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Wang C, Du HB, Zhao ZA, Zhai JY, Zhang LM, Niu CY, Zhao ZG. Autophagy Is Involved in Stellate Ganglion Block Reversing Posthemorrhagic Shock Mesenteric Lymph-Mediated Vascular Hyporeactivity. Front Physiol 2021; 12:728191. [PMID: 34621184 PMCID: PMC8491623 DOI: 10.3389/fphys.2021.728191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/23/2021] [Indexed: 12/05/2022] Open
Abstract
Objective: The aim of this study was to clarify the role of autophagy in stellate ganglion block (SGB) reversing posthemorrhagic shock mesenteric lymph (PHSML)-mediated vascular hyporeactivity. Methods: Hemorrhagic shock model in conscious rats was employed to observe the effects of SGB (0.2 ml of 0.25% ropivacaine hydrochloride hydrate) and autophagy inhibitor 3-methyladenine (3-MA; 30 mg/kg) on the vascular reactivity of second-order rat mesenteric arteries in vitro, while the effects of PHSML (1 ml/kg) and autophagy agonist rapamycin (Rapa, 10 mg/kg) on the beneficial effect of SGB were investigated. The cellular viability, contractility, and autophagy-related protein expressions in vascular smooth muscle cells (VSMCs) were detected following treatments of PHSML, PHSML obtained from the rats that underwent hemorrhagic shock plus SGB (PHSML-SGB), and PHSML plus 3-MA (5 mM), respectively. Results: Hemorrhagic shock significantly decreased the vascular reactivity to gradient norepinephrine (NE), which is reversed by the SGB treatment and 3-MA administration. On the contrary, PHSML intravenous infusion and Rapa administration inhibited the vascular contractile responses in rats that underwent hemorrhagic shock plus SGB treatment. PHSML treatment significantly inhibited the cellular viability and contractility in VSMCs, increased the expressions of LC3-II and Beclin 1, and decreased the expression of p62, along with opposite appearances in these indices following PHSML-SGB treatment. In addition, 3-MA counteracted the adverse roles of PHSML in these indices in VSMCs. Conclusion: SGB inhibits PHSML-mediated vascular hyporeactivity by reducing the excessive autophagy in VSMCs.
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Affiliation(s)
- Chen Wang
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China
| | - Hui-Bo Du
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China
| | - Zhen-Ao Zhao
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China.,Pathophysiology Experimental Teaching Center of Basic Medical College, Hebei North University, Zhangjiakou, China.,Key Laboratory of Critical Disease Mechanism and Intervention in Hebei, Hebei Medical University & Hebei North University, Shijiazhuang & Zhangjiakou, China
| | - Jia-Yi Zhai
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China
| | - Li-Min Zhang
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China.,Pathophysiology Experimental Teaching Center of Basic Medical College, Hebei North University, Zhangjiakou, China.,Key Laboratory of Critical Disease Mechanism and Intervention in Hebei, Hebei Medical University & Hebei North University, Shijiazhuang & Zhangjiakou, China
| | - Chun-Yu Niu
- Key Laboratory of Critical Disease Mechanism and Intervention in Hebei, Hebei Medical University & Hebei North University, Shijiazhuang & Zhangjiakou, China.,Basic Medical College, Hebei Medical University, Shijiazhuang, China
| | - Zi-Gang Zhao
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China.,Pathophysiology Experimental Teaching Center of Basic Medical College, Hebei North University, Zhangjiakou, China.,Key Laboratory of Critical Disease Mechanism and Intervention in Hebei, Hebei Medical University & Hebei North University, Shijiazhuang & Zhangjiakou, China
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Abstract
The microvasculature plays a central role in the pathophysiology of hemorrhagic shock and is also involved in arguably all therapeutic attempts to reverse or minimize the adverse consequences of shock. Microvascular studies specific to hemorrhagic shock were reviewed and broadly grouped depending on whether data were obtained on animal or human subjects. Dedicated sections were assigned to microcirculatory changes in specific organs, and major categories of pathophysiological alterations and mechanisms such as oxygen distribution, ischemia, inflammation, glycocalyx changes, vasomotion, endothelial dysfunction, and coagulopathy as well as biomarkers and some therapeutic strategies. Innovative experimental methods were also reviewed for quantitative microcirculatory assessment as it pertains to changes during hemorrhagic shock. The text and figures include representative quantitative microvascular data obtained in various organs and tissues such as skin, muscle, lung, liver, brain, heart, kidney, pancreas, intestines, and mesentery from various species including mice, rats, hamsters, sheep, swine, bats, and humans. Based on reviewed findings, a new integrative conceptual model is presented that includes about 100 systemic and local factors linked to microvessels in hemorrhagic shock. The combination of systemic measures with the understanding of these processes at the microvascular level is fundamental to further develop targeted and personalized interventions that will reduce tissue injury, organ dysfunction, and ultimately mortality due to hemorrhagic shock. Published 2018. Compr Physiol 8:61-101, 2018.
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Affiliation(s)
- Ivo Torres Filho
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas, USA
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Liu W, Chen P, Deng J, Lv J, Liu J. Resveratrol and polydatin as modulators of Ca 2+ mobilization in the cardiovascular system. Ann N Y Acad Sci 2017; 1403:82-91. [PMID: 28665033 DOI: 10.1111/nyas.13386] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 12/29/2022]
Abstract
In the cardiovascular system, Ca2+ controls cardiac excitation-contraction coupling and vascular contraction and dilation. Disturbances in intracellular Ca2+ homeostasis induce malfunctions of the cardiovascular system, including cardiac pump dysfunction, arrhythmia, remodeling, and apoptosis, as well as hypertension and impairment of vascular reactivity. Therefore, developing drugs and strategies manipulating Ca2+ handling are highly valued in the treatment of cardiovascular disease. Resveratrol (Res) and polydatin (PD), a Res glucoside, have been well established to have beneficial effects on improving cardiovascular function. Studies from our laboratory and others have demonstrated that they exhibit inotropic effects on normal heart and therapeutic effects on hypertension, cardiac ischemia/reperfusion injury, hypertrophy, and heart failure by manipulating Ca2+ mobilization. The actions of Res and PD on Ca2+ signals delicately manipulated by multiple Ca2+ -handling proteins are pleiotropic and somewhat controversial, depending on cellular species and intracellular oxidative status. Here, we focus on the effects of Res and PD on controlling Ca2+ homeostasis in the heart and vasculature under normal and diseased conditions and highlight the key direct and indirect molecules mediating these effects.
