Lecture 9 AI generated Flashcards
Describe ischemic heart disease.
Ischemic heart disease, also known as cardiac ischemia, is a condition where there is insufficient blood flow to the heart tissue, leading to tissue injury due to ATP depletion. The duration of ischemia determines the severity of the damage, with longer durations resulting in more severe consequences.
What is reperfusion in the context of ischemic heart disease?
Reperfusion is the restoration of blood flow to the affected tissue after a period of ischemia. While reperfusion is necessary to limit damage, it can also contribute significantly to tissue injury.
Define oxidative stress in the context of ischemia/reperfusion.
Oxidative stress refers to an imbalance between the production of reactive oxygen species (ROS) and the ability of the body to detoxify them. In the case of ischemia/reperfusion, excessive ROS generation can lead to damage in the heart tissue.
How can people with ischemia be treated with cardiac reperfusion?
People with ischemia can be treated with cardiac reperfusion through procedures like percutaneous coronary intervention (PCI), which aims to restore blood flow to the heart tissue.
Describe the role of reactive oxygen species (ROS) in ischemia/reperfusion.
ROS, which are reactive oxygen species or radicals of oxygen, have an important physiological signaling function, but excessive ROS production can lead to oxidative stress and damage in the heart tissue during ischemia/reperfusion.
What are some of the consequences of exposure to ROS in animals during ischemia/reperfusion?
Exposure to ROS in animals during ischemia/reperfusion can lead to deletion of superoxide dismutase (SOD), overexpression of ROS generating enzymes, and the presence of ROS footprints like lipid peroxidation, oxidized glutathione (GSSG), and fluorescent probes.
Describe the role of mitochondria in producing reactive oxygen species (ROS).
Mitochondria are a significant source of ROS, which can lead to damage to DNA, lipids, and membranes.
What is the impact of ROS on the heart during ischemia reperfusion?
ROS can cause oxidative damage, leading to an increase in infarct size. Counteracting this process, such as with vitamin C treatment, can reduce infarct size.
Define oxidative phosphorylation and its relation to ROS production.
Oxidative phosphorylation is a process in the mitochondria that can lead to the production of ROS, which can be mitigated by enzymes like ETC and NNT.
How does the type of fuel used by the heart change in diseased conditions?
In diseased conditions, the heart switches from primarily using fat for energy to relying more on sugar as a fuel source.
Describe the therapeutic implications of reducing ROS damage during acute myocardial infarction.
Reducing ROS damage, such as through vitamin C treatment, can potentially decrease infarct size by up to 50%.
What are some factors that can influence the effectiveness of ROS-targeted therapies?
Factors such as dosage, diet, administration method (intravenous/oral), and individual variations in ROS production can impact the effectiveness of ROS-targeted therapies.
Describe the role of HIF-1 in response to ischemia/hypoxia.
HIF-1 is a transcription factor that regulates the response to low oxygen levels. It promotes survival, restores oxygen delivery, and regulates processes like metabolic adaptation, cell survival, redox homeostasis, and angiogenesis.
What are the key roles of HIF-1 in cellular processes?
The key roles of HIF-1 include metabolic adaptation (especially glucose metabolism), cell survival, redox homeostasis, and angiogenesis.
How does HIF-1 mediate metabolic adaptations under hypoxic conditions?
HIF-1 promotes the use of carbohydrates as a fuel source instead of fat in the heart during ischemia, helping in reducing damage and the risk of a myocardial infarction.
