Oxygen-Sensing Mechanisms

A third alternative has been the use of human tumor eell lines related to PNEC/NEB, namely, small-ceU lung carcinoma (SCLC). Although more than 60 SCLC cell lines have been described and partially characterized (68,69), relatively few are being used as models for PNEC/NEB cell function. More detailed analysis of SCLC cell lines revealed that most retained multiple phenotypie and biochemical 

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Ionic Currents and 02-Sensing Properties of NEB Ceiis in Fetai/Neonatai Lungs 

Following a depolarizing pulse to 30 mV from a holding potential of —60m NEB cells in neonatal rabbit lung slices generated an outward current that was blocked ( 50%) by 20 mM tetraethylammonium (TEA) or 2mM 4-aminopyridine (4-AP). The activation threshold of this K+ current was around —45 mV The on- 

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Goldberg, M.A., and Schneider, TJ. 1994. Similarities between the oxygen-sensing mechanisms regulating the expression of vascular endothelial growth factor and erythropoietin. J. Biol. Chem. 269 4355 1361. 

Land, S.C., and P.W. Hochachka (1995). A heme-protein based oxygen sensing mechanism controls the expression and suppression of multiple proteins in anoxia tolerant turtle hepatocytes. Proc. Natl. Acad. Sci. USA 92 7505-7509. 

Maxwell, P.H., C.W. Pugh, and P.J. Ratcliffe (1993). Inducible operation of the erythropoitin 3 enhancer in multiple cell lines Evidence for a widespread oxygen-sensing mechanism. Proc. Natl. Acad. Sci. USA 90 2423-2427. 

Wolin, M.S., Ahmad, M., Gupte, S.A. (2005). Oxidant and redox signaling in vascular oxygen sensing mechanisms basic concepts, current controversies, and potential importance of cytosolic NADPH. Am. J. Physiol. Lung Cell Mol. Physiol. 289 L159-73. 

Haddad JJ. 2002. Oxygen-sensing mechanisms and the regulation of redox-responsive transcription factors in development and pathophysiology. Respir Res 3 26. 

Two oxygen-sensing mechanisms help cells respond to oxygen deprivation one mechanism activates transcription of hypoxia-induced factor 1 (HIF-1), and the other promotes stabilization of HIF-1 by inhibiting its proteasomal degradation. 

Pt-doped Ti02 sensors showed low operation temperature (350-800°C), improved gas sensitivity and short response time (<0.1 s) [300, 301]. The oxygen-sensing mechanism is a combination of F JTi02 interfaces in a Schottky-barrier mechanism and an oxygen vacancy bulk effect mechanism [302]. It has been demonstrated that at high temperatures. 

Zhou X. H., Sprensen O. T., Cao Q. X., and Xu Y. L., Electrical conduction and oxygen sensing mechanism of Mg-doped SrTiOj thick film sensors. Sens. Actuators B, 65, 52-54, 2000. 

Rychkov G, Adams M, McMdlen I, Roberts M. Oxygen-sensing mechanisms are present in the chromaffin cells of the sheep adrenal medulla before birth. J Physiol (Lond) 1998 509(Pt 3) 887-893. 

Figure 3 Two-cytochrome model hypothesizing the oxygen-sensing mechanism in rat carotid body tissue.

Reeve HL, Michelakis E, Nelson DP, Weir EK, Archer SL. Alterations in a redox oxygen sensing mechanism in chronic hypoxia. J Appl Physiol 2001 90 2249-2256. 

Wolin MS, Burke-Wolin TM, Mohazzab-H KM. Roles for NAD(P)H oxidases and reactive oxygen species in vascular oxygen sensing mechanisms. Respir Physiol 1999 115 229-238. 

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