Light and electron microscopic study on the effect of aluminium hydroxide and the possible protective role of calcium carbonate on the lung of albino rat

ABSTRACT

While aluminium is not a heavy metal, it was found to be toxic. This study was conducted to show the effect of aluminium hydroxide on the lung and the effect of concomitant administration of calcium carbonate. Thirty rats were used and divided into three groups, ten animals each. Group I, [control group], Group II included rats which received intraperitoneal injection of 80 mg/ kg body weight aluminium hydroxide, 3 times per week for 2 months, Group III included rats which received aluminium hydroxide in the same dose, in addition the animals received 150 mg calcium carbonate daily orally for 2 months. At the end of experiment, the lung was excised and processed for both light and electron microscopic study. Light microscopic examination of [Group II] revealed focal exfoliation of the lining epithelium of the airway passages with cellular infiltration around the bronchi and in interstitium of the lung. Intraalveolar hemorrhage was observed as well as thickening of interalveolar septa. Excessive deposition of collagen fibers in the lung interstistium was noticed. Fragmentation and decrease of elastic fibers were seen. Apparent increase in the number of goblet cells in the wall of bronchi was detected. Electron microscopic examination of [group II] animals revealed the presence of numerous pneumocytes type II. Some of them had degenerated cytoplasm. The interalveolar septum showed great number of eosinophils and neutrophils together with collagen fibers deposition. Whereas, concomitant administration of calcium carbonate caused partial amelioration of aluminium induced lung toxicity