scholarly journals DRD4 Mitigates Myocardial Ischemia/Reperfusion Injury in Association With PI3K/AKT Mediated Glucose Metabolism

2021 ◽  
Vol 11 ◽  
Author(s):  
Xue-song Liu ◽  
Jing Zeng ◽  
Yu-xue Yang ◽  
Chun-lei Qi ◽  
Ting Xiong ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Western Blot ◽  
Troponin T ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Flow Cytometer ◽  
Akt Pathway ◽  
Tunel Staining

Ischemia-reperfusion (I/R) could cause heart irreversible damage, which is tightly combined with glucose metabolism disorder. It is demonstrated that GLUT4 (glucose transporter 4) translocation is critical for glucose metabolism in the cardiomyocytes under I/R injury. Moreover, DRD4 (dopamine receptor D4) modulate glucose metabolism, and protect neurocytes from anoxia/reoxygenation (A/R) injury. Thus, DRD4 might regulate myocardial I/R injury in association with GLUT4-mediated glucose metabolism. However, the effects and mechanisms are largely unknown. In the present study, the effect of DRD4 in heart I/R injury were studied ex vivo and in vitro. For I/R injury ex vivo, DRD4 agonist (PD168077) was perfused by Langendorff system in the isolated rat heart. DRD4 activated by PD168077 improved cardiac function in the I/R-injured heart as determined by the left ventricular developed pressure (LVDP), +dp/dt, and left ventricular end diastolic pressure (LVEDP), and reduced heart damage evidenced by infarct size, the release of troponin T (TNT) and lactate dehydrogenase (LDH). DRD4 activation diminished I/R injury induced apoptosis and enhanced cell viability impaired by I/R injury in cardiomyocyte, showed by TUNEL staining, flow cytometer and CCK8 assay. Furthermore, DRD4 activation did not change total GULT4 protein expression level but increased the membrane GULT4 localization determined by western blot. In terms of mechanism, DRD4 activation increased pPI3K/p-AKT but not the total PI3K/AKT during anoxia/reoxygenation (A/R) injury in vitro. Interestingly, PI3K inhibitor, Wortmannin, blocked PI3K/AKT pathway and depleted the membrane GULT4, and further promoted apoptosis showed by TUNEL staining, flow cytometer, western blot of cleaved caspase 3, BAX and BCL2 expression. Thus, DRD4 activation exerted a protective effect against I/R injury by promoting GLUT4 translocation depended on PI3K/AKT pathway, which enhanced the ability of glucose uptake, and ultimately reduced the apoptosis in cardiomyocytes.

The Protective of Baicalin on Myocardial Ischemia-Reperfusion Injury

2020 ◽  
Vol 21 (13) ◽  
pp. 1386-1393
Author(s):  
Xiaoli Liu ◽  
Shanshan Zhang ◽  
Chaoyue Xu ◽  
Yongchao Sun ◽  
Shujian Sui ◽  
...  
Keyword(s):  
Survival Rate ◽  
Protein Expression ◽  
Western Blot ◽  
Ischemia Reperfusion ◽  
Specific Inhibitor ◽  
Maximum Velocity ◽  
Left Ventricular ◽  
Tunel Staining ◽  
Acetoxymethyl Ester ◽  
Myocardial Apoptosis

