Effects of chain length and tellurium position on the myocardial uptake of Te-123m fatty acids.
A series of Te-123m-labeled fatty acids has been synthesized and studied in rats. In the series of compounds studied, the position of the Te-123m heteroatom was not as important as the total chain length, which dramatically affected the heart uptake. Five minutes after injection, significant heart uptake (1.7-2.3% of injected dose) was observed for agents with C15, C17, and C21 chain lengths, in which Te-123m replaced a methylene group in either the 6, 9, 11, or 17 positions, and the heart-to-blood ratios were high. An important observation was the prolonged retention of radioactivity for at least one hour after injection. In contrast, agents with shorter C13 chain lengths, with Te-123m in either the 6 or the 9 position, exhibited only low heart uptake (0.1-0.3% of injected dose).
D000818:Animals; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D007553:Isotope Labeling; D007554:Isotopes; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D013329:Structure-Activity Relationship; D013691:Tellurium; D013997:Time Factors; D014018:Tissue Distribution
D005227:Fatty Acids; D007554:Isotopes; D013691:Tellurium