Distribution of Added Lead and Cadmium in Human and Bovine Milk

1995 ◽  
Vol 58 (3) ◽  
pp. 305-309 ◽  
Author(s):  
LUIS MATA ◽  
M. DOLORES PEREZ ◽  
PILAR PUYOL ◽  
MIGUEL CALVO
Keyword(s):  
Molecular Weight ◽  
Human Milk ◽  
Bovine Milk ◽  
Gel Filtration ◽  
Weight Fraction ◽  
Acid Precipitation ◽  
Low Molecular Weight ◽  
Lead And Cadmium ◽  
Skimmed Milk ◽  
Enzymatic Coagulation

Distribution of added lead and cadmium to bovine and human milk and whey has been studied. In bovine milk, about 97 and 89% of lead and cadmium, respectively, were recovered in the casein fraction obtained by enzymatic coagulation. However, only 6% of lead and 41% of cadmium were found in the same fraction separated by acid precipitation, indicating that the distribution of both metals is very different depending on the method used for milk fractionation. Moreover, gel filtration of bovine and human skimmed milk and whey after addition of lead and cadmium was carried out. Most of the lead was associated to the casein fraction after gel filtration of skimmed milk, whereas in the chromatography of whey, lead was eluted with the low molecular weight fraction in both species. However, a different pattern in the distribution of cadmium has been observed in the two species studied. In contrast to the binding of cadmium to the low molecular weight fraction in human skimmed milk and whey, it was mainly associated to a component of a molecular weight around 70,000 in bovine skimmed milk. This component was not present in bovine whey indicating that it is separated with casein during fractionation.

In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

1981 ◽  
Vol 46 (03) ◽  
pp. 612-616 ◽  
Author(s):  
U Schmitz-Huebner ◽  
L Balleisen ◽  
F Asbeck ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Day Treatment ◽  
Gel Filtration ◽  
Weight Fraction ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Platelet Factor ◽  
Heparin Fractions

SummaryHigh and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

Absorption of trace metals in the zinc-deficient rat

1975 ◽  
Vol 228 (4) ◽  
pp. 1020-1023 ◽  
Author(s):  
CJ Hahn ◽  
GW Evans
Keyword(s):  
Molecular Weight ◽  
Trace Elements ◽  
Gel Filtration ◽  
Weight Fraction ◽  
Intestinal Content ◽  
Whole Body ◽  
Low Molecular Weight ◽  
Zinc Absorption ◽  
Body Absorption ◽  
Insight Into

The effects of zinc deficiency on the whole-body absorption and intestinal content of Zn, Cd, Cu, Co, Fe, Mn, and Cr were determined in the rat 1 h after oral administration of the isotopes. Both the absorption and intestinal content of Zn and Cr were increased in zinc-deficient rats, and the intestinal content of Feand Co was also increased in the zinc-deficient animals. Zinc administered orally with Cr decreased both absorption and intestinal content of the isotope in zinc-deficient rats. Chromium administered orally with Zn decreased intestinal content and absorption of Zn in zinc-deficient rats. Fractionation of mucosal supernatants by gel filtration showed that both zinc and chromium eluted in the same low molecular weight fraction. The elution patterns of zinc and cadmium from that of zinc-supplemented animals. These experiments provide some insight into the specificity of the zinc absorption pathway and present some explanations for the interaction or lack of interaction among trace elements.

Changes in the Distribution of Cadmium and Lead in Human and Bovine Milk Induced by Heating or Freezing

1996 ◽  
Vol 59 (1) ◽  
pp. 46-50 ◽  
Author(s):  
LUIS MATA ◽  
LOURDES SANCHEZ ◽  
PILAR PUYOL ◽  
MIGUEL CALVO
Keyword(s):  
Molecular Weight ◽  
Whey Proteins ◽  
Bovine Milk ◽  
Marked Change ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
Casein Micelles ◽  
Fat Fraction ◽  
Cadmium And Lead ◽  
Formation Of Complexes

The percentage of cadmium or lead present in the fat fraction of bovine milk is not affected by heating or freezing. In human skimmed milk, cadmium is mainly associated with a fraction with molecular weight lower than 10,000. Storage at −20°C for 10 days does not have any effect on the distribution of cadmium when milk is incubated with this metal before freezing. This treatment causes only a small increase in the amount of cadmium associated with the low molecular weight fraction when the metal is added after freezing. In bovine milk, 64% of cadmium is associated with a fraction with molecular weight above 70,000. Freezing causes a 37% decrease of the cadmium present in this fraction when the metal is added after thawing. When bovine milk was incubated with cadmium before freezing there was not a marked change in its distribution as when added after thawing. Heating at 63°C for 30 min caused a slight decrease in the amount of cadmium present in the casein fraction. The distribution change of cadmium after freezing or heating is probably due to the formation of complexes between the whey proteins and the metal, or to the disaggregation of the cadmium bound to casein micelles. Lead is mainly associated with caseins in bovine and human milk. No significant changes were caused by freezing or heating in the distribution of lead in human and bovine milk.

