Iodohippurate

Cardiac nuclear imaging using Tc -red blood cells can measure the fraction of blood pumped by the heart during each beat. Tc -DTPA and sodium (9-iodohippurate, C H INNaO, are used to measure renal function of the kidney. The enhanced or diminished uptake of... 

Nucleophilic substitution of aryl halides is a facile route for activated systems, for instance in the displacement of CT from 2,4-dinitrochlorobenzene with Nal358. The exchange of o-iodohippuric acid has been rationalized by suggesting the stabilization of the intermediate complex by delocalization of the negative charge359 (equation 174). 

Hippuran [Mallinckrodt], TM for brand of iodohippurate sodium, a water-soluble X-ray contrast medium. 

Grade USP lists iodinated 131I serum albumin, rose bengal sodium 131I injection, sodium iodide 131I capsules and solution, sodium iodohippurate 131I injection. 

Sodium iodohippurate[ I] injection Sodium iodohippurate[ I] injection Sodium chromate[ Crj sterile solution Sodium phosphate[ P] injection... 

Since the introduction of Tc-l,l-EC as a tubular radiotracer (Verbruggen et al. 1992), clinical verification of the pharmacokinetic parameters has been obtained in normal controls (Van Nerom et al. 1993) and in patients (Gupta et al. 1995 Kabasakal et al. 1995), using standard procedures and also by comparison with the reference compounds orilio-iodohippurate (OlH) labeled with iodine-125 and with " Tc-mercapto-acetyltriglycine (MAG3) (Kabasakal et al. 1995 Ozker et al. 1994 Stoffel et al. 1996). Tc-EG complex showed high similarity with OIH with respect to plasma clearance and elimination half-times (Ozker et al. 1994 Van Nerom et al. 1993). " Tc-EC was... 

Stoffel M, Jamar F, Van Nerom C, Verbruggen AM, Besse T, Squifflet JP, Beckers C (1996) Techne-tium-99m-L,L-ethylenedicysteine clearance and correlation with iodine-125 ort/zo-iodohippurate for determination of effective renal plasma flow. Eur J Nucl Med 23 365-370 Van Nerom CG, Bormans GM, De Roo MJ, Verbruggen AM (1993) First experience in healthy volunteers with technetium-99m L,L-ethylenedicysteine, a new renal imaging agent. Eur. J Nucl Med 20 738-746... 

The similarity of Tc-MAG3 with (o-iodohippurate) has been demonstrated... 

The mechanism of excretion is predominantly based on renal tubular secretion. The TER of " Tc-MAG3 is 0.55 of the reference para-amino-hippurate ([PAH] 1.0) in comparison, orf/io-iodohippurate (OlH) shows a value of 0.83 (Bubeck et al. 1987). Using this coefficient (0.55), Tc-MAG3 may substitute for OlH as an indicator of effective renal plasma flow (ERPF) (Bubeck et al. 1990). 

Ci8H22N208Rh2, Tetra- -acetato-bis(pyridinerhodium(lI)), 44B, 882 Ci8H22Nb30iOf Hydrido-/X3"Oxo-tri Ai hydroxo-tri-Ai"formato-tri-triangulO cyclopentadienylniobium(IV), 39B, 710 Cl8H2aCuI2N2O11, Copper(ll) m-iodohippurate pentahydrate, 41B, 1121 Ci8H26CuOi2f Copper(II) p-methoxyphenoxyacetate tetrahydrate, 41B, 1022... 

A procedure for the analysis of natural iodine in aqueous solutions of iodohippuric acid (57) has utilized a freezing technique for the preparation of the sample for irradiation. Irradiation of a frozen sample rather than a solution has a number of advantages, the pressure in irradiation containers caused by the radiolysis of water is reduced substantially losses of iodine due to vaporization and also to adsorption on container walls are greatly minimized and interference from nuclides from container walls is avoided. 

When the peptide bond between glycine and lysine is cleaved, meta-iodohippuric acid is released from the conjugate. For comparison, two additional radioiodinated Fab fragments were prepared. Meto-iodohippuric acid was conjugated to Fab fragments though an amide bond to prepare MPH-Fab by procedures similar to those employed for HML-Fab. 

The radioactivity excreted in the urine for 6 hours postinjection of HML-Fab was then analyzed to assess the present chemical design of radiolabeled antibody fragments. On size-exclusion HPLC, more than 85 % of the radioactivity was eluted at the low molecular weight fractions and about 12 % of the radioactivity was eluted in fractions similar to those of the intact Fab fragment. On reversed-phase HPLC of the urine sample, over 93 % of the low molecular weight fractions had a retention time identical to that of ffjeto-iodohippuric acid. These findings indicated that the low renal radioactivity levels of HML-Fab were attributed to rapid and selective release of /weto-iodohippuric acid in the kidney. 

Fab. These findings suggested that HML-Fab released meto-iodohippuric acid before the antibody fragment was transported to and metabolized in the lysosomes of the renal cells. 

To further understand the mechanisms responsible for the rapid and selective release of meto-iodohippuric acid from [ I]HML-Fab fragment, subcellular localization of the radioactivity was investigated at 10 and 30 minutes postinjection of the three radioiodinated Fab fragments. Both [ I]MIH-Fab and l-Fab showed the major radioactivity at membrane fractions at 10 minutes postinjection. At 30 minutes postinjection, the majority of the radioactivity of the two Fab fragments migrated to the lysosomal fractions. This suggested that most of the administered Fab fragments would be transported to and metabolized in the lysosomal... 

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