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Coronary Vascular Endothelium, Preconditioning and Arrhythmogenesis
Published in Malcolm J. Lewis, Ajay M. Shah, Endothelial Modulation of Cardiac Function, 2020
There is abundant evidence that the endothelium plays a significant role in modulating coronary vasomotor tone through the synthesis and metabolism of various vasoactive substances (Vane and Botting, 1994; Bassenge, 1995; Gryglewski et al., 1995). Rather more recently, it has been recognised that endocardial endothelial and coronary vascular endothelial cells communicate with cardiac myocytes to modulate contractility through the release of various endothelium-derived substances which include nitric oxide and endothelin, a subject extensively reviewed elsewhere in this volume. In this chapter we summarise the evidence that endothelium-derived substances also modify, in a protective fashion, the life-threatening ventricular arrhythmias that arise during a period of myocardial ischaemia and reperfusion. In particular, we summarise the evidence that the pronounced antiarrhythmic effects of ischaemic preconditioning are due, in part, to the elaboration of such substances. In this context we define ischaemic preconditioning as “the increased tolerance of the myocardium to ischaemic injury after it has been ‘primed’ by much shorter periods of ischaemia”. These can be induced, for example, by partial or complete coronary artery occlusion or by cardiac pacing.
Hormesis: Using Preconditioning to Build Biological Shields—A Novel Approach for Enhancing Resilience to Toxic Agents, Traumatic Illness/Injury, and Age-Related Degenerative Diseases
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
The concept of preconditioning is important, since it provides a means by which biological systems can increase their resilience and resist harmful effects of a subsequent, more massive and damaging stress or event. It is via the hormesis-based preconditioning process that biological systems can upregulate adaptive processes and build biological shields that provide protection against subsequent, more powerful stresses. The fundamental feature of preconditioning against a subsequent damaging stress is that the dose of the preconditioning agent needs to be high enough to have a biological stimulatory/initiating function yet at a sub-threshold level with respect to causing harm or injury.
Preclinical Models
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Irene Cuadrado, Jesús Egido, Jose Luis Zamorano, Carlos Zaragoza
The method has been further modified to analyze ischemic preconditioning of the heart. In this method, the left coronary artery is repeatedly occluded to subject the heart to several rounds of brief ischemia and reperfusion, followed by permanent occlusion. This approach has identified several ischemia-induced genes that confer tolerance to a subsequent ischemic event (Xuan et al. 2007).
Preparing the spinal cord – priming or preconditioning? A systematic review of experimental studies
Published in Scandinavian Cardiovascular Journal, 2023
Johanna Herajärvi, Tatu Juvonen
Despite the vast body of literature available on the topic of preconditioning, no clear understanding of its mechanisms and efficacy has been gained. In the spinal cord, the early studies on heat shock proteins (HSP) reported mainly positive results [48,49,68,69,73]. Heat shock proteins are chaperons taking part in the process of protein folding. The cellular distribution of HSPs was evaluated by Matsumoto et al. their presence in the nucleus was detected in conditioned animals suggesting participation in the mechanism of preconditioning [49]. In contrary, Selimoglu et al. have reported increased HSP expression in both preconditioned and control animals [74]. In addition, Kyrou et al. found no relationship between HSPs and β-catenin which is a protein maintaining tissue architecture and cell polarity in adherent junctions, and thus HSP lacks its regulatory role on β-catenin during early ischemic preconditioning [69]. They concluded that β-catenin showed increased levels, as well as translocation between cytoplasm and nucleus suggesting its role in Akt regulation resulting in antiapoptotic and cytoprotective effects [69].
The effect of preconditioning agents on cardiotoxicity and neurotoxicity of carbon monoxide poisoning in animal studies: a systematic review
Published in Drug and Chemical Toxicology, 2023
Hamed Baharara, Hanieh Ghasemi, Sara Samadi, Bahar Roohshad, Vahid Jomehzadeh, Khosrow Ravankhah Moghaddam, Amir Hooshang Mohammadpour, Omid Arasteh
Nonetheless, our study has some limitations. The first one is that we do not have access to some full texts and it may affect our judgment. Secondly, each precondition at maximum rate, had four related articles and they evaluated different markers and different duration of injections to assess acute or late phases of poisoning. However, doses that administered are different and it is another limitation in this study. We tried to classify studies to reduce this limitation. Although different durations of injection were considered as our limitation, we categorized studies into acute and late phases. Due to the lack of data and heterogenicity between studies, we could not explain and deduce results comprehensively. Finally, most of the studies were unclear in risk of bias assessment, in which they had selection bias (sequence generation and allocation concealment), performance bias, detection bias, reporting bias, and other source of bias. This variety of sources of bias and existing a few studies on each preconditioning could effect on deduction of the results.
The pros and cons of motor, memory, and emotion-related behavioral tests in the mouse traumatic brain injury model
Published in Neurological Research, 2022
Ruoyu Zhang, Junming Wang, Leo Huang, Tom J. Wang, Yinrou Huang, Zefu Li, Jinxin He, Chen Sun, Jing Wang, Xuemei Chen, Jian Wang
Preconditioning is a manifestation of hormesis which is defined as a noxious stimulus below the cell injury threshold that can lead to cellular protection from subsequent severe insult [152,153]. Neuroprotection conferred by preconditioning has been demonstrated in several preclinical TBI studies with promising results [154]. The behavioral tests can be used as parameters to reflect the functional outcomes of hormesis in these experimental conditions. As one of the important preconditioning signals, sublethal doses of N-methyl-d-aspartate (NMDA) can induce endogenous protective mechanisms, which improves functional recovery after TBI. In the study by Costa et al., the NMDA preconditioning before TBI led to improvement in sensory-motor activity, coordination, and balance without distortion of gait [155]. Moojen et al. showed that the mice under NMDA preconditioning were protected against TBI-induced cognitive deficits evaluated by the novel object recognition test [156]. Additionally, endotoxin lipopolysaccharide preconditioning attenuated TBI-induced motor deficits assessed by NSS and the beam walking test [157]. Therefore, evaluation of behavioral correlates of histologically measured gray and white matter injury can help elucidate endogenous protective and repair mechanisms of preconditioning signals.