scholarly journals The Heterogeneity of the High Molecular Weight B12 Binder in Serum

Blood ◽  
1969 ◽  
Vol 33 (6) ◽  
pp. 899-908 ◽  
Author(s):  
CHRISTINE LAWRENCE
Keyword(s):  
Molecular Weight ◽  
Vitamin B12 ◽  
High Molecular Weight ◽  
Serum Proteins ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
Transcobalamin I ◽  
Transcobalamin Ii

Abstract The binding of vitamin B12 by serum proteins was studied by separating Co57B12-enriched serum by Sephadex gel filtration, column chromatography with DEAE-cellulose, and paper electrophoresis. Each method of separation yielded two discrete B12-binding fractions. However, the analysis of each serum by all three separation technics indicated that one of the fractions was, in each case, bipartite. The "high" molecular weight B12-binding fraction defined by Sephadex gel filtration consisted of transcobalamin I and just part of the transcobalamin II fraction. The remaining portion of transcobalamin II was eluted from Sephadex gel in a "low" molecular weight fraction. Thus, transcobalamin II, equivalent to the β-globulin B12-binder, consisted of both "high" and "low" molecular weight components. This suggests that there are at least three serum proteins that can bind vitamin B12: two β-globulins, together comprising the transcobalamin II fraction and differing in molecular weight; and transcobalamin I.

Tumor Uptake of High and Low Molecular Weight Fractions from 67Ga-Citrate Labelled Blood Plasma

1984 ◽  
Vol 23 (02) ◽  
pp. 59-61 ◽  
Author(s):  
M. C. Crone ◽  
P. Thouvenot ◽  
F. Brunotte ◽  
C. Marchai ◽  
J. Robert ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Blood Plasma ◽  
High Molecular Weight ◽  
Gel Filtration ◽  
Weight Fraction ◽  
Blood Protein ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
67Ga Citrate

SummaryBlood plasma from tumor-bearing rats was incubated with 67Ga-citrate, and two fractions of high molecular weight (proteins) and low molecular weight were isolated by dialysis and by gel-filtration chromatography. Both fractions showed a different in vivo uptake by DS-sarcoma-bearing animals, the high molecular weight fraction being accumulated to a lesser extent. Compared to 67Ga-citrate the low molecular weight fraction showed a different uptake which for most tissues was significatively higher. This behavior suggests the presence of 67Ga in chemical forms other than citrate in the low molecular weight fraction. The lower uptake of the blood protein fraction is discussed.

Generation of hydrogen peroxide by a low molecular weight compound in whey of Holstein dairy cows

2008 ◽  
Vol 75 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Senkiti Sakai ◽  
Takahiro Satow ◽  
Kazuhiko Imakawa ◽  
Kentaro Nagaoka
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Detection System ◽  
Bovine Milk ◽  
Gel Filtration ◽  
Low Molecular Weight ◽  
Dependent Manner ◽  
Amount Of Substance ◽  
Detection Systems ◽  
New Type

Using an ultrafiltration membrane (molecular cut-off, 3000), low molecular weight compounds in bovine milk were collected (YM-3 filtrate). A hydrogen peroxide (H2O2)-like substance was generated in the YM-3 filtrate. This substance was undetected at 0 h, but increased in a time-dependent manner, peaking after 2 h of incubation at 38°C. After incubating the YM-3 filtrate with catalase and lactoperoxidase, the signal showing the presence of this substance disappeared. The substance was quantified using one chemiluminescence and three colorimetric H2O2detection systems. In all systems, their estimates were within the same range. The amount of substance, as estimated by the chemiluminescence H2O2detection system, was correlated with that estimated by the other three colorimetric systems (r=0·98, 0·95 and 0·87). The substance was eluted at the same position as H2O2by gel filtration on Superdex 30. Thus, the substance had the same characteristics as H2O2. An H2O2-generating substance in either the YM-3 filtrate or whey had a molecular mass of about 600. In this study, we clarify that bovine milk is capable of generating H2O2by utilizing a low molecular weight compound. Thus, we present a new type of H2O2-supplying system in bovine milk.

scholarly journals Studies in sheep on the absorption of magnesium from a low molecular weight fraction of the reticulo-rumen contents

1988 ◽  
Vol 59 (1) ◽  
pp. 93-108 ◽  
Author(s):  
N. D. Grace ◽  
I. W. Caple ◽  
A. D. Care
Keyword(s):  
Molecular Weight ◽  
Absorption Rate ◽  
Rumen Fluid ◽  
Gel Filtration ◽  
Weight Fraction ◽  
Supernatant Fraction ◽  
Low Molecular Weight ◽  
Percentage Decrease ◽  
K Concentration ◽  
Absorptive Flux

