ISSN:
1573-6903
Keywords:
Manganese
;
cations
;
neurons
;
superoxide
;
dismutase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Mg2+, Ca2+, Mn2+, Zn2+, and Cu content of neurons from chick embryo cortex cultivated in chemically defined serum free growth medium was determined by energy dispersive X-ray fluorescence and atomic absorption spectroscopy. The intracellular volume of cultured neurons was determined to be 2.73 μl/mg. Intracellular Mn2+, Fe2+, Zn2+, and Cu2+ in the cultivated neurons were 100–200 times the concentrations in the growth medium: Mg2+ and Ca2+ were 0.9 and 1.7 mM respectively, around 20 fold higher than in growth medium. Mg2+, Fe2+, Cu2+ and Zn2+ concentrations in neurons were in the range of ca. 300–600 μM, approximately 2–3 times the values previously reported in glial cells; Ca2+ and Mn2+ content of the neurons were higher by 5 and 10 fold respectively compared to glial cells. In neurons, the subcellular distribution of Fe2+, Cu2+, and Mn2+ follows the rank order: cytosol〉microsomes〉mitochondria; for Zn2+ the distribution differs as following: cytosol 〉mitochondria〉microsomes. Determination of the superoxide dismutase activities in the cultivated neurons indicated that the Mn2+ linked activity predominates whereas, the Cu-Zn dependent enzyme is dominant in glial cells. Enrichment of the culture medium with Mn2+ to 2.5 μM enhanced the Mn-SOD by approximately 33% but Cu2+−Zn2+ enzyme activity was not modified. The high Mn2+ content, the capacity to accumulate Mn2+, and the predominancy of the Mn−SOD form observed in neurons is in accord with a fundamental functional role for this metal ion in this type of brain cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00971634
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