Hypoxia comparative effectiveness

D. V. Fitzpatrick, M. Karmazyn, Comparative effects of calcium channel blocking agents and varying extracellular calcium concentration on hypoxia/reoxygenation and ischemia/reperfusion-induced cardiac injury, J Pharmacol Exp Ther 28, 761-768 (1984). 

As the AO with a direct nonspecific mechanism of action we have chosen Hypoxene - sodium poly(2,5-dihydroxiphenyl)-4-thiosulfonate. Besides a direct AO effect as a scavenger of free radicals it exerts an anti-hypoxic effect shunting I and II complexes of mitochondrial respiratory chain, which are inhibited as a consequence of hypoxia (Eropkin et al., 2007). Hypoxene was introduced into cell incubation media before illumination and left during cells further incubation. Hypoxene in the concentration of 40pg/ml, comparable to doses applied in vivo, completely blocked C60-induced phototoxicity (Table 7.3). Cellular viability has completely recovered to control level, which is a convincing evidence of free radical nature of cellular damage in photodynamic effect of fullerene. 

Figure 5.1. The interplay between time and adaptational options occurs in human as well as in animal evolution of physiological systems. The acute and acclimation effects on human hypoxia response physiology can be readily evaluated. However, adaptations requiring generations of time of course cannot be studied by direct manipulations in humans. All workers in this area therefore rely upon comparing human lineages adapted to hypobaric hypoxia in different regions of the world and for different time periods. Two such groups that have extensively studied in this manner are Quechuas and Aymaras from the Andes, and Sherpas and Tibetans from the Himalayas. See chapter 1 for further discussion of time and adaptation options.

Undernourished patients have demonstrated a blunted response to hypercapnia that improves after as little as 1 week of adequate nutritional support. This response is thought to result from protein administration, as evidenced by decreased partial CO2 pressure, increased minute ventilation, and improved breathing patterns after the start of PN. F rotein administration also may influence ventilatory demand by increased ventilatory response to hypoxia and hypercapnia. This stimulation may be altered by the amino acid composition of the protein source, with increased amounts of BCAAs having a greater effect compared with standard amino acids." Although this protein effect is potentially beneficial in some patients, excessive protein administration could theoretically lead to increased work of breathing and fatigue." ... 

A mathematical model of the control system for erythropoiesis is presented. It is postulated that the rate of erythropoiesis is controlled by a hormone, erythropoietin, which is released from the kidney in response to reduced renal oxygen supply. Equations are developed relating erythropoietin release to arterial oxyhemoglobin concentration, and hemoglobin production to plasma erythropoietin concentration, with appropriate time delays. Effects of plasma volume changes during hypoxia are included. The model simulates the dynamic response of the erythropoietic system to a step decrease in the pOt of inspired air. Contributions of the parameters and relationships to the predicted response are analyzed. The model response compares favorably with experimental data obtained from mice subjected to different degrees of hypoxia. 

It is a relatively safe potent volatile anaesthetic administered by inhalation. It is twice as potent as chloroform and 4 times that of ether. It may produce any depth of anaesthesia without causing hypoxia. Being a non-irritant, its inherent hypotensive effect retards capillary bleeding and renders a comparatively bloodless field. 

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