Background: The aim of this study was to explore the inhibitory effect of baicalin on myocardial apoptosis induced by Ischemia-Reperfusion (I/R). Methods: Sprague Dawley rats' heart and myocardial cells I/R model were established in vivo and vitro, then 100 mg/kg and 10 μmol/l baicalin were administrated, respectively. The experiment was randomly divided into 4 groups (n=10): Control; I/R; IR+DMEM; and I/R+baicalin groups. Postoperation, the Left Ventricular (LV) End-Diastolic Pressure (LVEDP), the maximum velocity of LV contraction (dP/dtmax) and the maximum velocity of LV diastole (dP/dtmin) were recorded by the transthoracic echocardiography; the myocardial apoptosis percentage was analyzed by Annexin VFITC/ PI and TUNEL staining, and the apoptosis gene and protein were detected by RT-PCR and western blot. Furthermore, the protein expression of the calcium-sensing receptor (CaSR) and ERK1/2 phosphorylation were observed by western blot and Fura-2-acetoxymethyl ester. Moreover, primary rats’ cardiomyocytes were cultured and ERK1/2 specific inhibitor PD98059 was added to the culture medium. The cell survival rate, vitality and apoptosis were detected by MTT, lactate dehydrogenase (LDH) and TUNEL staining assay Kit, respectively. Results: Our present study showed that baicalin significantly improved LV hemodynamic parameters and myocardial apoptosis in myocardial I/R injury rats. Furthermore, we found that baicalin could down-regulate the protein expression of CaSR, but up-regulate the protein expression of ERK1/2. Furthermore, when the cells were pretreated with ERK1/2 inhibitor PD98059, the cells survival rate significantly decreased, but LDH activity and apoptosis significantly increased. The results indicated that the effect of baicalin on myocardial I/R injury could be inhibited by ERK1/2 inhibitor. Conclusion: In conclusion, our data suggests that baicalin attenuates I/R-induced myocardial injury maybe through the suppression of the CaSR/ERK1/2 signaling pathway.

scholarly journals p21-activated kinase improves cardiac contractility during ischemia-reperfusion concomitant with changes in troponin-T and myosin light chain 2 phosphorylation

2012 ◽  
Vol 302 (1) ◽  
pp. H224-H230 ◽  
Author(s):  
Michelle M. Monasky ◽  
Domenico M. Taglieri ◽  
Bindiya G. Patel ◽  
Jonathan Chernoff ◽  
Beata M. Wolska ◽  
...  
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Diastolic Pressure ◽  
Troponin T ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Cardiac Contractility ◽  
Left Ventricular ◽  
Myosin Light Chain 2 ◽  
P21 Activated Kinase

p21-activated kinase 1 (Pak1) is a serine/threonine kinase that activates protein phosphatase 2a, resulting in the dephosphorylation of cardiac proteins and increased myofilament Ca2+ sensitivity. Emerging evidence indirectly indicates a role for Pak1 in ischemia-reperfusion (I/R), but direct evidence is lacking. We hypothesize that activation of the Pak1 signaling pathway is a cardioprotective mechanism that prevents or reverses the detrimental effects of ischemic injury by inducing posttranslational modifications in myofilament proteins that ultimately improve cardiac contractility following ischemic insult. In the present study, we subjected ex vivo hearts from wild-type (WT) and Pak1-knockout (KO) mice to 20 min of global cardiac ischemia followed by 30 min of reperfusion. In the absence of Pak1, there was an exacerbation of the increased end-diastolic pressure and reduced left ventricular developed pressure occurring after I/R injury. ProQ analysis revealed an increase in troponin-T phosphorylation at baseline in Pak1-KO hearts compared with WT. Significantly decreased myosin light chain 2 (MLC2) phosphorylation in Pak1-KO hearts compared with WT after I/R injury was confirmed by Western immunoblotting. These data indicate that Pak1-KO hearts have reduced recovery of myocardial performance after global I/R injury concomitant with changes in troponin-T and MLC2 phosphorylation. Finally, a protein-protein association between Pak1 and MLC2, and Pak1 and troponin-T, was determined by coimmunoprecipitation. Thus, results of our study provide a basis for targeting a novel pathway, including Pak1, in the therapies for patients with ischemic events.

The Anti-tumor Activity and Mechanisms of rLj-RGD3 on Human Laryngeal Squamous Carcinoma Hep2 Cells

2020 ◽  
Vol 19 (17) ◽  
pp. 2108-2119
Author(s):  
Yang Jin ◽  
Li Lv ◽  
Shu-Xiang Ning ◽  
Ji-Hong Wang ◽  
Rong Xiao
Keyword(s):  
Wound Healing ◽  
Western Blot ◽  
Morphological Changes ◽  
In Vivo Studies ◽  
Migration And Invasion ◽  
Tunel Staining ◽  
Dna Ladder ◽  
Western Blot Assay

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: hese results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.