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Affiliation(s)
- Wenjuan Liu
- Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, China
| | - Peiya Chen
- Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, China
| | - Jianxin Deng
- Department of Endocrinology, the First Affiliated Hospital of Shenzhen University, Shenzhen University, Shenzhen, China.,Department of Endocrinology, Shenzhen No. 2 People's Hospital, Shenzhen, China
| | - Jingzhang Lv
- Shenzhen Entry-Exit Inspection and Quarantine Bureau, Shenzhen, China
| | - Jie Liu
- Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, China
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Activation of sirtuin 1/3 improves vascular hyporeactivity in severe hemorrhagic shock by alleviation of mitochondrial damage. Oncotarget 2016; 6:36998-7011. [PMID: 26473372 PMCID: PMC4741911 DOI: 10.18632/oncotarget.6076] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/24/2015] [Indexed: 12/11/2022] Open
Abstract
Vascular hyporeactivity is one of the major causes responsible for refractory hypotension and associated mortality in severe hemorrhagic shock. Mitochondrial permeability transition (mPT) pore opening in arteriolar smooth muscle cells (ASMCs) is involved in the pathogenesis of vascular hyporeactivity. However, the molecular mechanism underlying mitochondrial injury in ASMCs during hemorrhagic shock is not well understood. Here we produced an in vivo model of severe hemorrhagic shock in adult Wistar rats. We found that sirtuin (SIRT)1/3 protein levels and deacetylase activities were decreased in ASMCs following severe shock. Immunofluorescence staining confirmed reduced levels of SIRT1 in the nucleus and SIRT3 in the mitochondria, respectively. Acetylation of cyclophilin D (CyPD), a component of mPT pore, was increased. SIRT1 activators suppressed mPT pore opening and ameliorated mitochondrial injury in ASMCs after severe shock. Furthermore, administration of SIRT1 activators improved vasoreactivity in rats under severe shock. Our data suggest that epigenetic mechanisms, namely histone post-translational modifications, are involved in regulation of mPT by SIRT1/SIRT3- mediated deacetylation of CyPD. SIRT1/3 is a promising therapeutic target for the treatment of severe hemorrhagic shock.
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Zeng Z, Chen Z, Li T, Zhang J, Gao Y, Xu S, Cai S, Zhao KS. Polydatin: a new therapeutic agent against multiorgan dysfunction. J Surg Res 2015. [DOI: 10.10.1016/j.jss.2015.05.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Zeng Z, Chen Z, Li T, Zhang J, Gao Y, Xu S, Cai S, Zhao KS. Polydatin: a new therapeutic agent against multiorgan dysfunction. J Surg Res 2015; 198:192-9. [PMID: 26095424 DOI: 10.1016/j.jss.2015.05.041] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 05/03/2015] [Accepted: 05/21/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND Polydatin (PD), a monocrystalline and polyphenolic drug isolated from a traditional Chinese herb (Polygonum cuspidatum), is protective against mitochondrial dysfunction and has been approved for clinical trials in the treatment of shock. However, whether the administration of PD has a therapeutic effect on multiple-organ dysfunction syndrome (MODS) requires investigation. MATERIAL AND METHODS MODS was induced in Sprague-Dawley rats via hemorrhage and ligation and puncture of cecum-induced sepsis. The rats were divided into three groups as follows: MODS + PD, MODS + normal saline, and a control group (no treatment). Survival time, blood biochemical indexes, and histopathologic changes in various organs were evaluated; serum oxidative stress (advanced oxidative protein products [AOPPs]) and proinflammatory cytokines (tumor necrosis factor-α, interleukin 1β, and interleukin 6) were assayed using enzyme-linked immunosorbent assay. Apoptosis-related protein expression (B-cell lymphoma-2 [Bcl-2] and Bax) was assayed by immunohistochemical and Western blotting methods, whereas caspase-3 activity was assayed by spectrophotometry. RESULTS PD improved organ function, prolonged survival time, and reduced MODS incidence and serum levels of AOPPs and proinflammatory cytokines. It also decreased Bax levels and caspase-3 activity and increased Bcl-2 levels in the kidney and liver. CONCLUSIONS PD may serve as a potential therapeutic for MODS, as it suppresses oxidative stress, inhibits inflammatory response, attenuates apoptosis, and protects against mitochondrial dysfunction.
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Affiliation(s)
- Zhenhua Zeng
- Guangdong Key Laboratory of Shock and Microcirculation Research, Department of Pathophysiology, Southern Medical University, Guangzhou, P.R. China; Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Zhongqing Chen
- Guangdong Key Laboratory of Shock and Microcirculation Research, Department of Pathophysiology, Southern Medical University, Guangzhou, P.R. China; Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Tao Li
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Junli Zhang
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Youguang Gao
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China; Department of Anesthesiology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, P.R. China
| | - Siqi Xu
- Guangdong Key Laboratory of Shock and Microcirculation Research, Department of Pathophysiology, Southern Medical University, Guangzhou, P.R. China
| | - Shumin Cai
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Ke-seng Zhao
- Guangdong Key Laboratory of Shock and Microcirculation Research, Department of Pathophysiology, Southern Medical University, Guangzhou, P.R. China.
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Postshock mesenteric lymph drainage ameliorates vascular reactivity and calcium sensitivity through RhoA. J Surg Res 2014; 186:304-9. [DOI: 10.1016/j.jss.2013.08.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/14/2013] [Accepted: 08/16/2013] [Indexed: 01/27/2023]
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Zhao ZG, Wei YL, Niu CY, Zhang YP, Zhang LM, Jiang LN. Role of protein kinase G on the post-shock mesenteric lymph blockage ameliorating vascular calcium sensitivity. Acta Cir Bras 2013; 28:537-42. [DOI: 10.1590/s0102-86502013000700010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/24/2013] [Indexed: 11/22/2022] Open
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Mesenteric Lymph Return Is an Important Contributor to Vascular Hyporeactivity and Calcium Desensitization After Hemorrhagic Shock. Shock 2012; 38:186-95. [DOI: 10.1097/shk.0b013e31825f1c9b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Suppressive effect of low-level laser therapy on tracheal hyperresponsiveness and lung inflammation in rat subjected to intestinal ischemia and reperfusion. Lasers Med Sci 2012; 28:551-64. [PMID: 22562449 DOI: 10.1007/s10103-012-1088-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 03/15/2012] [Indexed: 10/28/2022]
Abstract
Intestinal ischemia and reperfusion (i-I/R) is an insult associated with acute respiratory distress syndrome (ARDS). It is not known if pro- and anti-inflammatory mediators in ARDS induced by i-I/R can be controlled by low-level laser therapy (LLLT). This study was designed to evaluate the effect of LLLT on tracheal cholinergic reactivity dysfunction and the release of inflammatory mediators from the lung after i-I/R. Anesthetized rats were subjected to superior mesenteric artery occlusion (45 min) and killed after clamp release and preestablished periods of intestinal reperfusion (30 min, 2 or 4 h). The LLLT (660 nm, 7.5 J/cm(2)) was carried out by irradiating the rats on the skin over the right upper bronchus for 15 and 30 min after initiating reperfusion and then euthanizing them 30 min, 2, or 4 h later. Lung edema was measured by the Evans blue extravasation technique, and pulmonary neutrophils were determined by myeloperoxidase (MPO) activity. Pulmonary tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), intercellular adhesion molecule-1 (ICAM-1), and isoform of NO synthase (iNOS) mRNA expression were analyzed by real-time PCR. TNF-α, IL-10, and iNOS proteins in the lung were measured by the enzyme-linked immunoassay technique. LLLT (660 nm, 7.5 J/cm(2)) restored the tracheal hyperresponsiveness and hyporesponsiveness in all the periods after intestinal reperfusion. Although LLLT reduced edema and MPO activity, it did not do so in all the postreperfusion periods. It was also observed with the ICAM-1 expression. In addition to reducing both TNF-α and iNOS, LLLT increased IL-10 in the lungs of animals subjected to i-I/R. The results indicate that LLLT can control the lung's inflammatory response and the airway reactivity dysfunction by simultaneously reducing both TNF-α and iNOS.
