Alternate cadmium exposure differentially affects amino acid metabolism within the hypothalamus, median eminence, striatum and prefrontal cortex of male rats

This work was designed to analyze the possible changes in glutamate, aspart ate and glutamine content induced by cadmium exposure in the hypothalamus, striatum and prefrontal cortex of rats, using an alternate schedule of meta l administration. Pubertal-adult differences were also evaluated. In adult control rats, glutamate and aspartate contents in the anterior hypothalamus decreased as compared to pubertal controls. After cadmium administration f rom day 30 to 60 of life, the content of anterior hypothalamic glutamate an d aspartate diminished. In adult control animals, the glutamine content inc reased in mediobasal hypothalamus as compared to pubertal controls. After c admium exposure from day 30 to 60 of life, the mediobasal glutamine content increased, and after cadmium treatment from day 60 to 90 of life, the medi obasal aspartate content decreased. In adult control rats the content of gl utamine, glutamate and aspartate of the posterior hypothalamus decreased si gnificantly. After cadmium administration in pubertal animals, posterior hy pothalamic contents of glutamine, glutamate and aspartate diminished. Cadmi um treatment of adult animals caused a decrease in glutamine content, as co mpared to controls. In adult control rats, only glutamate and aspartate con tent increased in the prefrontal cortex as compared to the values found in pubertal controls. When cadmium was administered to adult animals, only the aspartate content decreased. In the striatum, cadmium decreased the glutam ine and aspartate contents when administered from day 60 to 90 of life. The se data suggest that cadmium differentially affects amino acid metabolism i n the hypothalamus, striatum and prefrontal cortex. Age-dependent effects o f cadmium on these brain areas appeared to have occurred. (C) 2001 Elsevier Science Ltd. All rights reserved.