scholarly journals Cardioprotective Effects of PPARβ/δ Activation against Ischemia/Reperfusion Injury in Rat Heart Are Associated with ALDH2 Upregulation, Amelioration of Oxidative Stress and Preservation of Mitochondrial Energy Production

2021 ◽  
Vol 22 (12) ◽  
pp. 6399
Author(s):  
Ioanna Papatheodorou ◽  
Eleftheria Galatou ◽  
Georgios-Dimitrios Panagiotidis ◽  
Táňa Ravingerová ◽  
Antigone Lazou
Keyword(s):  
Oxidative Stress ◽  
Mrna Expression ◽  
Energy Production ◽  
Citrate Synthase ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Uncoupling Protein ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Isocitrate Dehydrogenase 2

Accumulating evidence support the cardioprotective properties of the nuclear receptor peroxisome proliferator activated receptor β/δ (PPARβ/δ); however, the underlying mechanisms are not yet fully elucidated. The aim of the study was to further investigate the mechanisms underlying PPARβ/δ-mediated cardioprotection in the setting of myocardial ischemia/reperfusion (I/R). For this purpose, rats were treated with PPARβ/δ agonist GW0742 and/or antagonist GSK0660 in vivo and hearts were subjected to ex vivo global ischemia followed by reperfusion. PPARβ/δ activation improved left ventricular developed pressure recovery, reduced infarct size (IS) and incidence of reperfusion-induced ventricular arrhythmias while it also up-regulated superoxide dismutase 2, catalase and uncoupling protein 3 resulting in attenuation of oxidative stress as evidenced by the reduction in 4-hydroxy-2-nonenal protein adducts and protein carbonyl formation. PPARβ/δ activation also increased both mRNA expression and enzymatic activity of aldehyde dehydrogenase 2 (ALDH2); inhibition of ALDH2 abrogated the IS limiting effect of PPARβ/δ activation. Furthermore, upregulation of PGC-1α and isocitrate dehydrogenase 2 mRNA expression, increased citrate synthase activity as well as mitochondrial ATP content indicated improvement in mitochondrial content and energy production. These data provide new mechanistic insight into the cardioprotective properties of PPARβ/δ in I/R pointing to ALDH2 as a direct downstream target and suggesting that PPARβ/δ activation alleviates myocardial I/R injury through coordinated stimulation of the antioxidant defense of the heart and preservation of mitochondrial function.

scholarly journals Overexpression of SP1 restores autophagy to alleviate acute renal injury induced by ischemia-reperfusion through the miR-205/PTEN/Akt pathway

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Chong Huang ◽  
Yan Chen ◽  
Bin Lai ◽  
Yan-Xia Chen ◽  
Cheng-Yun Xu ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Cell Apoptosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Akt Pathway ◽  
Acute Renal Injury ◽  
Injury Model ◽  
Renal Ischemia Reperfusion Injury

Abstract Background Acute kidney injury (AKI) is a major kidney disease with poor clinical outcome. SP1, a well-known transcription factor, plays a critical role in AKI and subsequent kidney repair through the regulation of various cell biologic processes. However, the underlying mechanism of SP1 in these pathological processes remain largely unknown. Methods An in vitro HK-2 cells with anoxia-reoxygenation injury model (In vitro simulated ischemic injury disease) and an in vivo rat renal ischemia-reperfusion injury model were used in this study. The expression levels of SP1, miR-205 and PTEN were detected by RT-qPCR, and the protein expression levels of SP1, p62, PTEN, AKT, p-AKT, LC3II, LC3I and Beclin-1 were assayed by western blot. Cell proliferation was assessed by MTT assay, and the cell apoptosis was detected by flow cytometry. The secretions of IL-6 and TNF-α were detected by ELISA. The targeted relationship between miR-205 and PTEN was confirmed by dual luciferase report assay. The expression and positioning of LC-3 were observed by immunofluorescence staining. TUNEL staining was used to detect cell apoptosis and immunohistochemical analysis was used to evaluate the expression of SP1 in renal tissue after ischemia-reperfusion injury in rats. Results The expression of PTEN was upregulated while SP1 and miR-205 were downregulated in renal ischemia-reperfusion injury. Overexpression of SP1 protected renal tubule cell against injury induced by ischemia-reperfusion via miR-205/PTEN/Akt pathway mediated autophagy. Overexpression of SP1 attenuated renal ischemia-reperfusion injury in rats. Conclusions SP1 overexpression restored autophagy to alleviate acute renal injury induced by ischemia-reperfusion through the miR-205/PTEN/Akt pathway.