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Wang X, Song R, Bian HN, Brunk UT, Zhao M, Zhao KS. Polydatin, a natural polyphenol, protects arterial smooth muscle cells against mitochondrial dysfunction and lysosomal destabilization following hemorrhagic shock. Am J Physiol Regul Integr Comp Physiol 2012; 302:R805-14. [PMID: 22277937 DOI: 10.1152/ajpregu.00350.2011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The main objective of this study was to investigate the activity of polydatin on mitochondrial dysfunction and lysosomal stability of arteriolar smooth muscle cells (ASMCs) in severe shock. The experimental animals (rats) were divided into five groups: control, hemorrhagic shock, shock + CsA, shock + Res, and shock + PD (exposed to cyclosporin A, resveratrol, or polydatin following induction of hemorrhagic shock, respectively). The calcein-Co(2+) technique revealed opening of ASMC mitochondrial permeability transition pores (mPTP) after shock with resulting mitochondrial swelling, decreased mitochondrial membrane potential (ΔΨm), and reduced intracellular ATP levels. These alterations were all inhibited by exposure to PD, which was significantly more effective than CsA and Res. PD also preserved lysosomal stability, suppressed activation of K(ATP) channels, ASMC hyperpolarization, and reduced vasoresponsiveness to norepinephrine that normally follows severe shock. The results demonstrate that exposure to PD after initiation of severe shock effectively preserves ASMC mitochondrial integrity and has a significant therapeutic effect in severe shock. The effects may partially result from lysosomal stabilization against shock-induced oxidative stress and depressed relocation of hydrolytic enzymes and redox-active lysosomal iron that, in turn, may induce mPTP opening.
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Affiliation(s)
- Xingmin Wang
- Guangdong Key Laboratory of Shock and Microcirculation Research, Dept. of Pathophysiology, Southern Medical Univ., Guangzhou, P. R. China
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Abstract
We used isolated superior mesenteric arteries (SMAs) from hemorrhagic-shock rats and hypoxia-treated vascular smooth muscle cells (VSMCs; mimicking the shock state) to observe the effects of platelet-derived growth factor (PDGF; Rac1 stimulator) and NSC23766 (Rac1 antagonist) on vascular reactivity and the relationship with the Rho kinase-myosin light-chain phosphatase (MLCP) and p21-activated kinase (PAK)-myosin light-chain kinase (MLCK) signal pathway. The results indicated that the contractile responses of the SMAs and VSMCs were significantly increased at early shock or after transient hypoxia. NSC23766 (Rac1 antagonist) further increased, whereas PDGF (Rac1 stimulator) decreased the contractile responses of SMAs and VSMCs. In the late period of shock or prolonged hypoxia, the contractile responses of SMAs and VSMCs were significantly decreased; NSC23766 increased (whereas PDGF further decreased) the contractile response of the SMAs and VSMCs. Activation of Rac1 with PDGF significantly increased the activity of PAK and MLCP, and decreased Rho kinase and MLCK activity and 20-kDa myosin light-chain phosphorylation in VSMCs. The PAK inhibitor PAK-18 significantly antagonized the PDGF-induced decrease in MLCK activity, whereas the Rho kinase antagonist Y-27632 further enforced the PDGF-induced increase in MLCP activity. Simple fluid resuscitation did not improve but in combination with NSC23766 significantly improved vascular reactivity and animal survival at 24 hours. This suggested that Rac1 has an inhibitory effect on vasoreactivity after shock. Rac1-mediated regulation of vascular reactivity is mainly through activation of PAK, inhibition of MLCK and inhibition of Rho kinase, unpack the inhibition of Rho kinase to MLCP. Rac1 may be a potential target to treat vascular hyporeactivity in many critical conditions.
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Effects of Ischemic Preconditioning on Vascular Reactivity and Calcium Sensitivity After Hemorrhagic Shock and Their Relationship to the Rho A-Rho-kinase Pathway in Rats. J Cardiovasc Pharmacol 2011; 57:231-9. [DOI: 10.1097/fjc.0b013e318204a910] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Mitochondrial injury underlies hyporeactivity of arterial smooth muscle in severe shock. Am J Hypertens 2011; 24:45-51. [PMID: 20940715 DOI: 10.1038/ajh.2010.184] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Our previous data showed membrane hyperpolarization of arteriolar smooth muscle cells (ASMCs) caused by adenosine triphosphate (ATP)-sensitive potassium channels (K(ATP)) activation contributed to vascular hyporeactivity in shock. Despite supply of oxygen and nutrients, vascular hyporeactivity to vasoconstrictor agents still remains, which may result from low ATP level. The study was designed to investigate shock-induced mitochondrial changes of rat ASMCs in the genesis and treatment of hypotension in severe shock. METHODS The animals were divided into four groups: controls, hemorrhagic shock, CsA+shock (preadministration of cyclosporin A before bleeding), and ATR+CsA+shock (preadministration of atractyloside, followed by CsA and bleeding). ASMCs were isolated and the ultrastructure and function of ASMC mitochondria and the vasoresponsiveness to norepinephrine (NE) was measured on microcirculatory preparations. RESULTS Ultrastructurally, the hemorrhagic shock group showed swollen mitochondria with poorly defined cristae. In this group, the number of ASMCs with low mitochondrial membrane potential (Δψ(m)) was increased by 49.7%, and the intracellular ATP level was reduced by 82.1%, which led to activation of K(ATP) plasma membrane channels with resultant ASMC hyperpolarization and low vasoreactivity. These changes were reduced in the CsA+shock group. When mitochondrial damage was aggravated by ATR in the ATR+CsA+shock group, the CsA did not protect. Compared to the shock group, vasoresponsiveness to NE was much improved in the CsA+shock group. CONCLUSIONS Mitochondrial ASMC dysfunction is involved in the genesis of reduced vasoreactivity in severe shock. Mitochondrial protection may therefore be a new approach in the treatment of shock-induced hypotension.
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Abstract
BACKGROUND The reduced vascular reactivity after severe trauma or shock played an important role in the development and outcome of shock. Our previous study showed that protein kinase C (PKC) took part in the regulation of vascular reactivity after hemorrhagic shock. The objective of this study was to investigate the protective effects of activation of PKC on hemorrhagic shock and its related mechanism. METHODS Sprague dawley rats were subjected to hemorrhagic shock (40 mm Hg for 2 hours). Effects of the PKC agonist, phorbol-12-myristate-13-acetate (PMA), and its inhibitor, staurosporine, on hemodynamic parameters were observed in vivo or in vitro. The hemodynamic parameters included mean arterial blood pressure, left intraventricular systolic pressure, the maximal change rate of left intraventricular pressure (+/-dp/dtmax), blood gases including pH, Po2, Sao2, and base excess, animal survival time, the vascular reactivity and calcium sensitivity of superior mesenteric artery, and mitochondrial function and blood flow of liver and kidney. RESULTS Intravenous administration of PKC agonist, PMA, at the concentration of 1 microg/kg significantly increased the mean arterial blood pressure, left intraventricular systolic pressure, +/-dp/dtmax, the pressor effect, and the contractile response of norepinephrine, it also improved the blood gases, and prolonged the survival time of shocked rats. In addition, the intravenous administration of PMA improved mitochondrial function and liver and kidney blood flow. A total of 10(-7) mol/L of PMA administrated in vitro significantly improved the vascular reactivity and calcium sensitivity of superior mesenteric artery to norepinephrine and Ca2+. These effects of PMA were abolished by the PKC specific inhibitor staurosporine (1 microg/kg in vivo or 10(-7) mol/L in vitro). CONCLUSION Activation of PKC has protective effects on hemorrhagic shock. The mechanism is related not only to its hemodynamic stabilization effect via improving vascular reactivity and calcium sensitivity but also to its effect on improving the perfusion and mitochondrial function of vital organs.
