INVESTIGATIONS OF THE HUMAN ALUMINUM BIOKINETICS WITH AL-26 AND AMS

Continuing the investigations on two healthy volunteers and on two pat ients with renal failure, the aluminium biokinetics in humans was stud ied by administering oral and intravenous doses of Al-26 to three furt her healthy volunteers. Blood samples were drawn at times between 20 m in and half a year after administration of the doses. The complete dai ly urine was collected during the first nine days, spot urine samples were taken at later times when blood samples were obtained. Creatinin renal clearances and haematocrit values were also obtained in the time period of the investigations. The Al-26 concentrations of the samples were measured using the Munich Tandem accelerator. An open compartmen t model was developed to describe the time dependences of the measured Al-26 concentrations in blood and urine and to establish the human Al biokinetics. The model comprises stomach and duodenum for oral admini stration, a central compartment consisting of blood plasma and interst itial fluid with transferrin and citrate binding and three peripheral compartments which are needed to describe the time dependence for the long observation period of up to three years. Excretion of Al was main ly described from plasma citrate via the kidneys into the urine and to a lesser extent from the plasma transferrin via the liver into the st ool. Time constants between the compartments, fractional intestinal ab sorption factors and aluminium renal clearances were derived. It was f ound that the sizes of two peripheral compartments of the patients wit h renal failure were different to those of the healthy volunteers.