequential ligation of the LAD and its DA in the sheep, while only systemic arterial pressures decreased in the dog. Ultrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all sheep, but in no dogs. Data two months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and PACWP in the sheep, but not in the dog. Left ventricular end-diastolic dimension and left ventricular end-systolic dimension in ultrasonographic studies were also increased only in the sheep. Pathologically, the well-demarcated thin-walled transmural anteroseptal infarcts with chamber enlargement were clearly seen in all specimens of sheep, and only-mild-to-moderate chamber enlargements with endocardial fibrosis were observed in the dog hearts. In conclusion, this study confirms that the dog is not a suitable model for myocardial infarction with failure by coronary artery ligation despite negligent operative mortality, when compared directly with an ovine model.

scholarly journals PO-173 The Effects of Interval Exercise on oxidative stress and Smyd1-related myocardial hypertrophy in Rats with Myocardial Infarction

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Qiaoqin Liang ◽  
Mengxin Cai ◽  
Jiaqi Zhang ◽  
Zhenjun Tian
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Cardiac Function ◽  
Stress Level ◽  
Exercise Group ◽  
Control Group ◽  
Coronary Artery Ligation ◽  
Interval Exercise ◽  
Oxidative Stress Level ◽  
Sarcomere Assembly

Objective This study was carried out to investigate interval exercise on Smyd1 expression and F-actin sarcomere assembly in non-infarcted myocardium of normal and myocardial infarction(MI) rats and its possible mechanism. Methods Male SD rats were randomly divided into normal control group (C), normal interval exercise group (CE), sham-operated group (S), MI group (MI), MI with interval exercise group (ME) and MI with ROS Tempol group (MT), n=10. MI model was established by left anterior descending coronary artery ligation. Interval exercise was carried out on a small animal treadmill. MT group was given an oral solution of Tempol (2mmol/L). Hemodynamics was performed to evaluate cardiac function. HE and Masson staining were used to analyze the cross-sectional area (CSA) of cardiomyocytes and collagen volume fraction, respectively. T-SOD and MDA kits were used to detect oxidative stress. H9C2 cells were treated with H2O2. Immunofluorescence staining was used to determine Smyd1 expression and F-actin sarcomere assembly. RT-qPCR and Western blotting were used to detect the gene or protein expression of Smyd1, Trx1, Hsp90, MuRF1, cTnI, α-actinin and BNP. Results Smyd1, Trx1, Hsp90, MuRF1 and BNP expression in the peri-infarcted area were up-regulated, but cTnI and α-actinin expression and F-actin assembly were decreased. The cardiac function was reduced. Both interval exercise and Tempol intervention significantly increase the CSA and expression of Smyd1, Trx1, cTnI and α-actinin, improve the antioxidation capacity and F-actin sarcomere assembly and cardiac function, reduce the expression of Hsp90, MuRF1, BNP and ROS level, and inhibit the fibrosis of myocardium. The oxidative stress level was closely related to the Smyd1 expression. Improvement of cardiac function were correlated with Smyd1 expression. H2O2 can induce oxidative stress injuries of H9C2, and its closely related to cardiomyocytes oxidative stress level and Smyd1 expression. Conclusions Interval exercise could promote antioxidant capability and physiological cardiomyocyte hypertrophy, regulate the expression of Smyd1, Hsp90 and MuRF1 in infarcted heart; so as to improve the cardiac function. Smyd1 may participate in pathologic hypertrophy of cardiomyocytes caused by oxidative stress.

