Fibrinogen labelled

Fibrinogen labeled with and Br B-H reagent more suitable than product labeled with I by iodine monochloride, CT, or LP methods for in vivo clearance studies... 

In order to approach more closely to the blood system itself and to determine the influence of other proteins on fibrinogen adsorption, we undertook studies of competitive adsorption between fibrinogen and other plasma proteins. In these studies, etimes the adsorption of only fibrinogen (labelled with I) was followed sometimes that of both fibrinogen and a second protein (labelled with I) were followed. 

Injections of 131I given to detect pulmonary embolism can result in false-negative results in the 12SI-labeled fibrinogen test for venous thrombosis. 

Fig. 2. Schematic diagram of the three pairs of polypeptide chains of fibrinogen. The Aa, B/3, and 7 chains are represented by bars with lengths proportional to the number of amino acid residues in each chain and the N- and C-terminal ends of the chains are labeled. The coiled-coil regions are indicated by the diagonally striped boxes, while the intra- and interchain disulfide bonds are indicated by solid lines. Carbohydrate attachment sites are labeled with CHO, while thrombin and major plasmin cleavage sites are indicated by T and P, respectively. (Adapted from Fig. 12-1 of Hantgan et al., 2000.)...

Takeda, Y. (1966). Studies of the metabolism and distribution of fibrinogen in healthy men with autologous 125-I-labeled fibrinogen./ Clin. Invest. 45, 103-111. 

Fig.6 Competitive binding of bovine serum albumin [BSA] vs. bovine serum fibrinogen [Fg] (A), and reversibility of BSA adsorption (B), on PEU surfaces modified by MPEO-derived SMAs, as determined by radioiodine labeling [80,81]. Reproduced from [177,178]...

From a strict biochemical point of view a clear-cut definition of the role of the liver in the biosynthesis of any particular plasma protein can be made only when the particular protein has been clearly and cleanly isolated, as in the case of fibrinogen. The practical difficulties of effecting such isolations on a small scale from isotopic labeling studies of the plasma proteins, such as we have described, seriously militate against such a detailed demonstration at present. The use of fractionation techniques with greater resolving power such as acrylamide gel electrophoresis already show some promise in our laboratory toward affording a more definitive picture of the biosynthetic role of the liver and the nonhepatic tissues in plasma protein production. 

Direct immunofluorescence studies are performed on 4mm thick cryostat sections, which are incubated with fluorescein isothiocyanate-labeled goat anti-rat IgG, goat anti-rat C3, goat anti-rat fibrinogen and goat anti-rabbit IgG. (Note these procedures may also be performed on the paraffin sections using standard immunohistochemistry techniques). 

The competition reaction is characterized by one buffer value (bidistilled water) and various concentrations of non-labeled fibrinogen or test compound. 

Non-specific-binding The non-specific binding of 125I-fibrinogen is defined as the radioligand binding in the presence of 10 5 M of non-labeled fibrinogen. 

I-fibrinogen versus non-labeled drug by a computer-supported analysis of the binding data. 

Radiolabels are also important tools in pharmacokinetic studies for detecting various immune modalitiesand also for different kinds of external injuries. Toth studied the distribution of I-labeled fibrinogen in rats during endotoxin shock. 

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