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At least 19 recordsLinked to original sources
PubMed1975

Effect of the dietary manganese level on tissue manganese, iron, copper and zinc concentrations in female rats and their fetuses.

In order to study the effect of dietary manganese on the content of manganese, iron, copper and zinc in maternal and fetal tissues, six diets with different levels of manganese (4, 24, 54, 154, 504 and 1004 mg Mn/kg dry diet) were fed to Sprague-Dawley female rats from the time of weaning. The animals were mated and the offspring collected by cesarean section at day 21 of pregnancy. Non-pregnant female rats served as respective reference groups. Concentrations of copper as well as manganese were higher in the livers of pregnant rats with the highest manganese intake, whereas in non-pregnant animals the dietary manganese level had no appreciable effect on manganese or copper concentrations in the liver. On the other hand, the iron content of the livers of both pregnant and non-pregnant female rats fell as the manganese level of the diet increased. The hemoglobin values of dams on the highest levels of dietary manganese were also slightly reduced. The manganese content was highest in the offspring of dams given the largest amounts of manganese. The manganese level in the maternal diet had the opposite effect on the fetal iron concentration, and the zinc content of fetuses of dams on the highest dietary manganese level was slightly elevated. No gross malformations or bone structure anomalies could be observed in the fetuses, and the manganese intake of the dams was not found to have influenced essentially the fetal weights and the dry matter and ash contents.

Animals↗
PubMed1976

Effects of zinc, copper, and manganese supplementation of high-concentrate ration on gastrointestinal absorption of copper and manganese in Holstein calves.

Sixteen Holstein bull calves were fed a high-concentrate ratio supplemented with zinc, copper, and manganese, alone or in combination, for 10 wk. After 6 days of preliminary feeding of chromic oxide, fecal grab-samples were collected for 6 days. Calves were slaughtered, and samples of the contents of the reticulo-rumen, omasum, abomasum, small intestine, cecum, and large intestine were analyzed for chromic oxide, copper, and manganese. Absorption along the gastrointestinal tract, measured by comparison of one segment with the previous segment, indicated net secretion of copper in the abomasum but net absorption from the rest of the tract. The exception was that net secretion into the reticulo-rumen was associated with low dietary copper. Net secretion of manganese was mainly in the small intestine and cecum in all treatments. A higher proportion of copper apparently was absorbed when this mineral was supplemented in the ration. However, absorption of manganese was decreased slightly when manganese was supplemented in the ration. Reabsorption of manganese in the large intestine was probably greater than that of copper.

Absorption↗
PubMed1977

Effect of manganese on neonatal rat: manganese concentration and enzymatic alterations in brain.

Suckling rats were exposed for 15 and 30 days to manganese through the milk of nursing dams receiving 15 mg MnCl2--4H2O/kg/day orally and after which the neurological manifestations of metal poisoning were studied. No significant differences in the growth rate, developmental landmarks and walking movements were observed between the control and manganese-exposed pups. The metal concentration was significantly increased in the brain of manganese-fed pups at 15 days and exhibited a further three-fold increase over the control, at 30 days. The accumulation of the metal in the brain of manganese-exposed nursing dams was comparatively much less. A significant decrease in succinic dehydrogenase, adenosine triphosphatase, adenosine triphosphatase, adenosine deaminase, acetylcholine esterase and an increase in monoamine oxidase activity was observed in the brain of experimental pups and dams. The results suggest that the developing brain may also be susceptible to manganese.

Acetylcholinesterase↗
PubMed1976

Manganese-dependent NADPH oxidation by granulocyte particles. The role of superoxide and the nonphysiological nature of the manganese requirement.

Recent work has indicated that superoxide is involved in the manganese-stimulated oxidation of NADPH by crude granule preparations of guinea pig neutrophils. The characteristics of a model manganese-requiring NADPH-oxidizing system that employs a defined O2-generator have now been compared to the original neutrophil-granule system. With respect to pH dependence, cyanide sensitivity, and reduced pyridine nucleotide specificity, the properties of the two systems are very similar. Additional information has been obtained concerning cation specificity and the kinetics of the metal-catalyzed NADPH oxidation. From the similarities between the properties of the model and neutrophil particle systems, we postulate that the manganese-dependent NADPH oxidation observed in the presence of neutrophil granules represents in large part of nonenzymatic free radical chain involving the oxidation of NADPH to NADP, with O2- as both the chain initiator and one of the propagating species. In this reaction, the neutrophil particles serve only as a source of O2-. Further, the same changes in kinetics (decrease in apparent Km for NADPH) observed previously when granules from phagocytizing rather than resting cells were employed could be mimicked by varying the rate of O2-generation by the model system. We conclude from these results that it is unnecessary to invoke a manganese-requiring enzyme as a component of the phagocytically stimulated respiratory system of the neutrophil.