Abstract P125: A Novel Role for Survivin in Insulin-induced Inhibition of Myocardial Apoptosis in Ischemic/reperfused Heart

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rui Si ◽  
Qiujun Yu ◽  
Ning Zhou ◽  
Ling Tao ◽  
Wenyi Guo ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Specific Inhibitor ◽  
Survivin Expression ◽  
Fold Increase ◽  
Tunel Staining ◽  
Sprague Dawley ◽  
Signaling Mechanism ◽  
Akt Phosphorylation ◽  
Apoptotic Effect

Objectives: Insulin reduces post-ischemic myocardial apoptotic death, but the mechanism remains unclear. Survivin, an anti-apoptotic protein has recently found participating in vascular repair. This study aimed to test the hypothesis that the up-regulation of survivin by insulin may play a role in the antiapoptotic and cardioprotective effects in the ischemic/reperfused (I/R) heart, and further investigate the signaling mechanism involved. Methods : Isolated adult Sprague-Dawley rat hearts were subjected to 30 min regional ischemia and 3 h of reperfusion. The hearts were randomized to receive insulin, insulin plus LY294002 (specific inhibitor of PI3K), or insulin plus rapamycin (specific inhibitor of mTOR) at the start of reperfusion. To further confirm the correlation between survivin and myocardial survival in vitro, cardiomyocytes were infected with adenovirus encoding survivin or transfected with siRNA targeting survivin. Phosphorylation of Akt, mTOR, p70S6K and the expression of protein survivin were determined and infarct size was assessed using TTC staining, cardiomyocytes apoptosis were evaluated after reperfusion by TUNEL staining and DNA laddering. Results: I/R increased myocardial survivin expression. Insulin reperfusion (10 −7 mol/L) resulted in a 4.2-fold increase in survivin expression (P<0.01 vs. I/R alone), which was almost completely blocked by LY294002. Both of the mTOR phosphorylation and survivin expression were inhibited in the group of insulin reperfusion plus LY294002. Rapamycin reperfusion did not change Akt phosphorylation but partially inhibited survivin expression (16.7±1.2 vs. 9.8±1.6, P<0.01 vs. I/R+Ins), which indicated a cardioprotective effect of survivin and a possible PI3K/Akt/mTOR/SVV signaling pathway during I/R. Moreover, over-expressed survivin provides protection against stimulated ischemia reperfusion induced cardiomyocyte apoptosis, while targeting survivin blunted the anti-apoptotic effect of insulin. Conclusion: This study demonstrates that insulin up-regulates myocardial survivin expression, partly at least, via PI3-kinase-mTOR mechanism, which contributes to the anti-apoptotic effect of insulin in the I/R heart.

Lin28 Enhances Glucose Metabolism in Human Placental Mesenchymal Stem Cells during Hypoxia via the PI3K-Akt Pathway

2021 ◽  
Author(s):  
Xi Zhou ◽  
Junbo Li ◽  
Jin Wang ◽  
Huifang Yang ◽  
Jingzeng Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Glucose Metabolism ◽  
Ischemia Reperfusion ◽  
Stem Cell Differentiation ◽  
Akt Signaling ◽  
Akt Pathway ◽  
Western Blots ◽  
Hypoxic Conditions

