Satoru Miyata

Increased manganese level in spinal cords of amyotrophic lateral sclerosis determined by radiochemical neutron activation analysis.

The manganese distribution in the cross-section of the cervical, thoracic and lumbar portion of the spinal cords from 7 autopsied cases with amyotrophic lateral sclerosis (ALS) and 6 control subjects were determined by radiochemical neutron activation analysis. It was possible to determine 1 ng levels of manganese content accurately in the small tissues about 1 mg of dried weight using wet ashing and chemical separation after neutron activation. The dried weight of spinal cord was about 1/3 of the wet weight. Manganese concentration in the wet tissue was calculated from the ratio of dried to wet weight. In the anterior horn of the cervical cords of ALS, manganese concentration was the highest; 1.75 +/- 0.39 ng/mg of dried weight and 0.59 +/- 0.09 ng/mg of wet weight, respectively. These were significantly higher (P less than 0.01) compared to those in controls; 1.02 +/- 0.12 ng/mg of dried weight and 0.35 +/- 0.04 ng/mg of wet weight, respectively. The elevation of manganese level in the spinal cords of ALS was more prominent in the anterior horn and lateral column than in the posterior column both in dried and wet tissues. Since manganese inhibits neuronal transmission, it is likely that neurological degenerative changes occur as a result of local disturbances of manganese metabolism in the spinal cord of ALS.

Heavy metal concentrations in blood cells in patients with amyotrophic lateral sclerosis

Manganese (Mn) and selenium (Se) concentrations in blood cells were measured by neutron activation analysis. Blood was obtained from patients with amyotrophic lateral sclerosis (ALS), patients with other neurological diseases and control subjects. Dried blood cells were activated by neutron irradiation. Mn was determined after chemical separation and Se was determined nondestructively. Mn concentrations in blood cells from ALS patients were significantly lower (P less than 0.01) than those from the other groups. The Mn concentrations were also significantly lower (P less than 0.01) in late than in earlier stages of ALS. Se concentrations in blood cells from ALS patients were significantly higher (P less than 0.01) than those from the other two groups. A generalized abnormal distribution of these metals may play a role in the pathogenesis of this disorder. Bromine, zinc, rubidium, and iron concentrations of erythrocytes were the same in all groups.

Dopamine-β-hydroxylase activities in serum and cerebrospinal fluid of aged and demented patients

Age-related changes in dopamine-beta-hydroxylase (DBH) activities in serum and cerebrospinal fluid (CSF) were determined. In normal subjects, serum DBH activity increased gradually from the 3rd to the 8th decade, but decreased prominently in the 9th decade. DBH activity in CSF did not differ between younger and older subjects. Serum DBH activity decreased significantly in senile dementia of Alzheimers type (SDAT, 12.2 +/- 8.8 nmoles/min/ml, P less than 0.05), but not in multi-infarct dementia (MID, 13.9 +/- 9.1 nmoles/min/ml) compared to control subjects (17.1 +/- 9.5 nmoles/min/ml). The decrease of serum DBH in SDAT was more prominent in patients with severe dementia and/or severe brain atrophy. DBH activity in CSF was much lower than that in serum and did not correlate with each other. DBH activity in CSF obtained from SDAT patients (1.60 +/- 0.94 nmoles/h/ml) and from MID patients 2.01 +/- 0.99 nmoles/h/ml) were both lower than that from other neurological diseases without dementia (4.04 +/- 3.81 nmoles/h/ml). DBH in CSF from SDAT patients was significantly lower (P less than 0.05) than that from controls, but that from MID did not differ from controls. Noradrenergic nervous dysfunction is partly associated with pathophysiology and life expectancy of senile dementia of Alzheimers type (SDAT).

Determination of manganese in tissues by neutron activation analysis using an antimony pentoxide column

A rapid and accurate method is presented for the determination of manganese in biological samples, using neutron activation analysis. Biological samples were irradiated at 5000 kW for 30 min. The samples were ashed on a hot plate with 14 mol/l HNO3 and 6 mol/l HClO4, and resolved in 1 mol/l HClO4. 24Na and 24K were removed by passing each sample through in antimony pentoxide column. 54Mn was added as a tracer to calculate the ratio of manganese recovered by the separation procedure. Recovery was over 90%. This method was applied in order to determine manganese in various tissues. In the cervical spinal cord of the controls, the mean manganese concentrations in the anterior horn, the lateral and the posterior columns were 1.14, 1.06 and 0.90 ng/mg of dried tissue, respectively. In two cases if amyotrophic lateral sclerosis the manganese concentrations in the cervical spinal cord were elevated, particularly in the anterior horn and the lateral column.

Metal contents in duodenal aspirates of normal subjects during pancreozymin-secretin test

SummaryThe calcium, magnesium, zinc, copper and manganese concentrations in the duodenal aspirates obtained during pancreozymin-secretin tests were measured in 16 normal subjects. Total outputs of calcium, magnesium, zinc, copper and manganese during the 70 minute period (10 minutes after pancreozymin injection and 60 minutes after secretin injection) were 4.91 ± 3.47 mg, 1.88±0.96mg, 180±42Μg, 162 ± 104Μg and 16.9 ± 14.2Μg (mean ± S.D.), respectively. The concentrations of metals were the highest in P fraction (during 10 minutes after pancreozymin injection) and the lowest in S3 fraction (during the 20–40 minute period after secretin injection). Although calcium, magnesium, copper and manganese concentrations varied widely from case to case especially in P fraction, zinc concentration exhibited comparatively small variation in every fraction.Magnesium, copper and manganese concentrations exhibited significant correlations with icterus indicies of the aspirates. Zinc and magnesium concentrations correlated with amylase activity and magnesium concentration exhibited an inverse relation to bicarbonate concentration. Most metal concentrations correlated well each other, but there were no correlations between zinc and calcium and between zinc and manganese concentrations. Zinc seemed to be excreted mainly with pancreatic juice and copper and manganese mainly with bile.