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Adenosine triphosphate-sensitive potassium channels prevent extension of myocardial ischemia to subepicardium during hemorrhagic shock. Shock 2008; 30:178-83. [PMID: 18091571 DOI: 10.1097/shk.0b013e318160d990] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cardiac dysfunction during hemorrhagic shock (HS) is associated with myocardial ischemia, during which adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channels can be activated. We investigated the role of K(ATP) channels in HS-induced myocardial ischemia. Canine HS was induced using an aortic reservoir to maintain the aortic pressure at a constant 40 mmHg. To visualize the myocardial ischemia as a nicotinamide adenine dinucleotide (NADH) - fluorescent area, the beating hearts were rapidly cross-sectioned (120 ms) and freeze-clamped (-190 degrees C) using a sampling device after 10 min of HS. The effect of a K(ATP) channel blocker, glibenclamide (1 mg/kg, i.v.), on myocardial ischemia was also quantified. Regional myocardial blood flow was measured using heavy element-loaded nonradioactive microspheres. Myocardial ischemia developed in the subendocardium in the HS alone group, whereas it extended through all the cardiac layers in the glibenclamide-treatment group. The coadministration of a K(ATP) channel opener, cromakalim (50 microg/kg, i.v.), with glibenclamide prevented the extension of myocardial ischemia to the subepicardium. Glibenclamide decreased the myocardial ATP concentration selectively in the subepicardium during HS. The HS decreased myocardial blood flow transmurally, and following the administration of glibenclamide, further decreased the blood flow selectively in the subepicardium. These results suggest that K(ATP) channels are activated during HS, enabling selective subepicardial coronary dilatation and protecting the myocardium from the extension of myocardial ischemia to the subepicardium.
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Beneficial effect of arginine vasopressin on hemorrhagic shock through improving the vascular reactivity. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11684-008-0047-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Zhao Q, Zhao KS. Inhibition of L-type calcium channels in arteriolar smooth muscle cells is involved in the pathogenesis of vascular hyporeactivity in severe shock. Shock 2008; 28:717-721. [PMID: 17607159 DOI: 10.1097/shk.0b013e318050c914] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The objective was to investigate the changes in the function of L-type calcium (L-Ca2+) channels of arteriolar smooth muscle cells (ASMCs) in the genesis of vascular hyporeactivity during severe shock. A hemorrhagic shock (HS) model was reproduced in rats, and the responsiveness of arterioles in the cremaster muscle to norepinephrine (NE) was measured. The inward currents of L-Ca2+ channel and intracellular concentration of Ca2+ ([Ca2+]i) level in isolated ASMCs were measured using patch clamp and fluorescent probe techniques. The arteriolar vasoreactivity was significantly reduced with a 12.5-fold increase of NE threshold level 2 h post-HS. Meanwhile, the inward currents through L-Ca2+ channels of ASMCs were significantly decreased at different holding potentials, and the maximal inward current was only 26.7% of control value in the shock group. The increased intracellular concentration of Ca2+ level of ASMCs stimulated by NE was reduced to 32.0% of control value 2 h post-HS. Administration of the L-Ca2+ channel stimulator, Bay K8644, partially restored the NE threshold level and transiently increased the mean arterial pressure during HS, lending further support to the importance of ASMC L-Ca2+ channel inhibition in the genesis of low vasoreactivity in vivo during severe shock. Our results suggest that stimulation of L-Ca2+ channels of ASMCs might be a potential therapeutic approach for treatment of refractory hypotension in severe shock.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Arterioles/cytology
- Arterioles/drug effects
- Arterioles/metabolism
- Calcium/metabolism
- Calcium Channels, L-Type/physiology
- Membrane Potentials/drug effects
- Microscopy, Confocal
- Models, Biological
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/physiology
- Norepinephrine/pharmacology
- Patch-Clamp Techniques
- Rats
- Rats, Wistar
- Shock, Hemorrhagic/metabolism
- Shock, Hemorrhagic/physiopathology
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Affiliation(s)
- Qing Zhao
- Guangdong Province Key Laboratory of Shock and Microcirculation Research, Department of Pathophysiology, Southern Medical University, Guangzhou, China
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Li T, Liu L, Liu J, Ming J, Xu J, Yang G, Zhang Y. Mechanisms of Rho kinase regulation of vascular reactivity following hemorrhagic shock in rats. Shock 2008; 29:65-70. [PMID: 17666953 DOI: 10.1097/shk.0b013e318063e477] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our previous research showed that Rho kinase took part in the regulation of vascular hyporeactivity after shock. The objective of the present study was to investigate its mechanism. With isolated superior mesenteric artery (SMA) from hemorrhagic shock rats, we studied the relationship of Rho kinase regulating vascular reactivity to calcium sensitivity and myosin light chain phosphatase (MLCP) and myosin light chain kinase (MLCK). The vascular reactivity and calcium sensitivity of SMA were observed by measuring the contraction initiated by accumulative norepinephrine (NE) and calcium under depolarizing condition (120 mM K(+)) with an isolated organ perfusion system. Hypoxia-treated vascular smooth muscle cells (VSMCs) were used to study the effects of Rho kinase on the activity of MLCP and MLCK and the phosphorylation of 20-kDa myosin light chain (MLC(20)). Myosin light chain (20 kDa) phosphorylation of VSMC in mesenteric artery was detected by immunoprecipitation and Western blotting. The activity of MLCP and MLCK was assayed by enzymatic catalysis. The contractile response of VSMC was measured by the ratio of accumulative infiltration of fluorescent isothiocyanate-conjugated bovine serum albumin through transwell. The results indicated that the vascular reactivity and calcium sensitivity of SMA to NE and calcium following hemorrhagic shock and the contractile response of VSMC to NE following hypoxia were significantly decreased. Angiotensin II (Ang-II), the Rho kinase stimulator, significantly improved hypoxia or hemorrhagic shock-induced decrease of vascular reactivity and calcium sensitivity. These effects of Ang-II on vascular reactivity were abolished by Y-27632, the specific Rho kinase inhibitor. Calyculin A, the MLCP inhibitor, further enhanced Ang-II-induced increase of calcium sensitivity, but ML-9, the MLCK inhibitor, had no effect. Further studies showed Ang-II reversed the hypoxia-induced increase of MLCP activity and increased the hypoxia-induced decrease of MLC(20) phosphorylation in VSMC. It was suggested that Rho kinase played an important role in the regulation of vascular reactivity after hemorrhagic shock. The mechanisms may be related to its calcium sensitivity regulation. Rho kinase up-regulates calcium sensitivity of VSMC possibly through inhibiting the activity of MLCP and increasing the phosphorylation of MLC(20).
