Requirements by animals and humans for dietary trace nutrients are often modified by interactions with other nutrients, with nonnutritive food components, with food additives and drugs, with environmental contaminants such as agricultural or industrial chemicals, and with natural xenobiotics such as mold toxins and toxicants in plants. Some selected examples of these interactions are reviewed briefly to illustrate various types of nutrient x xenobiotics interactions. For example, Zn requirements are increased by excessive dietary Ca, Cu or Fe, by dietary phytate, oxalate or (soluble) silicate, by Cd or Ga, by certain types of dietary fiber, and by ingestion of some kinds of clay. Certain types of mycotoxicoses (e.g., sporedesmin) and toxicoses caused by plant toxicants have been treated and even prevented by pharmacological levels of Zn. In ruminants, siliceous forages ingested contribute to soluble siliceous materials in rumen fluid that bind to Cu, Mn and Zn, thereby decreasing their bioavailability in the lower gastrointestinal tract. Deficiencies of Zn and other trace elements have been elicited by prolonged, unsupplemented total parenteral nutrition and by massive supplements of Fe. An increasing volume of biomedical literature has documented alterations in porphyrin biochemistry and metabolism associated with relatively low-level exposures to dietary and environmental toxicants and xenobiotics, including the trace elements Pb, As, Ga, Mn, Co, Ni and Cu. Some nutrient x toxicant interactions pose negative effects or overt adversity from nutritional supplementation that otherwise would be regarded as totally beneficial, e.g., Fe overload exacerbates the porphyria induced by dioxin, and Fe deficiency lends protection. Similarly, Zn supplementation exacerbated hyperbilirubinemia and other manifestations of hepatotoxicity in sheep caused by toxicants in the plant Kochia scoparia. Recently researchers at the University of Illinois caused As toxicosis in animals by providing excessive cysteine or ascorbic acid in diets containing normally used levels of arsenical compounds widely used as feed additives for swine and poultry. The levels of dietary Se that lead to symptoms of deficiency or of toxicity may be modified greatly by interactions with other nutrients or xenobiotics. Adequacy or inadequacy of trace element nutrients may be altered by xenobiotics in beverages such as tea, or by pharmaceuticals such as cimetidine or even non-prescription antacids. containing soluble aluminum. Whether boron is a required nutrient or merely interacts with nutrients to provide benefits is a topic of current interest. Both requirements and tolerances of trace elements are modified by interactions with other nutrients and xenobiotics. Research to elucidate these interactions promises to improve animal and human health and to increase productivity of livestock.

In 1952, Yahito Kotake and T. Inada have found the diabetogenic symptoms in V. B₆ deficient rat.

In 1985, R. Tsubouchi reported that the kidney calcium increased in V. B₆ deficient rat.

From recent research, the increase of kidney calcium uptake in V. B₆ deficient rat have found and suggested that the renal calculi was correlated with the change of calcium metabolism, such as the decreased calcium reabsorption in renal proximal tubles.

And it might be suppressed the calcium deposit by V. B₆ administration.

Stress is a condition in which strain appears in the body due to some external stimulus inflicted on the body. The external stimulus is called the stressor and produces an abnormality of homeostasis in the living body. Stress participates in both the genesis of arteriosclerosis and changes in the calcium dynamic in the body. A study investigating the effect of calcium administration on stress and arteriosclerosis was perfomed.

In this experiment, six-week old male Wistar rats were for six weeks with a calcium-supplementaled feed. After this phase, restraint stress was applied for 12 hours and a macroscopic study was performed in organs and blood components.

The results of this study disclose an inhibition of the serum aldosterone rise in the calcium administration group and blood cell serotonin decrease which is usually seen in response to restraint stress. However, the difference in serum calcium was small. Atrophy of the thymus and spleen was inhibited in the calcium administration group as compared with controls. This preliminary data appears to demons- trate an effect of calcium administration on the physiologic stress response.