Abstract Mesenchymal stem cells (MSCs) are widely used to treat and prevent liver ischemia–reperfusion injury (LIRI), which commonly occurs after liver surgery. Lin28 is an RNA-binding protein crucial for early embryonic development, stem cell differentiation/reprogramming, tumorigenesis, and metabolism. However, whether Lin28 can enhance metabolism in human placental MSCs (PMSCs) during hypoxia to improve the protective effect against LIRI remains unclear. First, a Lin28 overexpression construct was introduced into PMSCs; glucose metabolism, the expression of glucose metabolism - and PI3K-AKT pathway-related proteins, and the levels of microRNA Let-7 family members were examined using a glucose metabolism kit, western blots, and real-time quantitative PCR, respectively. Next, treatment with an AKT inhibitor was performed to understand the association of Lin28 with the PI3K-Akt pathway. Subsequently, AML12 cells were co-cultured with PMSCs to construct an in vitro model of PMSC protecting liver cells from hypoxia injury. Finally, C57BL/6J mice were used to establish a partial warm hepatic ischemia–reperfusion model in vivo. Lin28 increased the glycolysis capacity of PMSCs, allowing these cells to produce more energy under hypoxic conditions. Lin28 also activated PI3K-Akt signaling under hypoxic conditions, and AKT inhibition attenuated the effects of Lin28. In addition, Lin28 overexpression was found to protect cells against LIRI-induced liver damage, inflammation, and apoptosis and attenuate hypoxia-induced hepatocyte injury. Inconclusion, Lin28 enhances glucose metabolism under hypoxic conditions in PMSCs, thereby providing protective effects against LIRI via the activation of the PI3K-Akt signaling pathway. Our study first reported the application of gene-modified mesenchymal stem cell-based therapy in LIRI.

Abstract 122: Cardiac mTOR Preserves Cardiac Function Following Ex Vivo Ischemia-Reperfusion in Diet-Induced Obese Mice

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Toshinori Aoyagi ◽  
Takashi Matsui
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Cardiac Function ◽  
Glucose Intolerance ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Heart Weight ◽  
Diabetic Patients ◽  
Significant Difference

The risk of heart failure following myocardial infarction is higher in diabetic patients than nondiabetic patients. The mammalian target of rapamycin (mTOR), a key downstream molecule of insulin-phosphoinositide 3-kinase (PI3K)-Akt signaling pathway, plays an important role in cardioprotection. However, the role of cardiac mTOR in ischemic injury in metabolic syndrome has not been well defined. To address this question, we studied the effect of overexpressing cardiac mTOR on cardiac function following ischemia/reperfusion (I/R) in mice with high-fat diet (HFD)-induced obesity. In this study, we used transgenic mice with cardiac-specific overexpression of mTOR (mTOR-Tg) as reported previously. mTOR-Tg and WT mice at 6 weeks old were fed HFD (60% fat by calories) ad libitum for 14 weeks. Control mTOR-Tg and WT mice were fed a normal chow diet (NCD). At 14 weeks after HFD, glucose and insulin tolerance tests demonstrated that HFD generated glucose intolerance and insulin resistance in both mTOR-Tg (n=20) and WT (n=24) mice. Body weight (BW) and heart weight (HW) were significantly higher in HFD mice than SCD mice (p<0.001 for BW in both strains; p<0.001 and p<0.01 for HW/tibia length, WT and mTOR-Tg, respectively) but there was no difference in BW or HW between HFD-mTOR-Tg and HFD-WT mice. Hearts from all four groups were subjected to global I/R (20 min ischemia, 40 min reperfusion) in the ex vivo Langendorff perfusion model. Baseline left ventricular developed pressure (LVDP) was higher in HFD mice than NCD mice in both strains [185.8 ± 10.7 vs. 143.6 ± 5.0 mmHg, HFD-WT (n=11) vs. NCD-WT (n=10) mice, p<0.01; 178.6 ± 10.1 vs. 135.0 ± 6.3, HFD-mTOR-Tg (n=8) vs. NCD-mTOR-Tg (n=11) mice, p<0.01]. Functional recovery after I/R was significantly lower in HFD-WT mice than NCD-WT mice (percent recovery of LVDP, 15.3 ± 5.4 vs. 44.6 ± 6.3 %, HFD-WT vs. NCD-WT mice, p<0.01). Intriguingly, there was no significant difference in LVDP recovery between HFD-mTOR-Tg and NCD-mTOR-Tg mice (36.5±10.8 vs. 58.8±6.0 %, HFD-mTOR-Tg vs. NCD-mTOR-Tg mice, n.s.). These findings suggest that cardiac mTOR is sufficient to substantially limit the metabolic syndrome-induced cardiac dysfunction following I/R in a mouse model of obesity with glucose intolerance and insulin resistance.