Abstract 12648: Deletion of 12/15 Lipoxygenase Improves Left Ventricle Function and Survival by Resolving Inflammation Post Myocardial Infarction

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Vasundhara Kain ◽  
Kevin A Ingle ◽  
Janusz Kabarowski ◽  
Sumanth D Prabhu ◽  
Ganesh V Halade
Keyword(s):  
Myocardial Infarction ◽  
Left Ventricle ◽  
Survival Rates ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Lv Remodeling ◽  
Early Expression ◽  
Cox 2

12/15 lipoxygenase (LOX) is crucial in the inflammatory process leading to diabetes and atherosclerosis. However, the role of 12/15 LOX in myocardial infarction (MI) and left ventricle (LV) remodeling is unclear. We assessed the role of 12/15 LOX in resolving inflammation in post-MI LV remodeling. 8-12 weeks old C57BL/6J wild-type (WT; n=67) and 12/15 LOX (LOX –/– ; n=78) male mice were subjected to permanent coronary artery ligation surgery and monitored through day (d)1 and d5. No MI surgery mice were maintained as d0 naïve controls. LOX -/- mice showed higher survival rate, improved fractional shortening with reduced remodeling and edema index than WT at d1 and d5 post-MI (all p<0.05). LOX -/- mice showed increased Cxcl5 expression at d1 post-MI, consistent with stimulated neutrophil recruitment in the infarct region that was decreased at d5 compared to WT. LOX -/- mice infarct had increased expression of Ccl2 and Cxcl1, that stimulated an earlier recruitment of monocytes with increased macrophages population at d5 (all p<0.05) compared to WT. The altered kinetics of immune cells post-MI indicates a rapid resolving phase, through increase in alternative macrophage phenotypes with reduced collagen density in LOX -/- mice compared to WT mice at d5 post-MI. LOX -/- mice showed a coordinated COX-1 and COX-2 response at d1 post MI, leading to an evident increase in 5-LOX and hemoxygenase-1 (HO-1) at d5 post-MI. 12/15 LOX deletion enhanced the recruitment of alternative macrophages with secretion of HO-1 to resolve inflammation. In-vitro addition of LOX metabolite 12 hydroxyeicosatetraenoic acid to LOX -/- fibroblast induced early expression of COX-2 and 5-LOX compared to WT, indicating 5LOX role in resolution of inflammation. Post-MI increased expression of TIMP-1 and decrease in MMP-9 at d1 and α-SMA at d5 in LOX -/- mice suggested controlled differentiation of fibroblast-to-myofibroblast which is key event during ventricular tissue repair and resolving phase. This change is supported by increased expression of tgf-βi, ctgf and admats-2 (all P<0.05) at d5 post MI. In conclusion, absence of 12/15 LOX improves post-MI survival rates and attenuates LV dysfunction by resolving inflammation through coordination of 5-LOX and HO-1 as key inflammation resolving enzymes.

Abstract 2419: Left Ventricle Function Preservation by a Novel Synthetic Hydrogel Injection in Myocardial Infarction Rabbit

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Xiaoyan Li ◽  
Xuejun Jliang ◽  
Tao Wang ◽  
Taol Lin ◽  
Congxin Huang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Coronary Artery ◽  
Left Ventricle ◽  
Ethylene Glycol ◽  
Control Group ◽  
Coronary Artery Ligation ◽  
Poly Ethylene Glycol ◽  
Infarcted Myocardium ◽  
Poly Ethylene

