The chemical structure of lipoprotein (a) is similar to that of LDL from which it differs due to the presence of apolipoprotein (a) bound to apo B100 via one disulfide bridge. disease. However the risk of black subjects must be considered. Sex and age have little influence on lipoprotein (a) levels. Lipoprotein (a) homology with plasminogen might lead to interference with the fibrinolytic cascade accounting for an atherogenic mechanism of that lipoprotein. Nevertheless direct deposition of lipoprotein (a) on arterial wall can be a possible system lipoprotein (a) becoming more susceptible to oxidation than LDL. Many prospective studies possess verified lipoprotein (a) like a predisposing element to atherosclerosis. Statin treatment will not lower lipoprotein (a) amounts in a different way from niacin and ezetimibe which have a tendency to decrease lipoprotein (a) although verification of ezetimibe results can be pending. The decrease in lipoprotein (a) concentrations is not demonstrated to decrease the risk for coronary Tubacin artery disease. Whenever higher lipoprotein (a) concentrations are located and in the lack of far better and well-tolerated medicines a more stringent and strenuous Rabbit Polyclonal to Bax (phospho-Thr167). control of the additional coronary artery disease risk elements should be wanted. studies show that apo(a) synthesis occurs in hepatocytes and its own association with apo B100 should happen on cell surface area8. Therefore the liver continues to be referred to as the main site of Lp(a) synthesis. There is absolutely no coordination between your synthesis pathways of apo(a) and of apo B100 as there is absolutely no coordination between your synthesis of Lp(a) and of plasminogen its structural analogue. Much like LDL Lp(a) will not are based on the catabolism of another lipoprotein9. In people with raised triglyceridemia Lp(a) can be reduced probably because of a rise in the plasma lipoprotein clearance10. However when VLDL lipolysis was stimulated by heparin inoculation during catheterization in patients with normal lipid levels there was a reduction in Tubacin triglyceride levels with no change in Lp(a) concentration. This confirms that Lp(a) levels are not related to the lipoprotein lipase activity11. The way Lp(a) cellular uptake occurs has not been well established. Several studies have shown that Lp(a) binds to specific LDL receptors although with less affinity. Two possible explanations for that difference in affinity are: (1) some Lp(a) domains near the domain of LDL-receptor binding would be covered by apo(a); or (2) apo(a) would not bind to apo B100 in the receptor binding site causing changes in the apo B100 binding region. However it is worth noting that when apo(a) is dissociated from Lp(a) by cleavage of disulfide bridges the binding capacity of the lipoprotein increases becoming equivalent to that of LDL12. There is evidence that the LDL receptor might not be so important in Lp(a) plasma removal. Large clinical studies have reported that statins have no effect on Lp(a) concentrations. Because statins induce superexpression of LDL receptors greater Lp(a) plasma removal and consequent lower Lp(a) plasma levels would be expected if the receptor was essential for that process. Other receptors such as asialoglycoprotein receptors megalin receptors and macrophage scavenger receptors can also be involved in Tubacin Lp(a) uptake13. The capacity of macrophages to uptake Lp(a) is important because the excessive uptake of lipoproteins by macrophages with their subsequent transformation into foam cells is the major mechanism of atherogenesis. Other studies have shown elevated Lp(a) plasma levels in patients with heterozygous Tubacin familial hypercholesterolemia known to have deficiency of LDL receptors. Considering that such increase is a direct consequence of a defect in the receptor that interacts with the apo Tubacin B100 of Lp(a) the genetic defect in apo B100 would be expected to cause that same situation similarly to that with LDL. However that condition could not be confirmed because the Lp(a) plasma levels were not affected by apo B100 mutation. In addition only a small fraction of Lp(a) binds to hepatoma cells via LDL receptor and the major part of lipoproteins associates with those cells via another cellular mechanism14. Thus although the LDL receptor acts upon Lp(a) removal its role in that process is limited. The Tubacin experiences carried out so far have not evidenced a physiological function for Lp(a) in lipid transportation or metabolism regulation. Up to now Lp(a) remains conceptually only a “pathogenic.