1983 Volume 103 Issue 6 Pages 644-649
Attempts to improve adrenal imaging with 131I-6β-iodomethyl-19-norcholest-5 (10)-en-3β-ol (NCL-6-131I) were made. Various NCL-6-131Is with higher specific activity than those used clinically were prepared. An increase in specific activity of NCL-6-131I had no significant effect on the rat adrenal uptake, but caused an increase in the liver concentration of radioactivity. Lipid extraction and radiochromatographic analysis showed the presence of unchanged NCL-6-131I in the liver, but in the adrenal the esterified form of NCL-6-131I was predominant. Autoradiochromatogram of faeces extract indicated the presence of a radioactive spot with an Rf value slightly lower than that of NCL-6-131I. Effects of N-(4-hydroxyphenyl) salicylamide and ursodeoxycholic acid on rat biodistribution of NCL-6-131I were also examined. No significant effect on the adrenal uptake and adrenal-liver ratio of NCL-6-131I was observed in either case.