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Affiliation(s)
- Tao Li
- State Key Laboratory of Trauma, Burns and Combined Injury, The 2nd Department of Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing, PR China.
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21
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Morelli A, Lange M, Ertmer C, Broeking K, Van Aken H, Orecchioni A, Rocco M, Bachetoni A, Traber DL, Landoni G, Pietropaoli P, Westphal M. Glibenclamide dose response in patients with septic shock: effects on norepinephrine requirements, cardiopulmonary performance, and global oxygen transport. Shock 2007; 28:530-5. [PMID: 17589379 DOI: 10.1097/shk.0b013e3180556a3c] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Adenosine triphosphate-sensitive potassium channels are important regulators of arterial vascular smooth muscle tone and are implicated in the pathophysiology of catecholamine tachyphylaxis in septic shock. The present study was designed as a prospective, randomized, double-blinded, clinical pilot study to determine whether different doses of glibenclamide have any effects on norepinephrine requirements, cardiopulmonary hemodynamics, and global oxygen transport in patients with septic shock. We enrolled 30 patients with septic shock requiring invasive hemodynamic monitoring and norepinephrine infusion of 0.5 microg.kg-1.min-1 or greater to maintain MAP between 65 and 75 mmHg. In addition to standard therapy, patients were randomized to receive either 10, 20, or 30 mg of enteral glibenclamide. Systemic hemodynamics, global oxygen transport including arterial lactate concentrations, gas exchange, plasma glucose concentrations, and electrolytes were determined at baseline and after 3, 6, and 12 h after administration of the study drug. Glibenclamide decreased plasma glucose concentrations in a dose-dependent manner but failed to reduce norepinephrine requirements. None of the doses had any effects on cardiopulmonary hemodynamics, global oxygen transport, gas exchange, or electrolytes. These data suggest that oral glibenclamide in doses from 10 to 30 mg fails to counteract arterial hypotension and thus to reduce norepinephrine requirements in catecholamine-dependent human septic shock.
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MESH Headings
- Adenosine Triphosphate/metabolism
- Aged
- Biological Transport/drug effects
- Blood Glucose/analysis
- Catecholamines/metabolism
- Dose-Response Relationship, Drug
- Double-Blind Method
- Female
- Glyburide/administration & dosage
- Hemodynamics/drug effects
- Humans
- Hypoglycemic Agents/administration & dosage
- Hypotension
- Lactic Acid/blood
- Lung/metabolism
- Lung/physiopathology
- Male
- Middle Aged
- Monitoring, Physiologic
- Muscle Tonus/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Norepinephrine/administration & dosage
- Oxygen/metabolism
- Pilot Projects
- Potassium Channels/metabolism
- Pulmonary Gas Exchange/drug effects
- Shock, Septic/blood
- Shock, Septic/drug therapy
- Shock, Septic/pathology
- Shock, Septic/physiopathology
- Vasoconstrictor Agents/administration & dosage
- Water-Electrolyte Balance/drug effects
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Affiliation(s)
- Andrea Morelli
- Department of Anesthesiology and Intensive Care, University of Rome, La Sapienza, Rome, Italy.
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22
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Zhao G, Zhao Y, Pan B, Liu J, Huang X, Zhang X, Cao C, Hou N, Wu C, Zhao KS, Cheng H. Hypersensitivity of BK
Ca
to Ca
2+
Sparks Underlies Hyporeactivity of Arterial Smooth Muscle in Shock. Circ Res 2007; 101:493-502. [PMID: 17641230 DOI: 10.1161/circresaha.107.157271] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Large conductance Ca
2+
-activated K
+
channels (BK
Ca
) play a critical role in blood pressure regulation by tuning the vascular smooth muscle tone, and hyposensitivity of BK
Ca
to Ca
2+
sparks resulting from its altered β1 subunit stoichiometry underlies vasoconstriction in animal models of hypertension. Here we demonstrate hypersensitivity of BK
Ca
to Ca
2+
sparks that contributes to hypotension and blunted vasoreactivity in acute hemorrhagic shock. In arterial smooth muscle cells under voltage-clamp conditions (0 mV), the amplitude and duration, but not the frequency, of spontaneous transient outward currents of BK
Ca
origin were markedly enhanced in hemorrhagic shock, resulting in a 265% greater hyperpolarizing current. Concomitantly, subsurface Ca
2+
spark frequency was either unaltered (at 0 mV) or decreased in hyperpolarized resting cells. Examining the relationship between spark and spontaneous transient outward current amplitudes revealed a hypersensitive BK
Ca
activity to Ca
2+
spark in hemorrhagic shock, whereas the spark–spontaneous transient outward current coupling fidelity was near unity in both groups. Importantly, we found an acute upregulation of the β1 subunit of the channel, and single-channel recording substantiated BK
Ca
hypersensitivity at micromolar Ca
2+
, which promotes the α and β1 subunit interaction. Treatment of shock animals with the BK
Ca
inhibitors iberiotoxin and charybdotoxin partially restored vascular membrane potential and vasoreactivity to norepinephrine and blood reinfusion. Thus, the results underscore a dynamic regulation of the BK
Ca
–Ca
2+
spark coupling and its therapeutic potential in hemorrhagic shock–associated vascular disorders.
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Affiliation(s)
- Guiling Zhao
- Department of Pathophysiology, Southern Medical University, Guangzhou, China
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23
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Tamayo L. Bloqueo de los canales de potasio en el shock séptico, ¿otra esperanza perdida? Med Intensiva 2007; 31:251-7. [PMID: 17580016 DOI: 10.1016/s0210-5691(07)74818-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L Tamayo
- Unidad de Cuidados Intensivos, Complejo Hospitalario, Palencia.
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24
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Peckham RM, Handrigan MT, Bentley TB, Falabella MJ, Chrovian AD, Stahl GL, Tsokos GC. C5-blocking antibody reduces fluid requirements and improves responsiveness to fluid infusion in hemorrhagic shock managed with hypotensive resuscitation. J Appl Physiol (1985) 2007; 102:673-80. [PMID: 17068213 DOI: 10.1152/japplphysiol.00917.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypotensive resuscitation strategies and inhibition of complement may both be of benefit in hemorrhagic shock. We asked if C5-blocking antibody (anti-C5) could diminish the amount of fluid required and improve responsiveness to resuscitation from hemorrhage. Awake, male Sprague-Dawley rats underwent controlled hemorrhage followed by prolonged (3 h) hypotensive resuscitation with lactated Ringer’s or Hextend, with or without anti-C5. Anti-C5 treatment led to an estimated 62.3 and 58.5% reduction in the volume of Hextend and lactated Ringer’s, respectively. In the subgroup of animals with a positive mean arterial pressure (MAP) response to fluid infusion following prolonged hypotension, anti-C5 treatment led to an estimated 4.7- and 4.1-fold increase in mean arterial pressure response per unit Hextend and lactated Ringer’s infused, respectively. We observed no significant postresuscitation metabolic differences between the anti-C5 groups and controls. Whether anti-C5 could serve as a volume-sparing adjunct that improves responsiveness to fluid administration in humans deserves further study.
