TISSUE DISPOSITION OF (26)ALUMINUM IN RATS MEASURED BY ACCELERATOR MASS-SPECTROMETRY

A trace quantity of (26)aluminum (Al-26) Was administered intravenousl y to 1 normal and 1 uremic rat. After a 3-week period, the animals wer e sacrificed and samples of bone, muscle, kidney, liver, heart, and br ain were analyzed for their Al-26 content. In the normal and uremic ra ts, most of the tissue Al-26 Was found in bone amounting to 0.9% and 2 .0%, respectively, of administered dose/g dry weight of tissue. Much s maller amounts of isotope were found in the other tissues in both anim als. In the normal rat, the descending order of Al-26 content in other tissues was: kidney, 0.2% > liver, 0.06% > heart, 0.03%, > brain and muscle, 0.02%. In the uremic rat, the same order of tissue Al-26 conte nt was found with kidney, 0.37% > liver, 0.06% > heart, 0.02% > brain and muscle, 0.01% per g dry weight of tissue. When expressed per g wet weight of tissue in the 2 animals, a similar order of tissue Al-26 co ntent was found. In comparing the amount of Al-26 in the bone of the 2 rats, the uremic animal was found to have more than twice that found in the bone of the normal rat when expressed either per g dry or wet w eight of bone. However, Al-26 content of other tissues was similar in the 2 animals. This suggests that uremic bone may have a greater affin ity for aluminum than normal bone, but kidney, liver, brain, heart, an d muscle appear to behave similarly in uremic and normal rats in regar d to incorporation of a single trace dose of isotope in the 3-week tim e frame of the present study.