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Title: Nuclear medicine progress report for quarter ending June 30, 1984

Technical Report ·
OSTI ID:6448515

Because of the importance of using iodine-123-labeled structurally modified fatty acids for the evaluation of regional differences in myocardial fatty acid uptake to various types of disease, a detailed comparison of the relative myocardial uptake and retention in rats of two model, methyl-branched fatty acids in comparison to the unbranched analogues was evaluated in fasted and unfasted rats. 15-((/sup 123/I)iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 15-((/sup 125/I)iodophenyl)pentadecanoic acid (IPP) were combined and administered to groups of fasted and unfasted rats. Rats were sacrificed and the tissue distribution of radioactivity evaluated at several time intervals from 2 min to 2 h. In the same manner, 19-(/sup 123/I)iodo-3-(R,S)-methyl-18-nonadecenoic acid (BMIVN) and 19-(/sup 125/I)iodo-18-nonadecenoic acid (INN) were evaluated in groups of fasted and unfasted rats. These results showed that in unfasted rats the relative heart myocardial clearance and blood levels of the methyl-branched and unbranched fatty acids were similar. In contrast, in fasted rats the straight chain analogues showed a rapid myocardial washout, while the branched analogue showed much longer retention. The subcellular distribution of these radiolabeled fatty acids in heart homogenates obtained after intravenous administration to rats was also evaluated. Under non-fasting conditions the distribution profiles in microsomes, mitochondria and cycloplain were similar. Under fasting conditions, however, there was a shift of the subcellular distribution profile for the straight chain analogue and with a relative amount of radioactivity from the mitochondrial and microsomal fractions. 4 references, 10 figures.

Research Organization:
Oak Ridge National Lab., TN (USA)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
6448515
Report Number(s):
ORNL/TM-9343; ON: DE85000170
Country of Publication:
United States
Language:
English