Generalized seizures alter the cerebral and peripheral metabolism of essential metals in mice

Abstract

The effects of seizures on the cerebral and peripheral metabolism of essential metals were studied in mice. Acute and chronic seizures were produced either by electroshock (ES) or by a systemic convulsant. Organ and subcellular distribution of 54Mn and 65Zn were determined prior to and at different intervals after seizure cessation. In mice shocked for 21 days, the concentrations of manganese, zinc, magnesium, and copper were determined in selected tissues. Sham-seizured mice served as controls. When 54Mn was injected after a single ES, the isotope's retention increased in the liver by 67% ( P < 0.01) and decreased in the brain and carcass by 53 and 42%, respectively ( P < 0.01). Repeated ES further augmented these effects ( P < 0.01). These changes diminished as a function of time to the animal's recovery from ES. Liver and regional brain fractionations revealed significant perturbation in the intercellular partition of 54Mn, suggesting increased metal utilization. Brain and liver 65Zn were not affected by ES. Manganese content increased in the liver by 67% ( P < 0.01) and decreased in whole brain by 16.5% ( P < 0.01), after chronic ES. Cortical manganese and hypothalamic magnesium were the principal sites of loss. Small (12 to 13%), but significant elevations of magnesium were found in liver and skeletal muscle ( P < 0.05). Copper increased in muscle by 26% ( P < 0.02). Seizures selectively altered the normal brain and extracerebral distribution of essential metals which may lead to regional metal deficiency or excess. These changes were linked to the metabolic consequences of convulsive activity and may be relevant to seizure control and electroshock therapy in man.