Vitamin interaction with

Uherova, R., Fedorova, N., and Dubravicky, J., The study of vitamin interaction with the reactive constituents of smoking agent. Die Nahrung, 37(1), 85-87, 1993. 

The nutrient sparing effect of antibiotics may result from reduction or elimination of bacteria competing for consumed and available nutrients. It is also recognized that certain bacteria synthesize vitamins (qv), amino acids (qv), or proteins that may be utilized by the host animal. Support of this mode of action is found in the observed nutritional interactions with subtherapeutic use of antibiotics in animal feeds. Protein concentration and digestibiHty, and amino acid composition of consumed proteins may all influence the magnitude of response to feeding antibiotics. Positive effects appear to be largest... 

Factor IX. This factor is dependent on the presence of vitamin K for its activity as a biologicaUy functional procoagulant glycoprotein. Factor IX is converted to its active form by XIa in the classic scheme of the intrinsic pathway. However, it can also be activated via interaction with Factor Xa or the complex Factor III plus Factor VII in the presence of calcium. 

Levodopa interacts with many different drugs. When levodopa is used with phenytoin, reserpine, and papaverine, there is a decrease in response to levodopa The risk of a hypertensive crisis increases when levodopa is used with the monoamine oxidase inhibitors (see Chap. 31). Foods high in pyridoxine (vitamin B6) or vitamin B6 preparations reverse the effect of levodopa However, when carbidopa is used with levodopa, pyridoxine has no effect on the action of levodopa hi fact, when levodopa and carbidopa are given together, pyridoxine may be prescribed to decrease the adverse effects associated with levodopa... 

Particular attention is given to the development of new mechanistic biomarker assays and bioassays that can be used as indices of the toxicity of mixtures. These biomarker assays are typically based on toxic mechanisms such as brain acetylcholinesterase inhibition, vitamin K antagonism, thyroxin antagonism, Ah-receptor-mediated toxicity, and interaction with the estrogenic receptor. They can give integrative measures of the toxicity of mixtures of compounds where the components of the mixture share the same mode of action. They can also give evidence of potentiation as well as additive toxicity. 

Figure 4.7. Possibilities for the synthesis of Vitamin K3. The small pore titaninm zeolite TS-1 cannot fit the large naphthalene molecule into its pore system, and thus is effective in this transformation. The larger titanium MTS material is capable of interacting with the molecule, and the desired transformation can take place.

The lag-phase measurement at 234 nm of the development of conjugated dienes on copper-stimulated LDL oxidation is used to define the oxidation resistance of different LDL samples (Esterbauer et al., 1992). During the lag phase, the antioxidants in LDL (vitamin E, carotenoids, ubiquinol-10) are consumed in a distinct sequence with a-tocopherol as the first followed by 7-tocopherol, thereafter the carotenoids cryptoxanthin, lycopene and finally /3-carotene. a-Tocopherol is the most prominent antioxidant of LDL (6.4 1.8 mol/mol LDL), whereas the concentration of the others 7-tocopherol, /3-carotene, lycopene, cryptoxanthin, zea-xanthin, lutein and phytofluene is only 1/10 to 1/300 of a-tocopherol. Since the tocopherols reside in the outer layer of the LDL molecule, protecting the monolayer of phospholipids and the carotenoids are in the inner core protecting the cholesterylesters, and the progression of oxidation is likely to occur from the aqueous interface inwards, it seems reasonable to assign to a-tocopherol the rank of the front-line antioxidant. In vivo, the LDL will also interact with the plasma water-soluble antioxidants in the circulation, not in the artery wall, as mentioned above. 

Renal osteodystrophy stems from disruptions in calcium, phosphorus, and vitamin D homeostasis through the interaction with the parathyroid hormone. 

Many dietary supplements have antiplatelet activity, which may increase the risk of bleeding when used concurrently with anticoagulants. Feverfew inhibits cyclooxygenase and phospholipase A2 and may interact with anticoagulants and potentiate the antiplatelet effect of aspirin. Other supplements that possess antiplatelet activity include but are not limited to garlic, ginkgo, vitamin E, vitamin A, and selenium. 

This suggests that either the P-CAR +, which is more polar than the parent p-CAR, can efficiently reorientate so as to interact with the vitamin C in the aqueous phase, or that the ascorbic... 

Burke, M., Edge, R., Land, E.J., and Truscott, T.G. 2001a. Characterisation of carotenoid radical cations in liposomal environments interaction with vitamin C. J. Photochem. Photobiol. B Biol. 60 1-6. 

Edge, R and TG Truscott. 1997. Prooxidant and antioxidant reaction mechanisms of carotene and radical interactions with vitamins E and C. Nutrition 13(ll/12) 992-994. 

Thus, vitamin C is able to replenish vitamin E, making the latter a much more efficient free radical inhibitor in lipid membranes. In addition, it has been suggested [9] that ascorbic acid can directly interact with the plasma membrane giving electrons to a trans-plasma membrane oxidoreductase activity. This ascorbate reducing capacity is apparently transmitted into and across the plasma membrane. 

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