Severe hypoxia is a common cause of major brain, heart, and kidney injury in adults, children, and newborns. However, mild hypoxia can be protective against later, more severe hypoxia exposure via "hypoxic preconditioning," a phenomenon that is not yet fully understood. Accordingly, we have established and optimized an embryonic zebrafish model to study hypoxic preconditioning. Using a function...

Vasomotor response of the coronary artery depends on both endothelial and smooth muscle cells. Response is altered by hypoxia-reoxygenation-induced damages. Hypoxic preconditioning and pharmacological preconditioning as well can prevent these alterations. We compared the effectiveness of both types of preconditioning against hypoxia-reoxygenation-induced changes in vasomotor response of the iso...

Perinatal insults and subsequent neuroinflammation are the major mechanisms of neonatal brain injury, but there have been only scarce reports on the associations between hypoxic preconditioning and glial activation. Here we use neonatal hypoxia-ischemia brain injury model in 7-day-old rats and in vitro hypoxia model with primary mixed glial culture and the BV-2 microglial cell line to assess th...

BACKGROUND Exposure to hypoxia and isoflurane (Iso) before hypoxia-ischemia has been found to be neuroprotective in neonatal rats. We investigated the long-term effects of delayed preconditioning with Iso, hypoxia, or room air on motor and cognitive function in mice that had 65 min of hypoxia-ischemia on postnatal day 10. METHODS Nine-day-old C57x129T2 F1 mice received either 1.8% Iso, hypoxi...

Various in vitro preconditioning strategies have been implemented to increase the regenerative capacity of MSCs. Among them are modulation culture atmosphere (hypoxia or anoxia), three-dimensional (3D), addition trophic factors (in form growth factors, cytokines hormones), lipopolysaccharides, and pharmacological agents. Preconditioning mesenchymal stem cells by culturing a hypoxic environment,...

MicroRNAs are posttranscriptional gene regulators that are differentially expressed during various diseases and have been implicated in the underlying pathogenesis. We report here that miR-199a is acutely downregulated in cardiac myocytes on a decline in oxygen tension. This reduction is required for the rapid upregulation of its target, hypoxia-inducible factor (Hif)-1alpha. Replenishing miR-1...

All animals require molecular oxygen for aerobic energy production, and oxygen availability has played a particularly important role in the evolution of aquatic animals. This study investigates how previous exposure to hypoxia (preconditioning) primes protective transcriptional responses in a hypoxia-tolerant vertebrate species, the epaulette shark (Hemiscyllium ocellatum). The epaulette shark ...

A short period of hypoxia reduces the cytotoxicity produced by a subsequent prolonged hypoxia in isolated hepatocytes. This phenomenon, termed hypoxic preconditioning, is mediated by the activation of adenosine A2A-receptor and is associated with the attenuation of cellular acidosis and Na+ overload normally occurring during hypoxia. Bafilomycin, an inhibitor of the vacuolar H+/ATPase, reverts ...

Brief episodes of cerebral hypoxia-ischemia cause transient ischemic tolerance to subsequent ischemic events that are otherwise lethal. This study was conducted to evaluate the protective effect of hypoxic preconditioning on hypoxic-ischemic injury in the neonatal rat and the persistence of a protective window after hypoxic preconditioning. The rats were preconditioned with hypoxia (8% oxygen, ...

Zhang, Hong Yan, Bradley C McPherson, Huiping Liu, Timir S Baman, Peter Rock, and Zhenhai Yao. H2O2 opens mitochondrial KATP channels and inhibits GABA receptors via protein kinase Cin cardiomyocytes. Am J Physiol Heart Circ Physiol 282: H1395–H1403, 2002; 10.1152/ajpheart.00683.2001.—Oxygen radicals and protein kinase C (PKC) mediate ischemic preconditioning. Using a cultured chick embryonic c...