Iron-58 and neutron activation analysis: a non-radioactive method for tracing hemoglobin iron.
To develop a non-radioisotopic alternative to radioactive Fe-59 as a hemoglobin iron tracer, we evaluated Fe-58 and neutron activation analysis (NAA). Upon irradiation with thermal neutrons, stable isotope Fe-58 is converted to radioactive Fe-59 through (n,gamma) neutron reaction; its radioactivity measured by a gamma counter is proportional to the original Fe-58 present. Organ samples from rats infused with Hb or saline were analyzed along with a 10 mg Hb as a standard (105 nanograms of Fe-58). The measured values of Fe-58 in tissues were compared with those derived from the literature tissue iron contents. The amount of Fe-58 in normal tissue is extremely low yet detectable by NAA demonstrating high sensitivity. Measured values of Fe-58 from tissues were generally correlated well with literature derived values (e.g., brain: 0.19 and 0.15 ng/mg tissue; kidney: 0.6 and 0.7 ng/mg tissue, respectively). The results indicate that Fe-58 can be used as a non-radioactive tracer for absorption, distribution, metabolism, and distribution studies of hemoglobin-based oxygen carriers.
Kim
H W
HW
Brown University, Providence, Rhode Island.
Yu
Y J
YJ
Greenburg
A G
AG
D000818:Animals; D001802:Blood Substitutes / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D005069:Evaluation Studies as Topic; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism*; D007501:Iron / Q000032:analysis / Q000378:metabolism*; D007503:Iron Isotopes; D008297:Male; D009501:Neutron Activation Analysis / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley
D001802:Blood Substitutes; D006454:Hemoglobins; D007503:Iron Isotopes; D007501:Iron