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Affiliation(s)
- Russell M Peckham
- Department of Cellular Injury, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.
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25
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Yang G, Liu L, Xu J, Li T. Effect of arginine vasopressin on vascular reactivity and calcium sensitivity after hemorrhagic shock in rats and its relationship to Rho-kinase. ACTA ACUST UNITED AC 2007; 61:1336-42. [PMID: 17159674 DOI: 10.1097/01.ta.0000197928.99745.22] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Our previous study showed that vascular smooth muscle was desensitized to calcium after hemorrhagic shock, which is associated with the development of vascular hyporeactivity. Arginine vasopressin (AVP) can constrict blood vessels by the activation of Rho-kinase and had a beneficial effect on endotoxic and hemorrhagic shock. The present study investigated the effects of AVP on vascular reactivity and calcium sensitivity after hemorrhagic shock in rats and its relations with Rho-kinase. METHODS Experiments were conducted in vivo and in vitro. In vivo, anesthetized Wistar rats were hemorrhaged to and maintained at a mean arterial pressure (MAP) of 30 mm Hg for 2 hours. The effect of AVP (0.1 and 0.4 U/kg) on the pressor effect of norepinephrine (NE, 3 microg/kg) and contractile response of the superior mesenteric artery (SMA) to NE were observed. In vitro, SMA from hemorrhaged rats was used to evaluate the effects of AVP on vascular reactivity and calcium sensitivity and its relationship with Rho-kinase. Vascular reactivity was determined by observing the contractile response of the SMA to NE and calcium sensitivity was determined by observing the contractile response of the SMA to Ca2+ under depolarizing conditions (120 mmol/L K+). RESULTS In vivo NE-induced pressor response and contraction of the SMA after hemorrhagic shock were significantly decreased. AVP (0.4 U/kg) significantly increased the pressor response of NE and the contractile response of the SMA to NE. In vitro, the contractile response of SMA to NE and Ca after hemorrhagic shock was significantly decreased as compared with the control group. AVP pretreatment significantly increased the contractile response of SMA to NE and Ca2+ and made the cumulative dose-response curve of NE and Ca2+ shift to the left. HA-1077, the Rho-kinase antagonist, prevented AVP-induced leftward shift of the dose-response curve of NE and Ca2+. CONCLUSIONS AVP can increase the vascular reactivity and calcium sensitivity of SMA in hemorrhagic shock rats. Action of AVP appears to be regulated through a Rho-kinase signaling pathway.
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Affiliation(s)
- Guangming Yang
- State Key Laboratory of Trauma, Burns and Combined Injury Department, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing, PR China
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26
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Li T, Liu L, Xu J, Yang G, Ming J. CHANGES OF RHO KINASE ACTIVITY AFTER HEMORRHAGIC SHOCK AND ITS ROLE IN SHOCK-INDUCED BIPHASIC RESPONSE OF VASCULAR REACTIVITY AND CALCIUM SENSITIVITY. Shock 2006; 26:504-9. [PMID: 17047522 DOI: 10.1097/01.shk.0000228796.41044.41] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of the present study is to investigate the changes of Rho kinase activity and its role in biphasic response of vascular reactivity and calcium sensitivity after hemorrhagic shock. The vascular reactivity and calcium sensitivity of superior mesenteric artery (SMA) from hemorrhagic shock rats were determined via observing the contraction initiated by norepinephrine (NE) and Ca under depolarizing conditions (120 mmol/L K) with isolated organ perfusion system. At same time, Rho kinase activity in mesenteric artery was measured, and the effects of Rho kinase activity-regulating agents, angiotensin II (Ang-II), insulin, and Y-27632, on vascular reactivity and calcium sensitivity were also observed. The results indicated that the vascular reactivity and calcium sensitivity were increased at early shock (immediate and 30 min after shock) and decreased at late shock (1 and 2 h after shock). The maximal contractions of NE and Ca were significantly increased (P < 0.05 or P < 0.01) at early shock. But they were significantly decreased at late shock (P < 0.05 or P < 0.01). Rho kinase activity was significantly increased at early shock (immediate after shock) (P < 0.05) but significantly decreased at 1 and 2 h after shock (P < 0.05 or P < 0.01). It was positively correlated with the changes of vascular reactivity and calcium sensitivity. Insulin decreased the increased contractile response of SMA to NE and Caat early shock (P < 0.05 or P < 0.01). Angiotensin II increased the decreased contractile response of SMA to NE and Ca at 2-h shock (P < 0.05 or P < 0.01); Y-27632, Rho kinase-specific antagonist, decreased the contractile response of SMA to NE and Ca at 2-h shock, and abolished Ang-II induced the increase of vascular reactivity and calcium sensitivity. The results suggest that Rho kinase may be involved in the biphasic change of vascular reactivity and calcium sensitivity after hemorrhagic shock. Rho kinase may regulate vascular reactivity through the regulation of calcium sensitivity. Rho kinase-regulating agents may have some beneficial effects on shock-induced vascular hyporeactivity.
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MESH Headings
- Amides
- Angiotensins/pharmacology
- Animals
- Calcium/metabolism
- Enzyme Inhibitors/pharmacology
- In Vitro Techniques
- Insulin/pharmacology
- Mesenteric Artery, Superior/metabolism
- Mesenteric Artery, Superior/physiopathology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Pyridines
- Rats
- Rats, Wistar
- Shock, Hemorrhagic/metabolism
- Shock, Hemorrhagic/physiopathology
- rho GTP-Binding Proteins/antagonists & inhibitors
- rho GTP-Binding Proteins/drug effects
- rho GTP-Binding Proteins/metabolism
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Affiliation(s)
- Tao Li
- State Key Laboratory of Trauma, Burns and Combined Injury, The 2nd Department of Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
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27
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Atkins JL, Johnson KB, Pearce FJ. Cardiovascular responses to oxygen inhalation after hemorrhage in anesthetized rats: hyperoxic vasoconstriction. Am J Physiol Heart Circ Physiol 2006; 292:H776-85. [PMID: 17056674 DOI: 10.1152/ajpheart.00381.2006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxygen inhalation is recommended for the initial care of trauma victims. The improved survival seen in early hemorrhage is normally associated with an increase in blood pressure. Although clinical use of oxygen can occur late after hemorrhage, the effects of late administration have not been specifically examined. Anesthetized rats were studied using an isobaric hemorrhage model with target pressures of either 70 or 40 mmHg. At various times after hemorrhage, the feedback control of the blood pressure was stopped and the inspired gas was changed from room air to 100% oxygen. The results show that shortly after hemorrhage to 70 mmHg, oxygen inhalation results in an increase in mean arterial blood pressure of 60 +/- 3 mmHg, which is associated with a large increase in total peripheral resistance from 0.89 +/- 0.05 to 1.25 +/- 0.1 peripheral resistance units. The blood pressure response is essentially unchanged with time, and it is not altered by a 10-min exposure to N(G)-nitro-l-arginine methyl ester. At a target pressure of 40 mmHg, the initial blood pressure response to oxygen is the same, but it gradually decreases as the animal develops a lactic acidosis. We conclude that the therapeutic value of oxygen needs to be separately evaluated for late hemorrhage.
