Severe iron deficiency and manganese concentrations in the rat cerebrum

Abstract

Severe iron deficiency is known to increase brain manganese concentration in rats. We studied whether severe iron deficiency affects dose‐effect relationship between dietary manganese and brain manganese in rats. Forty‐eight weaning male Wistar rats were equally divided into 8 groups and fed on respective experimental diets for 7 weeks. Four diets were iron‐deficient diet containing graded levels of manganese: one times, 3 times, 6 times and 9 times the National Research Council manganese requirement. The other four diets were iron‐adequate diet containing the graded levels of manganese as same as the above. After dietary regimen and 16 hour starvation, rat cerebrum was separated into striate, hippocampus and cortex (i.e., remaining parts). Samples were decomposed by wet ashing using nitric acid followed by hydrogen peroxide. Manganese concentration was measured by inductively coupled plasma‐mass spectrometry. Data were analyzed by simple linear regression, general linear model and nonlinear regression. The model that gave the highest Akaike information criterion was selected. Except for hippocampal manganese concentration in iron‐adequate rats, manganese concentrations in the measured brain regions were significantly and positively correlated with dietary manganese level. For hippocampus and striate, a general linear model was selected. Iron deficiency and dietary manganese independently and significantly increased manganese level in striate. In hippocampus, iron deficiency significantly increased manganese concentration. Effect of dietary manganese was significant when animals were iron‐deficient. Exponential saturation model regarding dietary manganese was selected for cortex. Effect of dietary manganese was significant and iron deficiency increased the curve span approximately by two‐fold. These results suggest that severe iron deficiency augments increments of manganese level by dietary manganese in the rat brain region.Support or Funding InformationThis work was supported by JSPS KAKENHI Grant Numbers JP17K00877 and JP 25350137.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.