Effect Calcium

Calcium effects. The biochemical effects of Ca "" in the cytoplasm are mediated by special Ca -binding proteins calcium sensors"). These include the annexins, calmodulin, and troponin C in muscle (see p. 334). Calmodulin is a relatively small protein (17 kDa) that occurs in all animal cells. Binding of four Ca "" ions (light blue) converts it into a regulatory element. Via a dramatic conformational change (cf 2a and 2b), Ca -calmodulin enters into interaction with other proteins and modulates their properties. Using this mechanism, Ca "" ions regulate the activity of enzymes, ion pumps, and components of the cytoskeleton. 

Perales, S., Barbera, R., Lagarda, M. J., and Parre, R. (2006). Fortification of milk with calcium Effect on calcium bioavailability and interactions with iron and zinc. /. Agric. Food Chem. 54, 4901 906. 

Therefore, other bioactive components in dairy products may have an effect on the metabolic syndrome either independently or in addition to the calcium effect. 

Javeri, H. Toledo, R., and Wicker, L. (1991). Vacuum infusion of citrus pectinmethylesterase and calcium effects on firmness of peaches. J. Food Sri. 56 739-742. 

Calcium Effects on Zinc Bioavailability for the Rat and the Human. It should be pointed out at this juncture that the nutrient requirement of calcium for the rat is much higher than for man. In fact, the molar ratio of calcium to zinc in excess of 660 1 is recommended for rat diets, while for man the ratio is between 80 1 and 160 1. To feed rats molar ratios of calcium and zinc similar to human requirements would necessitate either a very calcium deficient diet or one containing zinc at a level well in excess of the requirement. Neither choice is nutritionally suitable for demonstrating an effect of phytate on zinc availability. 

The role of Ca" " in the function of cell microskeleton, represented by microtubules and microfiliment, has been well documented (14,106,107), The contractile elements of this system are in some way responsible for the mobility of microorganelles and transport of granules to the membrane as well as excitability of the plasma membrane itself. Zinc may compete with calcium and thereby inhibit the calcium effect. 

In a recent study intravenous verapamil (4), an agent which inhibits transmembrane influx of calcium, effectively suppressed supraventricular tachycardias but proved much less beneficial in ventricular tachycardias.15... 

Calcite, PZC of, 207 Calcium, effect on fate of Feflll) precipitates, 63 Calorimetry, 280 Carbonate complexes of U, 311 Carbon dioxide,... 

Tashjian, A. H., Homeostasis of plasma calcium Effects of actinomycin D, parathyroidectomy and thyrocalcitonin. Endocrinology 77, 375-381 (1965). 

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