Metabolism, reduced

Injury any physical or biological response to pollutants, such as a change in metabolism, reduced photosynthesis, leaf necrosis, premature leaf drop, or chlorosis. 

Increased Glucose Metabolism Reduces the Output of Free Fatty Acids... 

The inability to hydrolyze fructose 1-phosphate for further metabolism reduces availability of inorganic phosphate and decreases ATP levels. 

Zidovudine was the first drug of the class. It is a dideoxythymidine analog. It has to be phos-phorylated to the active triphosphate. This triphosphate is a competitive inhibitor of HIV reverse transcriptase. By incorporation into viral DNA it also acts as a chain-terminator of DNA synthesis. Mutations in viral reverse transcriptase are responsible for rapidly occurring resistance. Zidovudine slows disease progression and the occurrence of complications in AIDS patients. It is readily absorbed. However, first pass metabolism reduces its oral bioavailability with some 40%. It readily crosses the blood-brain barrier. Plasma protein binding is about 30%. Zidovudine is glucuronidated in the liver to an inactive metabolite. Its elimination half-life is 1 hour. 

Metabolism Reduced hepatic mass Often decreased first-pass... 

Lidocaine Sodium channel (INa) blockade Blocks activated and inactivated channels with fast kinetics does not prolong and may shorten action potential Terminate ventricular tachycardias and prevent ventricular fibrillation after cardioversion IV first-pass hepatic metabolism reduce dose in patients with heart failure or liver disease Toxicity Neurologic symptoms... 

Theophylline [NE] Increased theophylline metabolism reduced theophylline effect. 

Corticosteroids [P] Increased corticosteroid hepatic metabolism reduced corticosteroid effect. 

Mexiletine [NE] Increased mexiletine metabolism reduced mexiletine effect. 

NAD) and nicotinamide adenine dinucleotide phosphate (NADP), are the universal carriers of hydrogen and electrons, or metabolic reducing power. Many redox processes may be linked together in electron transport chains. 

Rifampin Induction of hepatic microsomal drug-metabolizing enzymes. Corticosteroids [P] Increased corticosteroid hepatic metabolism reduced corticosteroid effect. 

Newman WG et al (2008) Impaired tamoxifen metabolism reduces survival in familial breast cancer patients. Clin Cancer Res 14 5913-5918... 

Administration of the CYP2D6 inhibitor quinidine, 200 mg/day for 2 days, to the extensive metabolizers reduced the oral clearance of venlafaxine to the level seen in poor metabolizers. Quinidine had no effect on venlafaxine clearance in subjects who were poor metabolizers before treatment. The authors suggested that poor metabolizers may be at particular risk of venlafaxine toxicity, as could subjects who take inhibitors of CYP2D6. 

MAOIs H2 RECEPTOR BLOCKERS-CIMETIDINE t plasma concentrations of modobemide (by up to 40%) Due to cimetidine inhibiting its metabolism Reduce dose of modobemide to one-half to one-third of original, then alter as required... 

C4 also metabolism reduces transpiration by lowering the CO2 compensation point (Fig. 13.14). Photosynthesis is slower when there is less CO2 about, and the compensation point is definerl ac fVio TPOd needed to give net photosynthesis. 

Adaptive effect An adaptive effect enhances an organism s performance as a whole and/or its ability to withstand a challenge. An example of an adaptive effect is an increase in hepatic smooth endoplasmic reticulum, but only if hepatic metabolism reduces the chemical s toxicity. 

Genistein and daidzein directly affect testosterone metabolism, reducing the toxic metabolites of testosterone. Genistein, an isoflavone, also seems to slow or prevent the metastasis of invasive cancer cells. It is believed to work by preventing the formation of new blood vessels to cancerous tumors. Histoculture studies of genistein have shown that this phytochemical reduces the growth of prostatic cancer tissue. 

Galantamine metabolism reduced by some cytochrome P450 inhibitors (e.g. 

The effects of carbon disulfide on the microsomal drug metabolizing system were demonstrated in rats by Freundt et al. (1975). Exposure of rats by inhalation to low concentrations of carbon disulfide (20-400 ppm for 8 hours) inhibited microsomal drug metabolism. This was reflected by increased hexobarbital sleep times. Pretreatment of rats with SKF-525A, an inhibitor of cytochrome P-450-mediated metabolism, reduced the liver damage from carbon disulfide in phenobarbital-pretreated animals (Bond and DeMatteis 1969). 

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