The effect of acute magnesium deficiency on polymorphonuclear leukocytes function in rats was examined. The symptom of magnesium deficiency such as hyperemia of ears was found in magnesium deficient rats by the 4th to 5th day of the regimen. The body weight of magnesium deficient rats was significantly lower than that of control on the 10th day. The numbers of total WBC, neutrophiles and eosinophiles in magnesium deficient rats was remarkably increased on the 10th day. The released activities and total activities of both lysosomal enzymes, β-glucuronidase and myeloperoxidase, in magnesium deficient rats were significantly increased from the 7th day. The production of superoxide anion in magnesium deficient rats was also increased from the 7th day of the regimen. However, no significant difference in fMet-Leu-Phe stimulated chemotaxis of PMN was observed between deficient and control rats. These results suggest that the cytotoxicity mediated by polymorphonuclear leukocytes was significantly increased in magnesium deficient rats.

It is considered that hypogeusia occurs from the deprivation of zinc contained in receptors existing in taste buds of tongue by various metabolic chelators. Needless to say, one of the reasons on the problem is the decrease of zinc intake as nutrient. The restorative therapy of teeth with zinc alloy will be to affect easily the acuity of taste on the zinc deficient patients. If zinc is used for the therapy, corrosive dissolution of zinc metal is supposed to occur at first.

Secondarily dissolution by galvanization due to a potential difference is supposed, On the study of metallic dissolution in intra-oral cavity one must consider the effect of-dl-lactic acid, the product by Lactobacillus acidophilus and further the effect of acidification of buffer substance, solium monohydrogen phosphate in saliva.

The dissolution of zinc metal into various mediums receive restrictive or promotive effect according to the nature of the produced salts, So the dissolution does not proceed to one side.

Therefor, zinc metal does not dissolve easily, but the possibility to improve the taste acuity by zinc yet remains.

Raw oyster which contains various minerals such as zinc was extracted with hot water (80°C) and separated by gelfiltration (Sephadex G-50) to obtain the low molecular weight fraction. Zinc containing fraction was separated into two parts, one part was eluted at void volume and another part was eluted below about M. W. 2000.

Zinc in this fraction migrated less than Zinc²⁺ of zincsulfate. Then low molecular weight ・fraction was rechromatographed with Toyopearl HW-40 F. Amino acids, Ninhydrin reaction and ultra-violet absorption of this fraction were analyzed. Taurine, Pro, Gly, Ala were detected mainly in this fraction. Zinc in low molecular weight fraction was separated into three fractions. Main fracion of zinc was eluted at the same place where UV positive fraction was eluted. This UV positive fraction was purified by Dowex ion exchange chromatography. It was speculated Homarine with infrared spectrum and UV spectrum. The mixture of taurine and zincsulfate was also examined. It was separated by Sephadex G-10. Zinc in this mixture was eluted at the same place where zincsulfate was solely separated by Sephadex G-10.

The influences of iron deficiency to the tissue trace element levels (iron, zinc, copper and manganese) in rats were investigated. Seven rats were fed by control diet (iron concentration 128μg/g) and another eight rats were fed by iron-deficient diet (iron concentration 5.9μg/g) with double-distilled water for 21 days. Trace element levels in whole blood and tissues were determined by atomic absorption spectrometry. The hematological data of iron-deficient rats indicated severe anemia. The iron concentrations of blood and all tissues determined in iron-defocient rats were siginificantly decreased than those of control rats. The zinc level of blood in iron-deficient rats was significantly lower than control rats. The copper concentrations of blood, liver, spleen and tibia of iron-deficient rats were significantly decreased than those of control rats, but that of femoral muscle was significantly increased. The manganese levels of brain, heart, spleen, testis, femoral muscle and tibia in iron-deficient rats were significantly higher than control rats. It is suggested that iron deficiency affects trace element metabolism and particular consideration to trace element is necessary in the therapeutic use of total parenteral nutrition to patients with iron deficiency.

We investigated the difference of Mn concentration and distribution in rats administered perorally, intravenously and intraperitoneally for a week.