Animals↗
PubMed1975

Manganese mutagenesis in yeast. A practical application of manganese for the induction of mitochondrial antibiotic-resistant mutations.

When yeast cells were incubated for 4 to 8 h in yeast extract-peptone-glucose medium, pH 6, containing 8 mM-manganese, and then plated on selective media, there was a strong induction of antibiotic-resistant mutations. Indirect evidence suggests that practically all resistant mutants selected were of independent origin. The analysis of manganese-induced resistant mutants showed that most were extranuclear, while those tested showed recombination with known mitochondrial markers. Our results suggest that manganese can be considered as a mutagen which specifically induces mitochondrial mutations in Saccharomyces cerevisiae.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Manganese concentration by microorganisms inhabiting the soils of a manganese biogeochemical province in Georgia].

The concentrating of manganese by microorganisms was studied with bacteria, actinomycetes and fungi inhabiting soils of the manganese biogeochemical province of the Georgian Republic with different content of this element (from 1045 to 296 000 mg/kg of dry weight). The amount (from 4.0 X 10(-3) to 10 per cent per dry substance) and character of manganese accumulation by microorganisms were found to depend on the content of this element in the growth medium, the taxonomic position of microorganisms, and their adaptation to geochemical conditions.

Bacillus megaterium↗
PubMed1975

Removal of manganese by chelating agents from brain and liver of manganese treated rats: as in vitro and an in vivo study.

Some chelating agents were examined for their ability to remove manganese from brain and liver (in vivo) and their sub-cellular fractions (in vitro), of rats pretreated with manganese sulphate. Nitrilotriacetic acid (NTA), 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA) and diethylenetriaminepentaacetic acid (DTPA) were extremely effective in vivo while CDTA and p-aminosalicylic acid (PAS) were efficient in vitro.

Animals↗
PubMed1978

Manganese status of pasturing ewes, of pregnant ewes and doe rabbits on low manganese diets and of dairy cows with cystic ovaries.

Four experiments were conducted to obtain information on the manganese (Mn) status of ewes, doe rabbits and dairy cows with cystic ovaries. Manganese was not concentrated specifically in any one tissue or organ but the use of 54Mn has indicated that the isotope was retained by the liver for a longer time. Significantly lower (P less than 0.01) levels of Mn were observed in the liver, kidney and blood of pregnant ewes fed a synthetic diet containing low levels (5 ppm) of Mn than those that were supplemented with 60 ppm Mn. It would appear that the determination of blood Mn concentration would provide a valuable diagnostic tool for the assessment of the Mn status of the pregnant ewe and could be more reliable than data based on tissue (liver, kidney, ovary) levels of Mn. The cortical stroma of dairy cows with cystic ovaries had lower Mn contents than those cows that were without cystic ovaries. The data on blood suggests that cystic ovaries cannot be diagnosed by blood Mn levels if Mn was indeed a contributing factor of the development of this condition. The doe rabbit responded to supplemental dietary Mn in a manner analogous to the ewes.

Adrenal Glands↗
PubMed1979

Evaluation of the chronic inhalation toxicity of a manganese oxide aerosol. III. Pulmonary function, electromyograms, limb tremor, and tissue manganese data.

Monkeys and rats were exposed to 11.6, 112.5, and 1152 micrograms Mn/m3 as an Mn3O4 aerosol twenty-four hours per day for nine months. Various evaluations of pulmonary function, electromyographic activity, limb tremor, and tissue manganese levels were conducted. No exposure related effects on pulmonary function, limb tremor, or electromyographic activity were observed. After nine months of exposure Mn levels were elevated in a near dose related manner in kidney, lung, spleen, and blood. However, by six months postexposure there were no differences as compared to the control group in tissue Mn levels which could be attributed to the exposure conditions.

Aerosols↗
PubMed1977

Effect of human chorionic gonadotropin on the transport of manganese and zinc and tissue uptake of radioactivity following subcutaneous administration of tritiated estrone in manganese deficient and nondeficient rabbits.

