ability in oxygen delivery and diffusion of the blood vessels and increased oxygen consumption in the rapidly proliferating cancer cells both contribute to reduced oxygen availability in the solid tumors, a major signature of the tumor microenvironment [1]. The oxygen concentration is dynamically changed within the tumor, and thus tumor cells are frequently subjected to acute or chronic hypoxia...

To investigate the influence of chronic hypoxia and anoxia on cell survival after low- and high-LET radiation, CHO-K1 cells were kept for 24 h under chronic hypoxia (94.5% N2; 5% CO2; 0.5% O2) or chronic anoxia (95% N2; 5% CO2). Irradiation was performed using 250 kVp X-rays or carbon ions with a dose average LET of 100 keV/μm either directly under the chronic oxygenation states, or at differen...

Sterni, L. M., O. S. Bamford, M. J. Wasicko, and J. L. Carroll. Chronic hypoxia abolished the postnatal increase in carotid body type I cell sensitivity to hypoxia. Am. J. Physiol. 277 (Lung Cell. Mol. Physiol. 21): L645–L652, 1999.—The O2 sensitivity of carotid chemoreceptor type I cells is low just after birth and increases with postnatal age. Chronic hypoxia during postnatal maturation blunt...

Buchholz, John, and Sue P. Duckles. Chronic hypoxia alters prejunctional a2-receptor function in vascular adrenergic nerves of adult and fetal sheep. Am J Physiol Regulatory Integrative Comp Physiol 281: R926–R934, 2001.—The impact of development and chronic high-altitude hypoxia on the function of prejunctional a2-adrenoceptors was studied by measuring norepinephrine release in vitro from feta...

Chronic anemia-induced hypoxia triggers regulatory pathways that mediate long-term adaptive cardiac and cerebral changes, particularly at the transcriptional level. These adaptative mechanisms include a regulated cerebral blood flow and cardiac output, angiogenesis and cytoprotection triggered by hypoxia-inducible factor 1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), neuronal nitr...

In anesthetized rats, increases in phrenic nerve amplitude and frequency during brief periods of hypoxia are followed by a reduction in phrenic nerve burst frequency [posthypoxia frequency decline (PHFD)]. We investigated the effects of chronic exposure to hypoxia on PHFD and on peripheral and central O2-sensing mechanisms. In Inactin-anesthetized (100 mg/kg) Sprague-Dawley rats, phrenic nerve ...

Introduction: Ghrelin is an endogenous peptide that has diverse functions in the body. One of the newly recognized roles of this peptide is its antiapoptotic effect. However, this function has not been investigated in normobaric hypoxia- induced apoptosis in body organs. This study will examine the effect of ghrelin treatment on Bax-Bcl-2 gene expression in the kidney of chronic hypoxic rats. ...

Our study addresses selected parameters of rat erythrocyte ion transport (Na(+)-K(+) pump, Na(+)-K(+)-2Cl- cotransport, and passive cation fluxes) after acute or chronic hypoxia exposure. We did not find any significant change of ion transport after acute hypoxia. However, chronic hypoxia could modify ion transport because the affinity of Na(+)-K(+) pump for intracellular Na(+) seems to be decr...

Fletcher, Eugene C. Invited Review: Physiological consequences of intermittent hypoxia: systemic blood pressure. J Appl Physiol 90: 1600–1605, 2001.—One of the major manifestations of obstructive sleep apnea is profound and repeated hypoxia during sleep. Acute hypoxia leads to stimulation of the peripheral chemoreceptors, which in turn increases sympathetic outflow, acutely increasing blood pre...