Forty two male Wistar rats were divided into eight groups A to H. Group A (n=5) and B (n=7) were maintained by synthetic diet including 50, 1000mg/kg. diet Mn, respectively. Group C (n=5),D (n=5)and E (n=5) were administered Mn intravenously with the dosage of 0.088, 0.88 and 2.2mg/kg. b. w./day, respectively. Group F (n=5), G (n=5)and H (n=5)were administered Mn intraperitoneally with the dosage of 0.088, 0.88 and 2.2mg/kg. b. w./day, respectively. Liver, bone, kidney, heart, spleen, testis and muscle were analyzed by atomic absorption spectrophotometry for Mn. The Mn concentrations in heart, spleen, testis and muscle were smaller than those in liver, bone and kidney. And they were hardly increased with increasing administration dosage. The Mn concentrations in bone and kidney were increased accompanied with administration dosages, particulary the Mn concentrations of C, D and E groups in bone were increased proportionally to administered Mn dosage. In most tissues, the Mn concentrations at group B were as same as group C or F. However, in liver, the Mn concentration at group B was the highest of all the groups. Therefore, we ascertained that liver played an important role in Mn homeostasis.

A study was made on the trace element concentration in black dust deposited in human lungs which were considered to have been inhaled through air and then intaked into the body. Autopsied lung samples were used for this study. Deposited particulates were separated in dissolving with alkaline solution and were prepared by multiple cycles of ultra-high speed centrifugation. The final residue was then washed using water and acetone and finally dried. The resulting black powder was analyzed using a scanning electron microscope coupled with an X-ray microanalyzer and by neutron activation analysis. In result, Al, Ti, V, Mn, Fe, Zn, Mg, Si and other elements were determined quantitatively and qualitatively. An attempt was made to correlate to contents of several elements with age. Correlation coefficients of V, Al, Fe, Si were positive on 72 samples. On the contrary, that of Mn and Ti were not correlated. This result means that absorption and clearance of Mn into body were considered to be fast. For emphasis of this result, lung tissues with deposited particulate was analyzed by ICP method. The result showed a same tendency on the correlation between accumulated amount of trace element and age in inhaled particulate deposited into lung tissue. These results provided us a valuable information about intake of trace nutrient through inhaled particulates into body.

The object of this study was to clarify trace element cycling on soli-feed-dairy cattle in the standard model of dairy farm in Japan. Except for Fe, trace elements ingestion from purchased feed of the cow herd were generally larger than that from self-sufficing feed. Since the secretions into milk and body accumulation of trace elements were remarkably smaller than those ingestion, trace elements excretion were almost the same as those ingestion. Thus, large amounts of trace elements were accumulated in the soil from the out 6f the model of dairy farm.

Previously we reported that hemolysis of erythrocytes, induced in vitro by tert-butyl hydroperoxide (t-BuOOH), was greater for erythrocytes from Se-deficient than from Se-adequate rats. Neither exogenous glutathione (GSH) nor endogenous α-tocopherol suppressed the t-BuOOH-induced hemolysis. Here, we report recovered resistance to hemolysis by erythrocytes from rats initially made Se-deficient (18 mo) and subsequently repleted with sodium selenite for 12 wk. Freshly isolated erythrocytes were incubated with 0.6 mM t-BuOOH in isotonic saline-phosphate (pH 7.4) with 1mM NaN₃, 1mM KCN and 2 mM GSH for 2 h 37°C. Hemolysis of erythrocytes from Se-deficient/repleted rats was 95% after 3 wk, 14% after 5 wk and 5% after 7 wk Se repletion, and glutathione peroxidase (GSH-Px) activities were 9% of normal at 3 wk, 19% at 5 wk and 26% at 7 wk. Pyruvate kinase (PK) activity was elevated during Se deficiency and returned to normal in Se”repleted (12 wk) rats.

Blood selenium level in Japanese chronic alcoholics was determined fluorometrically. Two groups were studied. One group consisted of 26 male chronic alcoholics (mean age of 45 yr. with a range of 26- 58 yr.) without severe malnutrition or hepatic dysfunction. They had, at least, 10 year-history of alcohol abuse at 1.8L Sake/ day. Another group consisted of 17 heathy male controls (mean age of 44 yr. with a range of 17-61 yr.) without significant history of ethanol abuse. Serum and red blood cell selenium levels were measured on the day of admission, one week and one month after admission, respectively. Serum selenium levels in the alcoholics did not differ significantly from the controls throughout the observation period (0.112 μg/ml on admission in alcoholics vs. 0.117 in control). Red blood cell selenium level in- creased significantly in the alcoholics (0.838 μg/gHb in alcoholics vs. 0. 728 in control). The increased erythrocytes selenium level may suggest a significant role of selenium in chronic alcoholics.

