Arabidopsis has inducible responses for tolerance of O2 deficiency. Plants previously exposed to 5% O2 were more tolerant than the controls to hypoxic stress (0.1% O2 for 48 h) in both roots and shoots, but hypoxic acclimation did not improve tolerance to anoxia (0% O2). The acclimation of shoots was not dependent on the roots: increased shoot tolerance was observed when the roots of the plants...

Thioredoxin is a small redox-regulating protein, which plays crucial roles in maintaining cellular redox homeostasis and cell survival and is highly expressed in many cancers. The tumor environment is usually under either oxidative or hypoxic stress and both stresses are known up-regulators of thioredoxin expression. These environments exist in tumors because their abnormal vascular networks re...

The hypoxic microenvironment contributes to embryonic development and tumor progression through stabilization of the potent transcriptional factor HIFalpha. In normoxia, the tumor suppressor protein VHL acts as an E3 ubiquitin ligase to target HIFalpha for proteolytic destruction. Increasing evidence shows that VHL is a multifunctional adaptor involved in inhibition of HIFalpha-dependent and in...

It is now known that there are several classes of haemoglobins in plants. A specialized class of haemoglobins, symbiotic haemoglobins, were discovered 62 years ago and are found only in nodules of plants capable of symbiotic nitrogen fixation. Plant haemoglobins, with properties distinct from symbiotic haemoglobins were discovered 18 years ago and are now believed to exist throughout the plant ...

Chronic hypoxia causes pulmonary hypertension and right ventricular hypertrophy associated with pulmonary vascular remodeling. Because hypoxia might promote generation of oxidative stress in vivo, we hypothesized that oxidative stress may play a role in the hypoxia-induced cardiopulmonary changes and examined the effect of treatment with the antioxidant N-acetylcysteine (NAC) in rats. NAC reduc...

Hypoxia is an established factor of neurodegeneration. Nowadays, attention is directed at understanding how alterations in the expression of stress-related signaling proteins contribute to age dependent neuronal vulnerability to injury. The purpose of this study was to investigate how Hif-1α, a major neuroprotective factor, and JNK signaling, a key pathway in neurodegeneration, relate to hypoxi...

Although the nature of renal dysfunction following the use of iodinated radiological contrast agents has long been a matter of dispute, tubular hypoxic injury does play a central role as indicated by both clinical observations and experimental animal models. Indeed, radiocontrast agents induce renal parenchymal hypoxic stress resulting from a critically low ambient pO2 that develops particularl...

In this study, we investigated the way in which fetal insulin secretion is influenced by interrelated changes in blood glucose and sympathoadrenal activity. Experiments were conducted in late gestation sheep fetuses prepared with chronic peripheral and adrenal catheters. The fetus mounted a brisk insulin response to hyperglycemia but with only a minimal change in the glucose-to-insulin ratio, i...

Receptor tyrosine kinases (RTKs) are high-affinity cell surface receptors for many polypeptide growth factors, cytokines and hormones. RTKs are not only key regulators of normal cellular processes, but are also involved in the progression of many types of tumors, and responses to various biotic and abiotic stresses. Catfish is a primary aquaculture species in the United States, while its indust...

The physiological mechanisms that might be involved in an association between heat stress and sudden infant death syndrome (SIDS) are obscure. We tested the hypothesis that a combination of acute hypoxia and elevated body temperature (T(B)) might prevent autoresuscitation from hypoxic apnea (AR). We exposed 21-day-old mice (total = 216) to hyperthermia (40.5-43.5 degrees C), hypoxia, or a combi...