Myocardial infarction and the subsequent heart failure remain among the world’s prominent health challenges. Other studies have demonstrated that bio-derived materials improve cardiac function after implantation for angiogenic potential. In this study, we hypothesized that injection of biomaterials into infarcted myocardium can preserve left ventricle (LV) function through its prevention of paradoxical systolic bulging. Infarction was induced in rabbit myocardium by coronary artery ligation. In sham-operated rabbits (n = 5), a suture was tied loosely around the left anterior descending coronary artery without ligating it. 7 dayslater, 100μl α-cyclodextrin (CD) solution and 100μl poly (ethylene glycol)-b-polycaprolactone-(dodecanedioic acid)-polycaprolactone-poly (ethylene glycol)(MPEG-PCL-MPEG) solution (n = 7) was injected simultaneously through Duploject applicator into the infarcted myocardium. Solid hydrogel matrix formed by linear MPEG-PCL-MPEG polymer threading into the cavities of the α-cyclodextrin after mixing. Injection of phosphate buffered saline (PBS) served as controls (n = 7). 28 days after the treatments, histological analysis indicated that injection of hydrogel prevented scar expansion and wall thinning compared with group ( P < 0.05) without more microvessel density in infarcted myocardium ( P = 0.70).By echocardiography, LV ejection fraction was significantly greater in the hydrogel group (56.09 ± 8.42%) than the control group (37.26 ± 6.36%, P = 0.001). The LV end-diastolic and end-systolic diameters were 2.07 ± 0.33 cm and 1.74 ± 0.30cm in the control group, respectively. Smaller LV end-diastolic diameter (1.61 ± 0.26cm, P = 0.005) and smaller end-systolic diameter (1.17 ± 0.23cm, P = 0.001) were found in the hydrogel group. These results suggest that α-CD/MPEG-PCL-MPEG hydrogel injection could serve structural and mechanical support of an injured LV replacing some of the functions of the damaged ECM and thus prevented paradoxical motion serves, which may eventually lead to LV remodeling and dilation prevention. Our study should initiate further experimental and clinical studies exploring potential approaches to the treatment of postinfarction heart failure.

Abstract 365: Targeted Delivery of IGF-1 Following Acute Myocardial Infarction

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Raffay S Khan ◽  
Jay C Sy ◽  
Milton Brown ◽  
Mario D Martinez ◽  
Niren Murthy ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Targeted Delivery ◽  
Coronary Artery Ligation ◽  
Nuclear Staining ◽  
Post Injection ◽  
Artery Ligation ◽  
Intact Cells ◽  
Double Stranded Dna

During acute myocardial infarction (MI) there is excessive necrosis of myocardial cells, leading to the release of large amounts of DNA, representing a potential target for drug delivery. Hoechst, a commonly used molecule for staining nuclei, binds to the minor groove of double-stranded DNA and can be functionalized to contain reactive groups such as free amines, sulfhydryls, and biotin moieties. Insulin-like growth factor-1 (IGF-1), a small molecule with a short half-life is protective immediately following MI, though there is potential for long-term toxicity and off-target effects. Therefore, we hypothesized that conjugating IGF-1 to Hoechst would increase targeting of IGF-1 to the injured myocardium. Hoechst-IGF1 (H-IGF1) was synthesized by binding Hoechst-biotin to biotinylated IGF-1 via a fluorescent streptavidin linker. Intact cells did not show nuclear staining with H-IGF1, while permeabilized cells had a significant increase in blue fluorescent Hoechst staining, indicating H-IGF1 was cell impermeable but could still bind DNA. Activity of H-IGF1 was demonstrated by Akt phosphorylation in cultured cardiac progenitor cells and was similar to native IGF-1. To determine in-vivo targeting of H-IGF1 to MI, mice underwent 30 minutes of coronary artery ligation followed by reperfusion (I/R). Six hours following MI, mice were injected intravenously with 70ng of H-IGF1, S-IGF1 (streptavidin bound IGF-1 only) or PBS followed by in vivo imaging at 30 and 120 minutes post-injection. At 30 minutes post-injection, we found 3.2% (2.2 of 70ng) of the injected dose of H-IGF1 in infarcted hearts compared with 1.8% (1.3 of 70ng) of S-IGF1 (n=5-7; p<0.05). To confirm that targeting of H-IGF1 was dependent on binding DNA, H-IGF1 pre-bound to double-stranded DNA was injected intravenously after I/R. This led to a significant (p<0.05) decrease in targeted IGF-1 levels. IGF-1 levels determined by ELISA 2 hours post-injection demonstrated a similar trend with increased targeting of H-IGF1 compared with S-IGF1 treated mice (4.2±0.6 ng vs. 2.4±0.2 ng; p<0.05). In conclusion, our data demonstrate that intravenous delivery of Hoechst-conjugated IGF-1 increases myocardial targeting. This provides a novel strategy for delivery of growth factors for the treatment of MI.

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