Metallothioneins (MTs) are cysteine-rich proteins with low molecular weight, and bind with metal ions such as Cd, Zn, Hg, and Cu. All cysteinyl residues are involved in metal binding. N. crassa Cu-MT is the smallest MT found so far. It consists of only 25 amino acids and binds 6 Cu ions to 7 cysteinyl residues. We are interested in examining whether the structure and properties of N. criαssa MT are influenced by substituting selenium atoms for the sulfur ones. Thus, we have studied a synthetic method for a selenium-containing MT (selenometallothionein, SeMT), in which all the cysteinyl residues are replaced by selenocysteine residues, and its properties in comparison with those of MT synthesized in a similar manner.

SeMT was synthesized by the Merrifield method. Se-(pMethylbenzyl)-N-t-Boc-selenocysteinewas synthesized from selenocystine, which was prepared from disodium diselenide and β-chloroalanine described previously. MT was also synthesized in a similar manner. Both synthesized peptides were identified by amino acid analysis. Cu-SeMT prepared with Cu²⁺ contained 3g-atoms of Cu per mol of the peptide. The absorption spectrum of the Cu-SeMT was characterized by a very broad band displaying a shoulder around 270 nm.

Selenium (Se) concentrations in whole blood and plasma in pregnant rats were significantly lower compared to non-pregnant control. (p<0.01)Similarly Glutathione Peroxidase (GSHPx) activities in plasma of pregnant rats were significantly lower than in non-pregnant control. (p<0.01)In the red blood cell (RBC), Se contents and GSHPx activities remained unchanged during pregnancy. The Se concentrations of bone in pregnant rats were significantly lower than in non-pregnant control. (p<0.05) A positive correlation existed between RBC GSHPx activity and RBC Se concentration in the rats. (p<0.001).

The postnatal changes of selenium (Se). zinc (Zn), copper (Cu) and taurine in human milk, and its relation to growth were examined. The samples were collected from 239 healthy women, from days 3 to 215 postpartum.

The Se, Zn, Cu and taurine concentrations in human milk decreased with postnatal days. The Se concentrations (mean and SD) from days 3 to 7 postpartum (stage 1). from 8 to 30 (stage 2). from 31 to 150 ( stage 3) and over 151 days ( stage 4) were 27±8, 22±6, 15±4, and 18±12ng/ml, respectively. The Zn concentrations from stage 1 to 4 was 4.6±2.5, 3.2±0.4, 1.1±0.6, and 0.8±0.7μg/ml. respectively. The Cu concentrations were 0.29±0.18 for stage 1 and 2, 0.22±0.06 for stage 3, and 0.18±0.09 for stage 4, respectively. The taurine concentrations from stage 1 to 4 were 0.59±0.21, 0.46±0.20, 0.22±0.59, and 0.18±0.09 μmoles/ml, respectively.

After the human milk samples were divided into high (over mean +0.68σ ,about 25% of the population) and low (below mean -0.68σ ) concentration groups with regard to each nutrient examined, significant relationships were observed between body weight and concentrations of copper and taurine in human milk.

Although there were reports that vanadium (V) plays some role in bone formation, its relation to the ossification is not clear now. For this reason, we were interested to study the nutritional role of V, and investigated the distribution of vanadium-48 (⁴⁸V) in rats and their bones in comparison to that of phosphorus-32 (³²P). In whole-body autoradiograms of Wistar rats injected with ⁴⁸V and ³²P, ⁴⁸V was uptaked in all bones as well as ³²P. ⁴⁸V and ³²P were uptaked in bone of Wistar rats more than that of ODS rats (these rats having an osteogenic命 disorder).The autoradiograms of the femur in Wistar and ODS rats showed that both nuclids were distributed in the epiphysis. These results suggested that V particpated in ossification through the same mechanism as P.

