View clinical trials related to Ischemia Reperfusion Injury.
Filter by:The chemokine CXCL8 plays a key role in the recruitment and activation of polymorphonuclear neutrophils in post-ischemia reperfusion injury after solid organ transplantation. Reparixin is a novel, specific inhibitor of CXCL8. This study is configured to explore the safety and efficacy of reparixin in preventing the delayed graft function (DGF) after kidney transplantation.
The chemokine CXCL8 plays a key role in the recruitment and activation of polymorphonuclear neutrophils in post-ischemia reperfusion injury after solid organ transplantation. Repertaxin is a novel, specific inhibitor of CXCL8. This study is configured to explore the safety and efficacy of repertaxin in preventing the primary graft dysfunction (PGD) after lung transplantation.
The most powerful protective mechanism against ischemia-reperfusion injury other than rapid reperfusion is ischemic preconditioning. Ischemic preconditioning is defined as the development of tolerance to ischemia-reperfusion injury by a previous short bout of ischemia resulting in a marked reduction in infarct size. This mechanism can be mimicked by several pharmacological substances such as adenosine and morphine. We, the researchers at Radboud University Nijmegen Medical Centre, have recently developed a method in which we can detect ischemia-reperfusion injury in the human forearm by using Annexin A5 scintigraphy (Rongen et al). With this method we will determine whether opioid receptors are involved in ischemic preconditioning. We expect to find that morphine can mimic ischemic preconditioning and that acute ischemic preconditioning can be blocked with the opioid receptor antagonist naloxon. This study will increase our knowledge about the mechanism of ischemic preconditioning and may also provide leads to exploit this endogenous protective mechanism in a clinical setting.
Ischaemic preconditioning (IP) describes the phenomenon that brief periods of ischaemia render the (myocardial) muscle more resistant to a subsequent more prolonged period of ischaemia and reperfusion. Animal studies have provided evidence that adenosine receptor stimulation is an important mediator of IP. As caffeine is an effective adenosine receptor antagonist already at concentrations reached after regular coffee consumption, we aimed to assess whether caffeine impairs IP in humans in vivo. We used a novel and well-validated model to study IP in humans: 99m-Tc-annexin A5 scintigraphy in forearm skeletal muscle. 24 healthy volunteers were randomly assigned to either caffeine (4 mg/kg/iv in 10 minutes) or saline before a protocol for IP.
Ischemic preconditioning is defined as the development of tolerance to ischemia-reperfusion injury by a previous short bout of ischemia resulting in a marked reduction in infarct size. This mechanism can be mimicked by several pharmacological substances such as acetylcholine and adenosine. To detect ischemia-reperfusion injury in humans in vivo Kharbanda et al. developed a method in which endothelial dysfunction represents the effects of ischemic preconditioning. This method, however, uses acetylcholine to measure endothelial function before and after forearm ischemia. We, the investigators at Radboud University, hypothesize that the use of acetylcholine in this model reduces ischemia-reperfusion injury. Therefore, we will compare this protocol with a protocol in which endothelial function is only measured after ischemia. We expect an increase in ischemia-reperfusion injury when endothelial function is only measured after the forearm ischemia. After determining the optimal method to measure ischemia-reperfusion injury of the vascular endothelium we will determine the effect of acute and chronic caffeine, an adenosine receptor antagonist, on ischemic preconditioning. With this study we expect to find that adenosine mimics ischemic preconditioning of the vascular endothelium. Moreover, we expect to find that acute caffeine intake reduces ischemia-reperfusion injury whereas chronic caffeine intake does not. This study will increase our knowledge about the mechanism of ischemic preconditioning and may also provide leads to exploit this endogenous protective mechanism in a clinical setting.
In this proof-of-concept study, forearm vulnerability to ischemic exercise is studied in patients with type 1 diabetes mellitus with and without prior ischemic preconditioning (short period of ischemia that protects against subsequent ischemic exercise). Annexin A5 scintigraphy is used to quantify subtle signs of mild and reversible forearm injury that results from ischemic exercise. The following hypotheses are tested: 1. Patients with type 1 diabetes are not more vulnerable to ischemic injury as compared with previously studied healthy volunteers. 2. Ischemic preconidtioning is still present in patients with type 1 diabetes. Depending on the validity of hypothesis 2, the effect of short pharmacological interventions are studied on vulnerability to forearm ischemia/reperfusion injury in the absence or presence of local forearm ischemic preconditioning.
The purpose of this study is to evaluate the effects of inhaled nitric oxide on both short-term physiology as well as on the development of ischemia-reperfusion lung injury (IRLI) in the immediate post transplant period. The specific hypothesis is that inhaled NO post lung transplantation will improve gas exchange/hemodynamic and thus reduce the development of post transplant IRLI.