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 super(14)C, super(26)Al, and super(41)Ca. Until now, tracer studies of aluminum kinetics have not been possible because aluminum has only two isotopes, with half-lives of 6.5 min ( super(29)Al) and 7 x 10 super(5) yr ( super(26)Al), 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 super(26)Al. Kinetics were similar in the two animals; similar to 75% of intravenously injected tracer super(26)Al was excreted in the urine in the first 24 h as was similar to 80% after 3 wk. Renal clearance of super(26)Al was similar to 0.75 ml multiplied by min super(-1) multiplied by kg body wt super(-1) in both rats. The results clearly demonstrate the potential of this technique for isotope tracer studies in animals as well as in humans.