Intestinal absorption of aluminium: studies in the isolated perfused rat intestinal preparation

Aluminium (Al) absorption was studied using an isolated in vitro vascularly perfused rat intestinal preparation. Al was introduced into the lumen as AlCl3, Al(NO3)3 or Al lactate to give final concentrations equivalent to 0.625, 1.25, 2.50, 5.00, or 10.00 g/L of Al. The intestinal tissue remained viable up to 5.0 g/L of Al. The amount of Al associated with intestinal tissue after 90 min increased with the concentration up to 5 g/L of Al for chloride and nitrate and 10 g/L of Al for lactate. The time course of Al disappearance from the lumen followed a single exponential decay when the intestinal lumen was perfused with 0.625 g/L of Al as the chloride salt. The total amount of Al appearing in the vascular perfusate after 90 min was always small. Absorption quotes ranged between 0.005-3.2% depending on the salt and concentration used. Addition of transferrin to the VM caused a 2-fold increase in the amount of Al appearing in the vascular effluent in comparison with controls when 1.25 g/L of Al as AlCl3 was introduced into the lumen. Al tissue content was not affected.