Effect Oxygen consumption

Metabolic Functions. The functions of the thyroid hormones and thus of iodine are control of energy transductions (121). These hormones increase oxygen consumption and basal metaboHc rate by accelerating reactions in nearly all cells of the body. A part of this effect is attributed to increase in activity of many enzymes. Additionally, protein synthesis is affected by the thyroid hormones (121,122). 

A large number of thyroid hormone analogues have been tested for this effect (6). Among others, i-T (3) and 3,3 -T2 (5) and their propionic acid side-chain analogues decrease oxygen consumption at molar ratios of 50—200 1 of T. Nevertheless, no potent or clinically usehil peripheral antagonists have been found. 

Amiodarone dilates arteriolar vascular smooth muscle, especiady coronary arteries, and thus exhibits antianginal effects. Its effects on the peripheral vasculature to decrease resistance leads to a decrease in left ventricular stroke work and a decrease in myocardial oxygen consumption. The dmg rarely produces hypotension that requires discontinuation of the dmg (1,2). 

Verapamil. Verapamil hydrochloride is a pbenyl alkyl amine and is considered the prototype of the Class I calcium channel blockers. Verapamil is also a potent inhibitor of coronary artery spasm and is useful in Prinzmetal s angina and in unstable angina at rest. Verapamil produces negative chronotropic and inotropic effects. These two actions reduce myocardial oxygen consumption and probably account for the effectiveness of verapamil in chronic stable effort angina (98,99). Moreover, verapamil is an effective antihypertensive agent. 

Mallefet, J., and Baguet, F. (1993). Metabolic control of luminescence in isolated photophores of Porichthys effects of glucose on oxygen consumption and luminescence./. Exp. Biol. 181 279-293. 

Figure 10.3. Steady-state effect of ohmic-drop-free catalyst potential on current (bottom) and on the rates of hydrogen (A) and oxygen ( ) consumption (top) on Pt/graphite rH2 (=Iq =r ) =2.38-1 O 7 mol/s is the open-circuit catalytic rate Conditions as in Figure 10.2. Reprinted with permission from Nature, McMillan Magazines Ltd.3,4...

Charlton MN (1980) Hypolimnion oxygen consumption in lakes discussion of productivity and morphometry effects. Can J Fish Aquat Sci 37 1531-1539... 

In the water-like solvent tert-butyl alcohol, a-tocopherol was found to prevent lipid oxidation, showing a distinct lag-phase for oxygen consumption. This was in contrast to quercetin or epicatechin, which were only weak retarders of lipid oxidation without any clear antioxidative effect. Quercetin or epicatechin, when combined with a-tocopherol, increased the lag-phase for oxygen consumption as seen for a-tocopherol alone. The stoichiometric factor for a-tocopherol, a-TOH, as chain-breaking antioxidant has the value n = 2 according to the well-established mechanism ... 

Beyond this point, during more severe exercise associated with anaerobic metabolism, minute ventilation increases faster than the rate of oxygen consumption, but proportionally to the increase in carbon dioxide production. The mechanism of the ventilatory response to severe exercise involves metabolic acidosis caused by anaerobic metabolism. The lactic acid produced under these conditions liberates an H+ ion that effectively stimulates the peripheral chemoreceptors to increase ventilation. 

Carroll D, Turner JR and Prasad R (1986) The effects of level of difficulty of mental arithmetic challenge on heart rate and oxygen consumption. International Journal of Psychophysiology, 4(3), 167-173. 

Of all these sources for error, the first two are the most significant. The oxygen consumption method has been reported to be accurate within 15 percent, which is the additive effect of average E and the chemical expansion factor. This extreme error can happen only in the case of complete oxygen depletion. The error is substantially reduced for most cases when the oxygen level in the exhaust is larger than zero. 

Mule, M.B. and V.S. Lomte. 1994. Effect of heavy metals (CuS04 and HgCl2) on the oxygen consumption of the freshwater snail, Thiara tuberculata. Jour. Environ. Biol. 15 263-268. 

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