Twenty-four eight month old virgin New Zealand doe rabbits were used in an experiment designed to study the effect of human chorionic gonadotropin on the transport of 54Mn and 65Zn in their tissues. Although human chorionic gonadotropin treatment did not result in any change in 65Zn transport, that of 54Mn was affected. In another experiment, the tissue uptake of tritiated estrone was studied in manganese deficient and nondeficient rabbits. There were no differences in radioactivity uptake between the two diets but the pattern of tissue uptake was different from other reports.

Animals↗
PubMed1976

Manganese (II) and substrate interaction with unadenylylated glutamine synthetase (Escherichia coli w). II. Electron paramagnetic resonance and nuclear magnetic resonance studies of enzyme-bound manganese(II) with substrates and a potential transition-state analogue, methionine sulfoximine.

The enhancement of the longitudinal proton relaxation rate of solvent water protons which occurs when Mn(II) is bound to the "tight" metal ion site of unadenylylated glutamine synthetase (GS) was used to determine the binding constant of L-methionine (SR)-sulfoximine to GS-Mn(II) complexes. The binary enhancement for GS-Mn(II) is 22 at 24 MHz, 25 degrees C. The enhancement is lowered in the presence of the sulfoximine and the computed dissociation constant is 30 muM with epsilont, the enhancement for the ternary complex, equal to 3.0. Titration curves for the sulfoximine were also obtained in the presence of Mg-ADP, Mg-ADP plus Pi, and Mg-ATP. The dissociation constants were 9, 5, and 0.8 muM, respectively. The progressive tightening of the dissociation constants is symptomatic of conformational changes at the active site as the total subsite occupied by ATP is filled. The number of rapidly exchanging water molecules drops from 2 to approximately 0.1 when saturating concentrations of L-methionine (SR)-sulfoximine and nucleotide are present. The kinetically determined KI value of approximately 4 muM for the sulfoximine is about three orders of magnitude tighter than thee Km' value of approximately 3 mM for L-glutamate. The previously mentioned dissociation constants obtained by enhancement titrations are also orders of magnitude tighter than Km'. These data suggest that L-methionine (SR)-sulfoximine is a "transition-state" analogue for the glutamine synthetase reaction. ...

Adenine Nucleotides↗
PubMed1979

[The supply of wild ruminants with major and trace elements. 2. The manganese content of winter grazing and the manganese status of red deer, fallow deer, roes and mouflons].

The winter grazing of wild ruminants on mantles of slate waste in the Harz mountains and in Gera county were richest in Mn whereas those on mantles of granite waste in the Erzgebirge were poorest. The flora of the shell-limestone, keuper and loess areas contains much less Mn than that of those acid habitats. The Mn-requirement of the wild ruminants grazing in the forests is met however, since bilberry plants (2,080 mg/kg), spruce twigs (984 mg/kg), spruce bark (827 mg/kg), oak twigs (791 mg/kg) and heather (754 mg/kg dry matter) in addition to many other plant species store extremely high amounts of Mn. Solely sallow twigs were poor in Mn (28 mg/kg). Based on 601 samples examined, the Mn supply of wild ruminants is extensively described. The rumen content reflected the plentiful Mn-supply of the wild ruminants living in forests (greater than 400 mg/kg) and the far worse one of field roes, particularly in Mn-deficiency areas for domesticated ruminants (mantle of shell-limestone waste 37 mg Mn/kg dry matter of rumen content). The indicator organs of the Mn-status (liver, covering hair, kidneys) verify the statements made concerning red deer, fallow deer and mouflons, of which a total of 170 head from 14 biotopes were examined. An Mn-deficit of field roes in Mn-deficiency habitats in winter cannot completely be excluded. Mouflons have not yet been able to adapt themselves to the excessive Mn-supply of the acid forest habitats in Central Europe. They stored significantly higher amounts of Mn in liver, covering hair, kidneys, cerebrum and ribs than the other wild ruminants and sheep and cattle. The normal Mn-content of the liver and the cerebrum of red deer, fallow deer and roes corresponds to that of sheep and cattle. Roes and fallow deer have winter covering hair poor in Mn (less than 4.0 mg/kg) in comparison to sheep and cattle.

Animal Nutritional Physiological Phenomena↗