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Affiliation(s)
- James L Atkins
- Division of Military Casualty Research, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910, USA.
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28
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Warrillow S, Egi M, Bellomo R. Randomized, double-blind, placebo-controlled crossover pilot study of a potassium channel blocker in patients with septic shock. Crit Care Med 2006; 34:980-5. [PMID: 16484892 DOI: 10.1097/01.ccm.0000206114.19707.7c] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Marked potassium efflux prevents calcium entry into vascular smooth muscle cells and may be responsible for the "vasoplegia" of septic shock. Blockade of adenosine triphosphate (ATP)-sensitive potassium channels restores vascular tone in animal studies of septic shock. The effect of such potassium channel blockade has not been previously studied in humans. OBJECTIVE To test whether the administration of an ATP-sensitive potassium (K(ATP)) channel blocker restores norepinephrine responsiveness in patients with septic shock. DESIGN Randomized, double-blind, placebo-controlled crossover pilot study. SETTING Intensive care unit of a university hospital. PATIENTS Ten patients with septic shock requiring invasive hemodynamic monitoring and infusion of norepinephrine to maintain adequate mean arterial pressure. INTERVENTION In addition to standard therapy, patients were randomized to initially receive either the K(ATP) channel blocker glibenclamide (20 mg) or placebo. Then, after 24 hrs, each patient crossed over to receive the alternative therapy. MEASUREMENTS AND MAIN RESULTS After the administration of the K(ATP) channel blocker glibenclamide, median norepinephrine requirements decreased from 13 to 4 microg/min compared with a change from 19 to 7 microg/min after placebo. The two changes represented a decrease of 78.9% and 71.1% in dose, respectively (p = .57, not significant). There were also no significant changes in heart rate, mean arterial blood pressure, and lactate concentration when comparing the study drug with placebo. Glibenclamide, however, induced a significant decrease in median blood glucose concentration (5.4 [inter-quartile range, 4.5-7.0] vs. 7.0 mmol/L [5.2-9.3], p < .0001) compared with placebo and increased the need for parenteral glucose administration. CONCLUSIONS The K(ATP) channel blocker glibenclamide failed to achieve a greater reduction in norepinephrine dose than placebo in septic shock patients, although it caused a reduced glucose concentration. Our observations suggest that, in such patients, blockade of K(ATP) channels does not have a potent effect on vasomotor tone.
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29
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Atkins JL, Day BW, Handrigan MT, Zhang Z, Pamnani MB, Gorbunov NV. Brisk production of nitric oxide and associated formation ofS-nitrosothiols in early hemorrhage. J Appl Physiol (1985) 2006; 100:1267-77. [PMID: 16339342 DOI: 10.1152/japplphysiol.01059.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The results of previous inhibitor studies suggest that there is some increase in nitric oxide (NO) production from constitutive NO synthase in early hemorrhage (H), but the magnitude of NO production early after H has not been previously assessed. It is generally believed that only modest production rates are possible from the constitutively expressed NO synthases. To study this, anesthetized male Sprague-Dawley rats were subjected to 90 min of isobaric (40 mmHg) H. During this period of time, the dynamics of accumulation of NO intermediates in the arterial blood was assessed using electron paramagnetic resonance spectroscopy, chemiluminescence, fluorescence imaging, and mass spectrometry. Electron paramagnetic resonance-detectable NO adducts were also measured with spin traps in blood plasma and red blood cells. H led to an increase in the concentration of hemoglobin-NO from 0.9 ± 0.2 to 4.8 ± 0.7 μM. This accumulation was attenuated by a nonselective inhibitor of NO synthase, NG-nitro-l-argininemethyl ester (l-NAME), but not by NG-nitro-d-argininemethyl ester (d-NAME) or 1400W. Administration of l-NAME (but not 1400W or d-NAME) during H produced a short-term increase in mean arterial pressure (∼90%). In H, the level of N oxides in red blood cells increased sevenfold. S-nitrosylation of plasma proteins was revealed with “biotin switch” techniques. The results provide compelling evidence that there is brisk production of NO in early H. The results indicate that the initial compensatory response to H is more complicated than previously realized, and it involves an orchestrated balance between intense vasoconstrictor and vasodilatory components.
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Affiliation(s)
- James L Atkins
- Division of Military Casualty Research, Walter Reed Army Institute of Research, Bldg. 503, Rm. 1N80, 503 Robert Grant Ave., Silver Spring, MD 20910-7500, USA.
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30
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Voelckel WG, von Goedecke A, Fries D, Krismer AC, Wenzel V, Lindner KH. Die Behandlung des hämorrhagischen Schocks. Anaesthesist 2004; 53:1151-67. [PMID: 15597155 DOI: 10.1007/s00101-004-0771-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The future of shock treatment depends on the importance of scientific results, and the willingness of physicians to optimize, and to reconsider established treatment protocols. There are four major potentially promising approaches to advanced trauma life support. First, control of hemorrhage by administration of local hemostatic agents, and a better, target-controlled management of the coagulation system. Second, improving intravascular volume by recruiting blood from the venous vasculature by preventing mistakes during mechanical ventilation, and by employing alternative spontaneous (i.e. use of the inspiratory threshold valve) or artificial ventilation strategies. In addition, artificial oxygen carriers may improve intravascular volume and oxygen delivery. Third, pharmacologic support of physiologic, endogenous mechanisms involved in the compensation phase of shock, and blockade of pathomechanisms that are known to cause irreversible vasoplegia (arginine vasopressin and K(ATP) channel blockers for hemodynamic stabilization). Fourth, employing potentially protective strategies such as mild or moderate hypothermia. Finally, the ultimate vision of trauma resuscitation is the concept of "suspended animation" as a form of delayed resuscitation after protection of vital organ systems.
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Affiliation(s)
- W G Voelckel
- Universitätsklinik für Anästhesiologie und Allgemeine Intensivmedizin, Medizinische Universität Innsbruck.
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31
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Torres LN, Torres Filho IP, Barbee RW, Tiba MH, Ward KR, Pittman RN. Continuous peripheral resistance measurement during hemorrhagic hypotension. Am J Physiol Heart Circ Physiol 2004; 287:H2341-5. [PMID: 15256369 DOI: 10.1152/ajpheart.00179.2004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We tested the hypotheses that continuous total peripheral resistance (TPR) measurements are superior to intermittent data collection and that variables related to TPR can be used to distinguish between survivors and nonsurvivors (NS), respectively, of prolonged hemorrhagic hypotension (HH). One week after a transit-time ultrasound probe was implanted on their ascending aortas, 21 rats were subjected to 4 h of HH at 40 mmHg. Measurements were made before and up to 4 h after initiation of HH. Additional bleeding or Ringer l-lactate (RL) infusion was used to maintain HH. TPR was continuously measured online using recordings of blood flow and arterial pressure. Approximately 67% of the rats survived ≥3 h; others were considered NS. Data collected at 30-min intervals failed to detect the maximum value of TPR (TPRmax). The times to reach TPRmax were similar for survivors and NS and were strongly correlated with the bleeding end points and with the RL infusion-onset times. However, survivors showed higher TPRmax values than NS ( P < 0.005) and had a significantly longer period than NS during which TPR was above baseline level (116 ± 20 vs. 51 ± 10 min). In conclusion, 1) the transit-time ultrasound technique at high sampling rate allowed continuous and accurate real-time monitoring of TPR, 2) the bleeding end point and RL infusion-onset times may be used as surrogates of the time to TPRmax, 3) TPRmax of survivors and NS could be detected only using a continuous TPR measurement, and 4) differences between survivors and NS could be revealed by the continuous TPR curve.
