Objective: To study the effects of chronic triochloride aluminum (AlCl3) exposure on both histocytological changes and amyloid precursor protein 695 (APP695) mRNA expression level of the rat spinal cord, in order to evaluate the relationship of the histocytological changes and the APP695 mRNA level in rat spinal cord exposed chronicly AlCl3.
Methods: Twenty six-month-old SD female rats were randomly divided into 2 groups, group normal and group exposed. The rats were exposed with intraperitoneal injection of 1 ml AlCl3 solution for continuous 3 days of the interval of one day during the period of total 72 days. Behaviors of the rats were observed by naked eyes. Histocytological examinations of the spinal cords of the rats were performed with HE dyeing. The expression levels of APP695 mRNA of spinal cords were tested with RT-PCR.
Results: In comparition with group normal, intraperitoneal injection of AlCl3 solution caused movement obstacle of rat hind legs for short time. In comparition with normal group in the spinal cord cinerea of exposure group, invasion of glial cells into motor neuron appeared, satellite phenomenon appeared, glial cells prominently increased in number, traverse neurofibers prominently increased both in number and marking, glial cells around the blood vessels prominently increased in number, vacuoles prominently increased in number, expressions of APP695 mRNA prominently increased.
Conclusion: Intraperitoneal injection of AlCl3 solution could cause movement obstacle of rat hind legs for short time. Chronic aluminum exposure could cause injury or death of neurons, induced increases of glial cells, and vacuolar degeneration in rat spinal cords. Super expression of APP695 mRNA could participate the neuronal injury course.