Thyroidectomy of SHR: effects on ventricular relaxation and on SR calcium uptake activity

1986 ◽  
Vol 250 (5) ◽  
pp. H861-H865 ◽  
Author(s):  
R. L. Rodgers ◽  
S. Black ◽  
S. Katz ◽  
J. H. McNeill
Keyword(s):  
Ventricular Hypertrophy ◽  
Calcium Uptake ◽  
Ex Vivo ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Mechanical Relaxation ◽  
Ventricular Relaxation ◽  
Uptake Activity ◽  
Wistar Kyoto

Ventricular hypertrophy and hypothyroidism are each characterized by impaired cardiac muscle relaxation and sarcoplasmic reticulum (SR) calcium uptake activity. A previous report also showed that hypothyroidism does not reverse ventricular hypertrophy (left-to-right ventricular weight ratios) of spontaneously hypertensive rats (SHR). We characterized the effects of thyroidectomy of 8 wk duration on relaxation of ejecting hearts and on SR calcium uptake activity from SHR and nonhypertrophic Wistar-Kyoto rat (WKY) controls. Relaxation was quantified by plotting maximum left ventricular pulse pressure (Pmax) vs. the area under the falling phase of the left ventricular pressure wave at three different pressure loads. Ventricles of euthyroid SHR were characterized by impaired relaxation and depressed SR calcium uptake activity compared with those of euthyroid WKY, confirming earlier studies. Thyroidectomy reduced ventricular relaxation and SR calcium uptake activities to about the same extent in SHR and WKY strains so that these measurements were most depressed in the SHR hypothyroid group. When all groups were considered, the extent of mechanical relaxation ex vivo and the rate of SR calcium uptake in vitro were well correlated.

Coronary smooth muscle reactivity to muscarinic stimulation after ischemia-reperfusion in porcine myocardial infarction

2003 ◽  
Vol 95 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Antonio Rodríguez-Sinovas ◽  
Josep Bis ◽  
Inocencio Anivarro ◽  
Javier de la Torre ◽  
Antoni Bayés-Genís ◽  
...  
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Coronary Blood Flow ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Severe Left Ventricular Dysfunction ◽  
Coronary Smooth Muscle

This study tested whether ischemia-reperfusion alters coronary smooth muscle reactivity to vasoconstrictor stimuli such as those elicited by an adventitial stimulation with methacholine. In vitro studies were performed to assess the reactivity of endothelium-denuded infarct-related coronary arteries to methacholine ( n = 18). In addition, the vasoconstrictor effects of adventitial application of methacholine to left anterior descending (LAD) coronary artery was assessed in vivo in pigs submitted to 2 h of LAD occlusion followed by reperfusion ( n = 12), LAD deendothelization ( n = 11), or a sham operation ( n = 6). Endothelial-dependent vasodilator capacity of infarct-related LAD was assessed by intracoronary injection of bradykinin ( n = 13). In vitro, smooth muscle reactivity to methacholine was unaffected by ischemia-reperfusion. In vivo, baseline methacholine administration induced a transient and reversible drop in coronary blood flow (9.6 ± 4.6 to 1.9 ± 2.6 ml/min, P < 0.01), accompanied by severe left ventricular dysfunction. After ischemia-reperfusion, methacholine induced a prolonged and severe coronary blood flow drop (9.7 ± 7.0 to 3.4 ± 3.9 ml/min), with a significant delay in recovery ( P < 0.001). Endothelial denudation mimics in part the effects of methacholine after ischemia-reperfusion, and intracoronary bradykinin confirmed the existence of endothelial dysfunction. Infarct-related epicardial coronary artery shows a delayed recovery after vasoconstrictor stimuli, because of appropriate smooth muscle reactivity and impairment of endothelial-dependent vasodilator capacity.

Sign in / Sign up

Export Citation Format

Share Document