Hypoxia from ischemia

CAl hippocampal neurons are preferentially susceptible to hypoxia and ischemia. In CAl, CA3, and dentate gyrus neurons dissected from fresh rat hippocampal slices, CN specifically enhanced release of acid metabolic products from CAl cells but had little effect on the other cells. " By contrast, kainate, which has CA3-specific effects, increased acid metabolite release only in CA3 neurons. " Actions of CN appear to be metabolic in nature and not aU neuronal cell types are equally affected. 

From earlier times when it has first been established that ischemia and hypoxia are the potential causes of coronary heart disease and myocardial infraction [50,51], antioxidants... 

Ri-measured PO2. Global Ischemia showed complete hypoxia for both groups with or without KCI arrest. Error bars represent one standard deviation of measurements from multiple hearts (data adapted from Ph.D. thesis of HImu Shukla, UT Southwestern 1994) [405]. 

Many factors can precipitate or exacerbate arrhythmias ischemia, hypoxia, acidosis or alkalosis, electrolyte abnormalities, excessive catecholamine exposure, autonomic influences, drug toxicity (eg, digitalis or antiarrhythmic drugs), overstretching of cardiac fibers, and the presence of scarred or otherwise diseased tissue. However, all arrhythmias result from (1) disturbances in impulse formation, (2) disturbances in impulse conduction, or (3) both. 

Eliminate the cause. Precipitating factors must be recognized and eliminated if possible. These include not only abnormalities of internal homeostasis, such as hypoxia or electrolyte abnormalities (especially hypokalemia or hypomagnesemia), but also drug therapy and underlying disease states such as hyperthyroidism or cardiac disease. It is important to separate this abnormal substrate from triggering factors, such as myocardial ischemia or acute cardiac dilation, which may be treatable and reversible. 

Hypoxia is a deficiency of oxygen needed to maintain cellular homeostasis. It may be caused by a reduction in blood supply, namely ischemia, decreased cardiopulmonary function, and diminished oxygen-carrying capacity of the blood. Subsequent oxygen deficiency in tissues leads to depressed aerobic metabolism and, thus, insufficient ATP synthesis. Reductions in blood flow also exacerbate oxygen deprivation by impairing delivery of nutrients, such as glucose, and the removal of metabolic wastes, such as C02, from affected cells. 

There is major evidence regarding the role of A (AR in neurodegenerative phenomena from in vivo and in vitro studies in hypoxia/ischemia models. 

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