ACCELERATOR MASS-SPECTROMETRY - APPLICATION TO STUDY OF ALUMINUM KINETICS IN THE RAT

The advent of accelerator mass spectrometry (AMS) now permits the ultrasensitive detection of extremely long-lived isotopes, including C-14, Al-26, and Ca-41. Until now, tracer studies of aluminum kinetics have not been possible because aluminum has only two isotopes, with half-lives of 6.5 min (Al-29) and 7 x 10(5) yr (Al-26), neither of which is suitable for conventional studies. In a novel experiment we have employed AMS to study aluminum kinetics in a normal rat and a 5/6-nephrectomized rat over a 3-wk period of intravenous injection of a tracer dose of Al-26. Kinetics were similar in the two animals; approximately 75% of intravenously injected tracer Al-26 was excreted in the urine in the first 24 h as was approximately 80% after 3 wk. Renal clearance of Al-26 was approximately 0.75 ml.min-1 kg body wt-1 in both rats. The results clearly demonstrate the potential of this technique for isotope tracer studies in animals as well as in humans.