Ruriko Ninomiya

Relationship of cadmium accumulation to zinc or copper concentration in horse liver and kidney

The concentrations of Cd, Zn, Cu, and metallothionein (MT) in the liver, renal cortex, and renal medulla were determined in 24 male and 15 female younger thoroughbreds (age 27 to 97 months) and two old male horses (age 154 months and 190 months). High correlations were found between Zn and MT in the liver (partial correlation coefficient 0.836), between Cd and MT in the renal cortex (partial correlation coefficient 0.786), and between Cd and Zn in the renal cortex (partial correlation coefficient 0.675), while the correlation between Cd and MT in the liver was low (partial correlation coefficient 0.124). In the renal medulla, high correlations were found between Cd and Zn (partial correlation coefficient -0.631), between Zn and Cu (partial correlation coefficient 0.881), and between Cd and Cu (partial correlation coefficient 0.785). Therefore, in the liver, the MT concentration is the most highly correlated with the Zn concentration and is not correlated with the CD concentration unless artificially exposed to Cd. In the renal cortex, the MT and Cd concentrations are very highly correlated with each other. The Zn concentration is about 20 micrograms/g when the Cd concentration in the renal cortex is the lowest.

Concentrations of Cadmium, Zinc, Copper, Iron, and Metallothionein in Liver and Kidney of Nonhuman Primates

To evaluate the species specificity of Cd accumulation and the relationship of Cd with other essential metals and metallothionein (MT), the concentrations of Cd, Zn, Cu, and Fe in the liver and kidney and the MT concentrations in the soluble fractions of the liver and kidney were determined in Cd-uncontaminated nonhuman primates (11 species, 26 individuals) kept in a zoo and two wild-caught Japanese macaques. The compositions of metal-binding proteins in the soluble fractions were also investigated by high-performance liquid chromatography (HPLC). The hepatic Cd concentration was 0.03–14.0 µg/g and the renal Cd concentration was 0.35–99.0 µg/g, both varying greatly and being higher in nonhuman primates, which were more closely related to man. The hepatic Zn concentration was 24.0–176 µg/g and the renal Zn concentration was 13.5–138 µg/g, showing 7- to 10-fold differences, and a correlation (r=0.558, p<0.01) was found between renal Zn and renal Cd concentrations.It was proved that in the liver, MT is more closely correlated with Zn (r=0.795, p<0.001) than with Cd (r=0.492, p<0.01) and that in the kidney MT is correlated with both Cd (r=0.784, p<0.001) and Zn (r=0.742, p<0.001). HPLC analysis of metals bound to MT-like protein in chimpanzees, de Brazza’s monkeys, and Bolivian squirrel monkeys showed that more than 90% of Cd in both the liver and kidney, approx 40% of Zn in liver and 28–69% of Zn in kidney were bound to MT-like protein. The higher percentage Zn was bound to high-molecular protein.

Metal concentrations in the liver and kidney of aquatic mammals and penguins

We determined the hepatic and renal concentrations of Cd, Pb, Zn, Cu, and Fe in (1) marine mammals (three bottle-nosed dolphins, six California sea lions, and one sea otter), (2) freshwater and brackish-water mammals (one Oriental short-clawed otter and four European river otters), and (3) sea birds (three rock-hopper penguins, two king penguins, three Humboldt penguins, four Macaroni penguins, and four Magellanic penguins), all of which were kept in a zoo and an aquarium in Japan. We investigated the species-specificity of Cd accumulation in these aquatic animals. We also presented the basic data on metal concentrations. The concentrations of Cd in liver and kidney tended to be higher in marine mammals than in freshwater mammals. Many penguins, sea birds, showed high Cd concentrations. These results suggest that the habits of these animal species may be involved in accumulation of Cd. Pb concentrations were below the detection limit or low in both liver and kidney [not detected (ND)=0.132 µg/g and ND=0.183 µg/g, respectively]. The hepatic concentrations of Zn and Cu were high in young animals. In penguins, a positive correlation was found between the Zn and Cd concentrations in the liver and kidney and between the Cu and Cd concentrations in the liver. Individual variation was large in Fe concentration (48–3746 µg/g in the liver and 51–980 µg/g in the kidney).

Studies on transitory laxative effects of sorbitol and maltitol: II: Differences in laxative effects among various foods containing the sweetening agents

Abstract We studied the laxative effect of sweetening agents, hydrogenated glucose syrup (HGS) containing 88–92% maltitol, and sorbitol contained in various foods. The subjects were 89 volunteers (64 males and 25 females). Foods used in the study were tablets, bevarages, chewing gum, jelly, adzuki-bean jelly, chocolate and candies which contained one of the two sweetening agents. The doses of the sweetening agents were 0.4 g/kg for sweets in tablet form and 20 g for the other foods. Approximately 10% of the subjects exhibited diarrhea after taking tablets as a control; approximately 20% did so after taking HGS except for adzuki-bean jelly; and approximately 30% did so after taking sorbitol. There was no significant difference between HGS and the control substance. The incidence of diarrhea tended to be higher with the two sweetening agents only when contained in adzuki-bean jelly. The length of time between the ingestion of test substances and the first onset of diarrheal stool varied widely from less than one hour to 23 hours among individuals. However, adzuki-bean jelly diarrhea was induced within 5 hours in all subjects. Soft stool accounted for 60 – 90% of the macroscopic findings of diarrheal stool. Chief complaints of abdominal symptoms were gurgling, flatus and lower abdominal pain.

