Brain Manganese Accumulation is Inversely Related to GABA Uptake in Male and Female Rats

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Keith M. Erikson, Associate Professor and Director of Graduate Studies (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Iron (Fe) is an essential trace metal involved in numerous cellular processes. Iron deficiency (ID) is reported as the most prevalent nutritional problem worldwide. Increasing evidence suggests that ID is associated with altered neurotransmitter metabolism and a risk factor for manganese (Mn) neurotoxicity. Though recent studies have established differences in which the female brain responds to ID-related neurochemical alterations versus the male brain, little is known about the interactions of dietary ID, Mn exposure, and sex on ?-amino butyric acid (GABA). Male and female Sprague-Dawley rats were randomly divided into four dietary treatment groups: control (CN), control/ Mn supplemented, ID, and ID/Mn supplemented. After 6 weeks of treatment, both ID diets caused a highly significant decrease in Fe concentrations across all brain regions compared to CN in both sexes. Both ID and Mn supplementation led to significant accumulation of Mn across all brain regions in both sexes. There was no main effect of sex on Fe or Mn accumulation. Striatal synaptosomes were utilized to examine the effect of dietary intervention on 3H-GABA uptake. At 4 weeks, there was a significant correlation between Fe concentration and 3H-GABA uptake in male rats (p < 0.05). At 6 weeks, there was a significant inverse correlation between Mn concentration and 3H-GABA uptake in male and female rats and a positive correlation between Fe concentration and 3H-GABA uptake in female rats (p < 0.05). In conclusion, ID-associated Mn accumulation is similar in both sexes, with Mn levels affecting GABA uptake in both sexes in a comparable fashion.

Additional Information

Publication
Toxicological Sciences 95(1): 188-195
Language: English
Date: 2007
Keywords
GABA, iron deficiency, manganese, rat, neurotoxicity

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