Synthesis, DTPA coupling and radio labeling of cationic aminodextran
In glomerular diseases, the normal anionic charge of the basement membrane is lost at an early stage. Glomerular damage in rats has been detected more readily with cationic dextrans than with inulin. Hence, the authors attempted to demonstrate this phenomenon in vivo in rats with labeled cationic dextran. Aminated Dextran (AMDEX) was prepared by treating Dextran(mol. wt approx. = 15k) with sodium methoxide followed by a bromethylamine HBr in DMSO resulting in 10-25 aminogroups per mole. DTPA cyclic dianhydride was coupled to AMDEX using a weight ratio of 1:10 in 0.2 - 1.0 ml 0.42 M Hepes buffer at pH 7.4. Free DTPA was removed by gel filtration (Sephadex P6DG) or by using Centricon-10 (AMICON) centrifugal microconcentrators. AMDEX coupled with DTPA was labeled with Indium-111 in 0.25 M acetate buffer. Labeling yields were >90% by gel chromatography and electrophoresis (pH8.2 Barbitol buffer). AMEXDTPA was labeled also by ligand exchange with Tc-99m-Sn-citrate at neutral pH with a labeling yield of 30%. On electrophoresis, all the labeled samples retained their cationic character. The distribution of purified In-111 AMDEX, was compared with simultaneously IV injected Tc-99m DTPA in rats. The 2 hour urinary excretion, and renal clearance (calculated from the biexponential plasma clearance) were slower (70 to 80%) than those of DTPA, due to the larger molecular size of AMDEX. By 1 hr., 5% of the administered activity was retained in each kidney, probably due to adherence to anionic binding sites.
- Research Organization:
- Upstate Medical Center, Syracuse, NY
- OSTI ID:
- 6932764
- Report Number(s):
- CONF-840619-
- Journal Information:
- J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 25:5; ISSN JNMEA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ALKALI METAL COMPOUNDS
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD SUBSTITUTES
BODY
CARBOHYDRATES
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHALCOGENIDES
CHELATING AGENTS
CHEMICAL PREPARATION
CHROMATOGRAPHY
CITRATES
DAYS LIVING RADIOISOTOPES
DEXTRAN
DIAGNOSIS
DIAGNOSTIC USES
DISEASES
DMSO
DRUGS
DTPA
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
FILTRATION
GEL PERMEATION CHROMATOGRAPHY
GLOMERULI
HEMATOLOGIC AGENTS
HOURS LIVING RADIOISOTOPES
INDIUM 111
INDIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
LABELLING
MAMMALS
MEMBRANES
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
POLYSACCHARIDES
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
RATS
RODENTS
SACCHARIDES
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM OXIDES
SULFOXIDES
SYNTHESIS
TECHNETIUM 99
TECHNETIUM ISOTOPES
TIN COMPOUNDS
TRACER TECHNIQUES
UROGENITAL SYSTEM DISEASES
USES
VERTEBRATES
YEARS LIVING RADIOISOTOPES