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Affiliation(s)
- Luciana N Torres
- Dept. Physiology,, Virginia Commonwealth University Reanimation Engineering Shock Center, Virginia Commonwealth University Health System, Richmond, Virginia 23298-0401, USA.
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32
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Kan W, Zhao KS, Jiang Y, Yan W, Huang Q, Wang J, Qin Q, Huang X, Wang S. Lung, spleen, and kidney are the major places for inducible nitric oxide synthase expression in endotoxic shock: role of p38 mitogen-activated protein kinase in signal transduction of inducible nitric oxide synthase expression. Shock 2004; 21:281-7. [PMID: 14770043 DOI: 10.1097/01.shk.0000113314.37747.55] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Bacterial lipopolysaccharide (LPS) is known to induce endotoxic shock with inducible nitric oxide (NO) synthase (iNOS) expression and NO production. However, the major place for NO production in shock remains unclear. Although there is some literature about p38 mitogen-activated protein kinase (MAPK) in regulating LPS-induced iNOS expression, the results are contradictory. To interpret the precise cell mechanism and the role of p38 MAPK in the expression of iNOS during endotoxic shock, we carried out the following investigations. A severe endotoxic shock model was reproduced in mice 6 h after LPS injection. The plasma NO level was increased in a dose- and time-dependent manner after LPS stimulation and was suppressed by administration of SB203580 [4-(4-fluorophenyl)-2-4-methylsulfonylphenyl-5-(4-pyridyl) imidazole], a highly specific inhibitor of p38 MAPK. The iNOS expression was increased in many organs, including heart, liver, spleen, lung, gut, and kidney in endotoxic shock. Among them, the highest expression of iNOS mRNA and protein was in the lung, moderate expression was in the spleen and kidney, and the lowest expression was in the heart, gut, and liver. The level of expression in lung was 5.5 times that of iNOS mRNA and was 3.1 times that of iNOS protein than in heart, and 1.6 and 1.8 times that of iNOS mRNA and 1.7 and 1.4 times that of iNOS protein than in spleen and kidney, respectively. The p38 MAPK activity increased after LPS injection, and SB203580 markedly reduced LPS-induced expressions of iNOS protein and mRNA in the lung. The results indicates that lung, spleen, and kidney are the major places for iNOS expression in endotoxic shock and are important therapeutic target organs for attenuating NO production in shock treatment.
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Affiliation(s)
- Wenhong Kan
- Department of Pathophysiology, The First Military Medical University, Guangzhou, China
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33
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Asfar P, Iványi Z, Bracht H, Hauser B, Pittner A, Vassilev D, Nalos M, Leverve XM, Brückner UB, Radermacher P, Fröba G. HMR1402, a potassium ATP channel blocker during hyperdynamic porcine endotoxemia: effects on hepato-splanchnic oxygen exchange and metabolism. Intensive Care Med 2004; 30:957-64. [PMID: 15045166 DOI: 10.1007/s00134-004-2258-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2003] [Accepted: 02/25/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To assess the effects of the potassium ATP (KATP) channel blocker HMR1402 (HMR) on systemic and hepato-splanchnic hemodynamics, oxygen exchange and metabolism during hyperdynamic porcine endotoxemia. DESIGN Prospective, randomized, controlled study with repeated measures. SETTING. Animal laboratory. SUBJECTS Eighteen pigs allocated to receive endotoxin alone (control group, CON, n=10) or endotoxin and HMR (6 mg/kg h(-1), n=8). INTERVENTIONS Anesthetized, mechanically ventilated, and instrumented pigs receiving continuous i.v. endotoxin were resuscitated with hetastarch to maintain mean arterial pressure (MAP) >60 mmHg. Twelve hours after starting the endotoxin infusion, they received HMR or its vehicle for another 12 h. RESULTS HMR transiently increased MAP by about 15 mmHg, but this effect was only present during the first 1 h of infusion. The HMR decreased cardiac output due to a fall in heart rate, and thereby reduced liver blood flow. While liver O(2) delivery and uptake remained unchanged, HMR induced hyperlactatemia [from 1.5 (1.1; 2.0), 1.4 (1.2; 1.8), and 1.2 (0.8; 2.0) to 3.1 (1.4; 3.2), 3.2 (1.6; 6.5), and 3.0 (1.0; 5.5) mmol/l in the arterial, portal and hepatic venous samples, respectively] and further increased arterial [from 8 (3; 13) to 23 (11; 57); p<0.05], portal [from 9 (4; 14) to 23 (14; 39); p<0.05] and hepatic vein [from 7 (0; 15) to 30 (8; 174), p<0.05] lactate/pyruvate ratios indicating impaired cytosolic redox state. CONCLUSION The short-term beneficial hemodynamic effects of KATP channel blockers have to be weighted with the detrimental effect on mitochondrial respiration.
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Affiliation(s)
- Pierre Asfar
- Sektion Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Parkstrasse 11, 89073 Ulm, Germany
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Pan BX, Zhao GL, Huang XL, Jin JQ, Zhao KS. Peroxynitrite induces arteriolar smooth muscle cells membrane hyperpolarization with arteriolar hyporeactivity in rats. Life Sci 2004; 74:1199-210. [PMID: 14697404 DOI: 10.1016/j.lfs.2003.07.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Peroxynitrite (ONOO-) has been recently known to act as a potent cytotoxin during pathogenesis of various diseases. This study aimed to investigate the possible effect of ONOO- on the cremaster muscle arteriolar reactivity in response to noradrenaline and subsequently determined whether membrane hyperpolarization and potassium channel activation were involved in ONOO(-)-induced alteration of arteriolar reactivity. The results demonstrated that 1) ONOO- could decrease arteriolar reactivity in a time- and concentration-dependent manner with no significant alteration of arteriolar diameter; 2) Superfusion with 20 microM ONOO- over 40 minutes showed slight but not significant influence on the resting potential (Em) of arteriolar smooth muscle cells (ASMCs). However, ASMCs subjected to 50 or 100 microM ONOO- administration were significantly hyperpolarized. As control, treatment with 50 microM decomposed ONOO- or Kreb's solution had little effect on the Em of ASMCs; 3) ONOO(-)-induced arteriolar hyporeactivity could be greatly reversed by co-administration of KCl and partially by TEA. The above results indicated that membrane hyperpolarization and potassium channel activation were preferentially responsible for the reduction of cremaster muscle arteriolar reactivity after exposure to ONOO-.
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Affiliation(s)
- Bing-Xing Pan
- Key Lab for Shock and Microcirculation of PLA, Department of Pathophysiology, The First Military Medical University, Guangzhou 510515, PR China
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