We also synthesized [⁴⁸V] vanadyl pheophorbide chelate (⁴⁸V(IV)O-Pheo) and examined it to apply as a useful positron radiopharmaceutical for tumor diagnosis, since ⁴⁸V emitted positron and pheophorbide had photodynamic actions and an affinity to tumors. At 24h after injection, high uptake of ⁴⁸V(IV)O-Pheo was observed in FM3A, MH 134 and S 180 tumors. In the autoradiograms of mice bearing FM3A tumor, ⁴⁸V(IV)O-Pheo showed the image of tumor most distinctly at 24h when compared with other ⁴⁸V compounds. These results demonstrated that ⁴⁸V(IV)O-Pheo may be useful as a new radiophamaceutical for tumor diagnosis, which can be conjugated with the photodynamic therapy using light and pheophorbide.

For understanding the physiological roles and the redox pathway of vanadium compounds, through which the metal ions are transfered to appropriate locations, the distribution of vanadyl (+4)species, estimated by ESR, and total vanadium, determined by neutron activation analysis, were examined in organs and subcellular fractions of the liver of rats treated with vanadyl (+4) sulfate or sodium vanadate (+5).Both vanadium compounds distributed in a similar manner in the following orders; kidney > serum > liver ≈ blood > pancreas > testis > lung ≈ spleen. The ratio of vanadyl ion to total vanadium in a whole homogenate was almost the same after the both treatments, but the ratios in subcellular fractions varied depending on the vanadium compound and the fraction. Approximately 30-70% of the vanadate was reduced to vanadyl form in the subcellular fractions of the liver.

Requirement of essential amino acid for growing rats was examined on the basis of hepatic cysteine dioxygenase (CDO) activity and urinary taurine. Young male rats were fed on semipurified diets of 0.45% sulfur amino acids (Met + Cys, 7:5) and different level of threonine, tryptophan and histidine for 18 days. Levels of threonine, tryptophan and histidine in each experimental diet were adjusted to six levels (0.125, 0.250, 0.300; 0.350, 0.400, and 0.500%), five levels (0.050, 0.075, 0.100, 0.125, and 0.150%) and four levels (0.15, 0.20, 0.25 and 0.30%), respectively. Minimum requirement of threonine was resulted in 0.48% in CDO activity and 0.39% in urinary taurine and that of tryptophan was resulted in 0.13% in CDO activity and 0.13% in urinary taurine. Essentials of histidine was recognized in this experiment.

Neonatal and infantile vitamin K deficiencies cause melena neonatorum and intracranial hemorrhagic disorders. There have been some suggestions as to how to prevent babies from having vitamin K deficiency. To prevent melena neonatorum, we have administered vitamin K₂ syrup(MK-4) to 15 mothers before delivery (group A), and measured MK-4 in maternal and umbilical cord plasma and breast milk. The mean MK-4 values in maternal and umbilical cord plasma and in breast milk of group A were significantly higher than those of 15 cases of age and race matched control (group B). Therefore, the method of giving vitamin K₂ syrup to mother before delivery is preferable than intramuscular injection to neonate, which involves a certain degree of danger. This preventive method is safe, and causes early and continuous transportation of MK-4 to neonate. In addition to that, it may be effective to decrease the perinatal bleeding of mother which is due to her vitamin K deficiency.

Titanium (Ti) is a common element widely spread in the earth’s crust, but it is not known whether Ti is an essential element or not. Pais et al. found out that titanium-ascorbate (Ti-AsA) promoted growth in some plants. We are now investigating the essentiality of Ti in animals. For this purpose, we prepared ⁴⁵TiCl₄ and ⁴⁵Ti-AsA, and investigated their biochemical behaviors.

Guinea pigs fed experimental diets (low AsA: 28mg AsA/100g diet, high AsA: 4000mg AsA/100g diet) for two weeks, were administered with ⁴⁵TiCl₄ and ⁴⁵Ti-AsA. The tissue uptake of ⁴⁵TiCl₄ was accompanied by a parallel rise of AsA level in the diet. On the other hand, the uptake of ⁴⁵Ti-AsA was not enhanced by AsA level in the diet, although tissue uptake was high even in case of low AsA level in diet.

