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Biomedical subjects

K Tomokuni

Publications and source records attributed to K Tomokuni.

At least 73 records · Page 4Linked to original sources
PubMed1986

Simple liquid-chromatographic determination of urinary coproporphyrin in workers exposed to lead.

We developed a simple method for the determination of urinary coproporphyrin (CP) in lead workers, using a "high-performance" liquid chromatograph (HPLC) equipped with a fluorescence detector. The detection limit of urinary CP in this method was 5 micrograms per liter of urine. The working linear range of urinary CP concentration was 5 to 1500 micrograms/L. In 41 lead-exposed workers, the urinary CP values obtained by the present HPLC method were well correlated with those obtained by a conventional spectrophotometric method (r = 0.94). The present method is useful for screening workers exposed to lead.

Coproporphyrins↗
PubMed1986

Factors affecting determination of delta-aminolevulinate by use of Ehrlich's reagent.

We investigated the formation of delta-aminolevulinic acid (ALA)-pyrrole and subsequent color development used in determining ALA in urine. Of three condensation reagents examined--acetylacetone, ethyl acetoacetate, and methyl acetoacetate--the last was the best. When the ALA-pyrrole is reacted with Ehrlich's reagent in ethyl acetate according to one procedure, the optimum concentration of perchloric acid in the reagent is 0.5 to 1.0 mol/L. Its optimum concentration is 1.0 to 2.3 mol/L when the reaction takes place in water.

Aminolevulinic Acid↗
PubMed1985

The tissue distribution of diazinon and the inhibition of blood cholinesterase activities in rats and mice receiving a single intraperitoneal dose of diazinon.

The tissue distribution of diazinon and the inhibition of cholinesterase (ChE) activities in plasma, erythrocyte and brain were investigated using male rats and mice which received a single intraperitoneal (i.p.) dose of diazinon (20 or 100 mg/kg body wt) in olive oil. The blood diazinon level was estimated to reach a maximum at 1-2 h after the i.p. administration. It was demonstrated that the diazinon residue levels are the highest in the kidney, when comparing the distribution of diazinon among liver, kidney and brain in the animals after dosing. It was indicated that the ChE inhibition by diazinon exposure is greater in the plasma than in the erythrocytes for male mice, while its inhibition is greater in the erythrocytes for male rats. Brain ChE activity was also inhibited markedly in the mice after dosing.

Animals↗
PubMed1985

Diazinon concentrations and blood cholinesterase activities in rats exposed to diazinon.

The tissue distribution of diazinon and the inhibition of blood cholinesterase (ChE) activity were investigated in male rats which received a single intraperitoneal (i.p.) dose of diazinon (100 mg/kg body wt) in olive oil. Diazinon concentration in the blood reached a maximum 1-2 h after dosing. Comparing the distribution of diazinon among liver, kidney and brain in treated rats, the diazinon residue was much greater in the kidney than in other organs, being 500 times that in the liver and 11 times that in the brain at 8 h after dosing. Erythrocyte and plasma ChE activities were inhibited rapidly, but ChE inhibition was greater in the erythrocytes than in plasma.

Animals↗
PubMed1981

Relationship between lead concentration in blood and the activities of erythrocyte pyrimidine 5'-nucleotidase and delta-aminolevulinate dehydratase in the mice exposed to lead.

The relationship between the activities of both pyrimidine 5'-nucleotidase (Py5N) and delta-aminolevulinate dehydratase (ALA-D) in erythrocytes and the concentration of lead in blood was investigated in the mice which were given ad libitum a drinking water containing lead of 10 to 500 ppm, for 30 days. From these results, it was demonstrated that the erythrocyte Py5N activity is inhibited by lead and its activity level is negatively correlated with the concentration of lead in blood (r = -0.78). In addition, it was suggested that the erythrocyte Py5N activity is a better indicator in the exposure to relatively high lead concentration while the ALA-D is a more sensitive indicator for evaluating the lead exposure of low and moderate levels.

5'-Nucleotidase↗
PubMed1980

Comparative study of effects of lead on the activity of erythrocyte pyrimidine 5'-nucleotidase and delta-aminolevulinate dehydratase in vivo and in vitro.

The effect of lead on the activities of erythrocyte pyrimidine 5'-nucleotidase (Py5N) and delta-aminolevulinate dehydratase (ALA-D) was studied in the mice which were given ad libitum a drinking water containing lead of 10, 50 and 250 ppm, for 27 days. The erythrocyte Py5N activity was not decreased in all groups of lead-exposed mice. However, the erythrocyte ALA-D activity was markedly decreased in the groups exposed to 50 and 250 ppm lead. These data indicate that erythrocyte ALA-D is more sensitive than Py5N to lead in vivo. On the other hand, from the in vitro study, it was demonstrated that the human erythrocyte Py5N is moderately inhibited by zinc and tin, and markedly by mercury, cadmium, silver, copper, and lead, at 10(-4) molar concentrations. In addition, it was observed that the erythrocyte Py5N is most remarkably inhibited by mercury while the ALA-D by lead, among metals tested.

5'-Nucleotidase↗