Ligand dissociation calcium

Most importantly, the results of these dynamic simulations offer an explanation for the effect of receptor blockers (Fig. 23). The model predicts that for the same equilibrium dissociation constant, /(D, the association/dissociation rate constants of receptor/ligand binding may determine whether or not receptor blockers affect calcium mobilization. The behavior extremes occur when association/dissociation rates are fast and slow relative to the rate of two-dimensional diffusion. 

The results of dietary zinc analysis need to be considered in terms of the availability of the zinc in the food for intestinal absorption. The zinc content of whole meals and the total daily zinc intake are not sufficient information on their own, without knowledge of factors which inhibit or promote intestinal absorption (O Dell, 1984). Free ionic zinc probably does not exist in the intestinal tract, zinc being bound to molecular species such as protein, amino acids, phytic acid, citrate and others. The bioavailability of the metal is determined by the nature of these zinc binding ligands. When the zinc complex is insolubie as in Zn-phytate, the uptake from diet is poor, whereas zinc-protein or zinc-amino acid complexes are more easily dissociated and are a good source of available zinc. Other dietary components affect zinc absorption such as the amount of iron, calcium and phosphate. 

---