title: TC-99m(Sn)-N-pyridoxylaminates: a new series of hepatobiliary imaging agents.
abstract: Three derivatives of N-pyridoxylamino acid were synthesized: Tc-99m(Sn)-N-pyridoxylphenylalanine, -N-pyridoxyltryptophan, and -N-pyridoxyl-5-methyltryptophan. The chemical and biologic properties of each complex was found to be quite analogous to those of the corresponding Tc-99m(Sn)pyridoxylideneaminate. In rats, Tc-99m(Sn)-N-pyridoxyl-5-methyltryptophan [Tc-99m(Sn)PHMT] showed rapid blood clearance, fast hepatobiliary transit, low urinary excretion, and no intestinal reabsorption. Over 90% of the dose arrived in the intestine through the liver at 30 min after i.v. administration, whereas only 2% of the dose escaped through the kidneys. In rabbits the gallbladder was clearly visualized within 5 min of injection and no renal or bladder images were noted on any scintiphotos. The BSP (sulfobromophthalein) intervention study revealed that the biliary excretion of Tc-99m(Sn)PHMT is much more resistant than that of TC-99m(Sn) diethyl-IDA to the intervention of BSP and hence to serum bilirubin. Toxicity studies on PHMT and Sn-PHMT indicated a wide margin of safety for the proposed human dose.
mesh_terms: D000818:Animals; D001659:Biliary Tract / Q000000981:diagnostic imaging*; D005260:Female; D008099:Liver / Q000000981:diagnostic imaging*; D015609:Organotechnetium Compounds; D010649:Phenylalanine / Q000031:analogs & derivatives*; D011736:Pyridoxine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D011817:Rabbits; D011877:Radionuclide Imaging; D051381:Rats; D011919:Rats, Inbred Strains; D011933:Reagent Kits, Diagnostic; D013667:Technetium / Q000378:metabolism; D014018:Tissue Distribution; D014364:Tryptophan / Q000031:analogs & derivatives*
chemical_list: D015609:Organotechnetium Compounds; D011933:Reagent Kits, Diagnostic; C034836:technetium Tc 99m (Sn)-N-pyridoxyl-5-methyltryptophan; C025772:technetium Tc 99m (Sn)-pyridoxylidenetryptophan; C031862:technetium Tc 99m pyridoxylphenylalanine; D010649:Phenylalanine; D013667:Technetium; D014364:Tryptophan; D011736:Pyridoxine