67Cu for metabolic studies in milk cows.

Abstract

Primarily because of its half-life, the longest-lived radionuclide of copper, 67Cu (half-time 61.7 h), is often the isotope of choice for application in metabolic studies. However, large-scale production of 67Cu is cumbersome. The 67Cu used in this study was produced in a cyclotron by exposing a zinc target to a beam of accelerated protons. Radiochemical purification was achieved by solvent extraction, electroplating and ion-exchange, in that order. The resulting dilute acidic solution contained no measurable activity apart from 67Cu and 64Cu. After the injection in cows, the 64Cu component of the preparation of radiocopper could be used during the first days of the experiment for external radioassay of the liver. The 67Cu could be followed in metabolic products for over 3 weeks. It is concluded that the isotope 67Cu in batches of about 100 mu Ci can very well be used for metabolic excretion studies even on large animals. (Abstract retrieved from CAB Abstracts by CABI’s permission)