Plasma protein albumin

Water-soluble compounds are naturally easily transported in the blood. Non-soluble compounds are usually transported bound to plasma proteins (albumins). This binding is reversible in most cases but may vary remarkably. The degree of protein binding may vary between 50% and 99%. The proportion of the free (unbound) compound in the circulation is the amount of the compound that can reach the tissues and thus the target organs. Very lipid-... 

Table 50-2 summarizes the functions of many of the plasma proteins. The remainder of the material in this chapter presents basic information regarding selected plasma proteins albumin, haptoglobin, transferrin, ceruloplasmin, aj-antitrypsin, aj i roglobulin, the immunoglobulins, and the complement system. The lipoproteins are discussed in Chapter 25. 

Polyphenols are not found free in the blood but are bound to plasma proteins. Albumin is the primary protein responsible for the bindings of several polyphenols and their metabolites (i.e., quercetin, kempferol, isorhamnetin), but no data are available for anthocyanins. However it is probable that anthocyanin derivatives also bind to albumin and the degree of that binding may affect the clearance rate and the delivery to tissues of these compounds as well. 

Calcium is present in three forms e.g., as free calcium ion, bound to plasma protein albumin and in diffusable complexes. The endocrine system, through parathyroid hormone and calcitonin, helps in keeping the concentration of ionized plasma calcium in normal level. Decrease in plasma levels of ionized calcium leads to increased parathyroid hormone secretion. Parathyroid hormone tends to increase plasma calcium level by increasing bone resorption, increasing intestinal absorption and increasing reabsorption of calcium in kidney. Vitamin D acts by stimulating... 

Our laboratory has for a number of years championed the use of the plasma protein albumin as an effective carrier to protect enzymes for use in enzyme-replacement therapy. Albumin is the moat abundant plasma protein and has a circulation half-life of as much as 6(1-72 hours. It has both hydrophilic and... 

Example Isotretinoin (Accutane) Route PO Pregnancy category X Pharmacokinetic Absorption enhanced when taken with a high-fat meal. It binds to plasma proteins (albumin), metabolized in the liver and excreted in feces and urine. 

The penicillins and cephalosporins ((3-lactam antibiotics) are weak organic acids that, due to their low pfCa values, are predominantly ionized in the blood plasma. Binding of (3-lactam antibiotics to plasma proteins (albumin) differs between individual penicillins (from 16-22% for ampicillin to over 80% for cloxacillin and nafcillin) and individual cephalosporins (from 15-20% for cephalexin and cefadroxil to over 80% for cefazolin, cefoperazone and ceftriaxone). The consequence of extensive protein binding on clinical efficacy of (3-lactam antibiotics is incompletely understood, apart from decreasing the availability of the drug (unbound fraction) for extravascular distribution. Because of their high degree of ionization in the plasma and consequently relatively low solubility in lipid, the extravascular distribution of (3-lactam... 

One of the smallest and the most abundant plasma proteins, albumin plays a significant role in osmotic regulation and transport of free fatty acids. Albumin is synthesized in the liver at a rate of approximately 14 g/d, or 10% of the total protein synthesis of the body. Deviations from the normal concentration of albumin in plasma can indicate the state of hepatic function. Albumin is also present in interstitial fluid. 

Salicylates are highly bound to plasma protein albumin, with binding being concentration dependent. At low therapeutic concentrations of 100 pg/mL, approximately 90% of aspirin is plasma protein bound, whereas at higher concentrations of approximately 400 pg/mL, only 76% binding is observed. Plasma protein binding is a major factor in the drug interactions observed for salicylates. 

The rate constants in Equation 2 include the solution concentration of the protein which is assumed to be constant in the initial stages of adsorption. Since the concentrations of plasma proteins albumin y-globulin fibrinogen are in the ratio 42.0 22.4 5.6, the rate constants from Equation 2 were weighted accordingly to give the values shown in Table II. Thus, the apparent rate constant,, ... 

Static Adsorption of Plasma Proteins on Glass. Initial studies of the interaction of proteins with artificial surfaces concerned the highly simplified situation of static adsorption on glass from solutions of purified radiolabeled human plasma proteins. Albumin was chosen as a major plasma protein known for its non thrombogenic properties (5>6). Fibrinogen and fibronectin, on the contrary, are major proteins of plasma which enhance platelet and cellular adhesion (4.5.7.23-25). 

Sotalol is only negligibly bound (28) to plasma proteins (albumin and alphai-acid glycoprotein). The volume of distribution of sotalol is... 

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