Whole-body autoradiograms were performed with ⁴⁵TiCl₄ or ⁴⁵Ti-AsA in Wistar rat. ⁴⁵Ti-AsA was well distributed rather than ⁴⁵TiCl₄. These data indicate that AsA promotes the transport of Ti. Metabolites of ⁴⁵Ti-[¹⁴C]-AsA in the plasma of rats were analyzed by HPLC using gel filtration or ion-exchange technique. Ti-AsA mainly exists as Ti-AsA-transferrin complex in vitro.

Seasonal change in content of free amino acids (FAA), trimethylamine oxide (TMAO) and non protein nitrogen (NPN) was investigated in the shucked whole body and adductor muscle of the cultured oyster Crassostrea gigas. The whole body was abundant in FAA such as glutamic acid, glycine, alanine, proline and taurine. The adductor muscle contained glutamic acid, glycine, alanine, β-alanine, proline, arginine and taurine in relatively high contents. Levels of TMAO were negligible in both the whole body and adductor muscle. In the whole body, contents of proline and glycine were lowest in summer. In the adductor muscle, the aforementioned FAA except alanine and taurine also showed the lowest values in summer. NPN contents in both the whole body and adductor muscle were lowest in this season. The seasonal change in content of the FAA was discussed in relation to the paratability of oyster meats.

Ohta et al. have already reported that the low moleculer fraction (L.M.F.) of the oyster extract possessed inhibitory effects on platelet aggregation. Some fractions of L.M.F. indicating such strong effects included nucleic substances, i.e. 5’-AMP, Inosine and cyclicAMP. In this study, we investigated and focused on the type and amount of the nucleic related substances in O.E. and their corresponding biological effects. The O.E. was abundant in 5’-AMP, 5’-IMP, Inosine, 5’-GMP, Adenosine and Guanosine. The inhibiting effects on the platelet aggregation of 5’-AMP, Adenosine and Inosine were confirmed. From the results it was suggested that at least the structure of the purine base plus ribose was needed to exhibit such effect.

Arsenic compounds were extracted with chloroform/methanol/water from tissues of marine animals (four carnivores, five herbivores, five plankton feeders). The extracts were purified by cation and anion exchange chromatography. Arsenobetaine, dimethylarsinic acid, trimethylarsine oxide and arsenite, arsenate and methylarsonic acid as a group with the same retention time were identified by high-pressure liquid chromatography. Arsenobetaine found in all the animals was almost always the most abundant arsenic compound in the extracts. These results show that arsenobetaine is present in marine animals independently of their feeding habits and trophic levels.

Arsenobetaine-containing growth media (ZoBell 2216E; solution of inorganic salts) were mixed with coastal marine sediments as the source of micro-organisms. Arsenobetaine was converted in both media to trimethylarsine oxide and trimethylarsine oxide was converted to arsenite, arsenate or methylarsonic acid. The conversion rates in the inorganic medium were faster than in the ZoBell medium.

Fish soft roe contains protamine, histone (they are basic protein.) and nucleic acids. Protamine in fish soft roe has been well studied, while little is known about the nucleic acids in it. In this study, we studied about the nucleic acids in salmon soft roe.

Salmon soft roe was boiled and delipidated with EtOH to obtain sample A. Sample A was further extracted with 2M NaCl and protein fraction in sample A was removed to obtain sample B. The nucleic acids and amino acids were analyzed by HPLC. Sample A contained AMP 12.2%, TMP 10.0%, GMP 9.3% and CMP 6.4%. Sample A contained much arginine (16.1 %). About the PCA soluble substances, Sample A contained adenine 0.013%, hypoxanthine 0.08% and inosine 0.014%, while sample B contained adenine 3.4% and hypoxanthine and inosine were not detected.

Clinical trials were done to study the influence of ingestion of sample A and vitamin C on the number of leukocyte and platelet of cancer patients who received 5-FU (anticancer agent). In control group, the number of leukocyte and platelet was decreased and the administration was stopped. In contrast, that of the group that received the sample A and vitamin C were in more normal range than control group(especially the group that received the mixture of sample A and vitamin C.).

Sample A, B and other authentic nucleic acids were administered orally to the Wistar male rats for two weeks to examine the influence on the platelet aggregation.DNA (Wako) and RNA (Sigma) were used for authentic nucleic acids.

The administration of DNA suppressed the ADP-induced platelet aggregation slightly, while other samples did not.