Relationship of metallothionein to cadmium and to zinc in human liver and kidney

We have studied the correlations between Metallothionein(MT) and heavymetals in various species. Human liver and kidney samples were measured for Cd, Zn, and MT concentrations. We found high correlations between Zn and MT in the liver(correlation coefficient 0.884), and between Cd and MT in the renal cortex(correlation coefficient 0.799), while we found low correlations between Cd and MT in the liver(correlation coefficient -0.043). This suggests that the essential metal Zn, which is necessary for growth may be related in humans to Cd accumulation with age through MT.

Itai-itai disease is not associated with polymorphisms of the estrogen receptor α gene

Abstract Itai-itai (or ouch-ouch) disease is a syndrome accompanied by bone mineral disorders, and which may be related to oral cadmium exposure. Itai-itai predominantly affects postmenopausal women with a history of multiple childbirths. Recently, it has been reported that polymorphisms of the estrogen receptor α (ERα) gene are associated with postmenopausal reduction of bone mineral density in Japanese women. However, estrogen receptors have never been studied in itai-itai disease. In this study, we examined the genotypic distributions of PvuII and XbaI restriction fragment length polymorphisms (RFLPs) of the ERα gene in patients with itai-itai disease and compared them with those of control subjects. The RFLPs are represented here as Pp (PvuII) and Xx (XbaI); the capital and small letters signify the absence and presence of restriction sites, respectively. The genotypic distributions of the patient group were: PP, 14.8%; Pp, 55.6%; pp, 29.6%; XX, 7.4%; Xx, 29.6%; and xx, 63.0%. These distributions were similar to those observed for the control groups, hence no pattern of genotypic distribution was observed that could be related to itai-itai disease. We conclude that RFLPs of the ERα gene may not be associated with itai-itai disease.

Dust concentration around the sites of demolition work after the Great Hanshin-Awaji Earthquake

The total dust concentration and the particle size distribution were determined around die sites of demolition associated with the Great Hanshin-Awaji Earthquake, which occurred on January 17, 1995. The total dust concentrations ranged from 0.20 to 0.23 mg/m3, being about 1.2 to 2.2 times that in die non-demolition area, and intermediate particles (2.1-11.0μm) made up a large proportion of the dust. The dust concentrations were not influenced by the weather on the day preceding measurement around the sites of demolition of concrete buildings, whereas the values decreased to about half around die sites of demolition of wooden buildings, nearly the same concentration in the control areas, when it had rained on the previous day. The dust concentrations increased compared with that in an average year but to The degree of die upper limit of die environmental standard (1 hr-value<0.20 mg/m3) . The dust due to the smoke of Mt. Sakurajima in the surrounding areas accounted for a higher proportion of large particles (<11.0>m) than in the earthquake-devastated area. The concentration of respirable dust (<;7.07>m) in a worker engaged in demolition was 4.0 mg/m3, being twice the recommended concentration (2 mg/m3) of the Japan Society for Occupational Health. It was thus considered that workers should use a respiratory protective device.

Studies on transitory laxative effects of sorbitol and maltitol: III: Alterations in serum contents due to laxative effects

Abstract Maltitol or sorbitol was administered in doses of 0.8 g/kg to 20 physically healthy subjects (10 males and 10 females) and 6 diabetic patients (3 males and 3 females). Maltitol and sorbitol caused diarrhea in 75% and 95% of the subjects, respectively. Stool was watery in most of the subjects. The serum concentration of each sweetening agent was as low as approximately 0.3 mg/dl 2 hours after administration. The serum concentrations of Na, K, Cl, BUN, glucose and insulin did not change 2 hours after administration.

Effect of cadmium administration and aging on the concentration of essential metals in liver and kidney

To investigate the changes in the concentration of essential metals in organs caused by exposure to cadmium (Cd) and by aging, Cd was administered subcutaneously in single doses of 0.3, 0.9 and 2.7 nig/kg to female rats 10 and 40 weeks of age. The animals were sacrificed on the 7th day after the administration. The concentration of Cd, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in the liver and the kidney was determined and the relations between the concentration of Cd and that of other metals were investigated.1) In 10-week-old rats, the amount of Cd accumulated in the liver and the kidney increased linearly with increasing doses of Cd, while in 40-week-old rats, suppressed accumulation of Cd in the liver and increased accumulation of Cd in the kidney were found after administration of the high dose.2) The concentration of Zn in the liver and the kidney both increased with increasing doses of Cd. There was no age-related difference.3) The concentration of Cu in the liver increased in the animals which received the intermediate and the high dose, irrespective of age. The concentration of Cu in the kidney showed no changes caused by Cd administration or by aging.4) The concentration of Fe in the liver increased in both 10-week-old and 40-week-old rats which received the high dose. The concentration was higher in 40-week-old rats than in 10-week-old rats. The Fe concentration in the kidney and the Mn concentration in the liver and the kidney was not affected by Cd administration or by aging.5) Discriminant analysis, by age, suggested that the amount of metals in the liver and the kidney was more likely to be affected by exposure to Cd in young individuals and less likely to be affected by exposure to Cd with the increase of age.

Effect of dietary protein on the distribution of cadmium, zinc and copper in rats following the oral administration of cadmium

Abstract Cadmium, 100 μg/rat/day, was administered orally 100 times (total amount of Cd administered, 10 mg), under conditions of low protein intake. The total amount of Cd in the liver and kidneys was as follows: females fed 20% protein diets > females fed 5% protein diets > males fed 20% protein diets ≒ males fed 5% protein diets. A decreased Zn concentration was found in the liver of males and the pancreas of males and females fed with the 5% protein diet. The Cu concentration in the kidneys was markedly influenced by low protein intake.