title: Radiopharmacological studies of 99mTc-CPI: experience with isolated rat atrial tissue.
abstract: Extraction, washout and chemical integrity of technetium(I) hexakis (2-carbomethoxy-2-isocyano propane), (99mTc-CPI) were evaluated in isolated contractile rat atrial tissue. 99mTc-CPI accumulated linearly over time at 32 degrees C with uptakes that were both concentration dependent and temperature sensitive. Uptake rates also increased with contractile strength, indicating a dependence of retention on metabolic status of the tissue. Retention indices showed that percent washout of 99mTc-CPI was much slower than control studies with 99mTcO4. HPLC analysis of retained radioactive products in atrial tissue showed most of the activity present as the 99mTc-CPI complex (75%). These observations in isolated rat atrial tissue help explain the interspecies differences in biodistribution of 99mTc-CPI and support the membrane potential dependent model for uptake and retention of technetium isonitrile complexes.
authors.affiliation: Departamento de Radiofarmacia, Centro de Investigaciones Nucleares, Fac. de Ciencias, Montevideo, Uruguay.
authors.forename: S
authors.initials: S
authors.lastname: Verdera
authors.forename: A
authors.initials: A
authors.lastname: Leòn
authors.forename: J F
authors.initials: JF
authors.lastname: Kronauge
authors.forename: E
authors.initials: E
authors.lastname: Leòn
authors.forename: B
authors.initials: B
authors.lastname: Souto
authors.forename: P
authors.initials: P
authors.lastname: Oliver
authors.forename: A
authors.initials: A
authors.lastname: Rodriguez
authors.forename: G
authors.initials: G
authors.lastname: Tamosiunas
authors.forename: A
authors.initials: A
authors.lastname: Esponda
authors.forename: A G
authors.initials: AG
authors.lastname: Jones
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006325:Heart Atria; D008297:Male; D008564:Membrane Potentials; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009570:Nitriles / Q000493:pharmacokinetics*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009570:Nitriles; D015609:Organotechnetium Compounds; C051216:technetium Tc 99m carbomethoxyisopropylisonitrile