1. Six sheep, three animals per diet, were prepared with rumen fistulas and fed on frozen grass or grass–maize pellets to give magnesium intakes of 1·79 and 2·23 g/d respectively. The mean apparent availabilities of Mg in sheep fed on frozen grass and grass–maize pellets were 0·31 and 0·36 respectively.2. The rumen contents were fractionated by straining the digesta through linen cloth and then differentially centrifuged to give 20 000gand 100 000gsupernatant fractions.3. In all sheep, regardless of diet, at 4 and 16 h after a meal, 50 and 60% respectively of the total Mg in the rumen contents was found in strained rumen fluid while 30 and 38% respectively of the total Mg was found in the 100 000gsupernatant fraction.4. The net absorption of Mg from the temporarily isolated and washed reticulo-rumen was studied using either 100 000 g supernatant fractions of rumen contents from sheep fed on one or other of the two diets, or inorganic buffers containing the same concentration of Mg and other macroelements.5. The Mg was readily absorbed from the 100 000gsupernatant fraction placed in the rumen with the rate of absorption being 7·3 μmol/1 per min (505 mg/d) from the supernatant fraction obtained from sheep fed on frozen grass and 11.3 μmo/1 per min (781 mg/d) from the supernatant fraction from sheep fed on grass–maize pellets. In the same sheep, the previously described rates of Mg absorption from the 100 000gsupernatant fraction were similar to those obtained from the comparable inorganic buffers.6. The effects of varying concentrations of potassium and sodium on the net absorption rate of Mg (as24Mg) and on the one-way efflux of Mg (as28Mg) from supernatant fractions or rumen fluid and inorganic buffers were investigated using the temporarily-isolated and washed rumen in three sheep. Although the net absorption rate of24Mg from supernatant fractions or buffers containing similar K concentrations varied significantly between sheep, a similar percentage decrease in the absorption rates of both24Mg and28Mg was found for each sheep as the K concentration was increased.7. One pair of sheep was fed on the frozen grass and the other pair was fed on the grass–maize pellets. Their daily intakes of K were then increased to 50 g/d for 14 d by intrarumen infusion of potassium chloride. In three of the four sheep the plasma Mg concentration fell within 12 h of the start of the KCl administration. In all sheep urinary excretion of Mg decreased and its faecal output increased. The increased intake of K had no effect on the distribution of Mg in the rumen contents.8. Gel-filtration chromatography of the 100 000gsupernatant fractions, regardless of the diet, showed that over 90% of the Mg in the 100 000gsupernatant fractions was associated with a low-molecular-weight fraction of about 200 Da which corresponded to the elution volume of magnesium chloride in 0·1 M-sodium chloride.9. It is concluded that any binding of Mg ions to small organic molecules in the 100 000gsupernatant fraction of rumen contents played no significant role in the restriction of Mg absorption from the reticula-rumen. The depressent effect of increased K concentration in rumen contents on the net absorption of Mg is via a reduction in the absorptive flux rather than by increased secretion of Mg into the rumen fluid.

scholarly journals Candidate markers for the detection of hepatocellular carcinoma in low-molecular weight fraction of serum

2007 ◽  
Vol 28 (10) ◽  
pp. 2149-2153 ◽  
Author(s):  
Radoslav Goldman ◽  
Habtom W. Ressom ◽  
Mohamed Abdel-Hamid ◽  
Lenka Goldman ◽  
Antai Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Weight ◽  
Weight Fraction ◽  
Low Molecular Weight

Basal Activity of the Natriuretic Factor Extracted from the Rat Kidney as a Function of the Diet and its Role in the Regulation of the Acute Sodium Balance

1980 ◽  
Vol 58 (5) ◽  
pp. 385-391 ◽  
Author(s):  
F. Louis ◽  
H. Favre
Keyword(s):  
Sodium Intake ◽  
Rat Kidney ◽  
Extracellular Volume ◽  
Gel Filtration ◽  
Kidney Tissue ◽  
Weight Fraction ◽  
Sodium Content ◽  
Sodium Balance ◽  
Low Molecular Weight ◽  
Extracellular Volume Expansion

1. The effect of the sodium content of the diet on the natriuretic activity of an extract from the kidneys was studied in non-expanded and volume-expanded rats. 2. The kidney tissue was homogenized and the supernatant fractionated by gel filtration on Sephadex G-25. A single low-molecular-weight fraction eluted after the salt possessed the natriuretic activity and was tested on a rat bioassay. 3. The natriuretic activity of the fraction obtained from the kidneys of non-expanded rats was related to the sodium intake. 4. After an acute extracellular volume expansion, the natriuretic activity obtained from the fraction extracted from the kidneys was much greater than before expansion and was related to the dietary intake of sodium.

HEMODIALYSIS OF THE RAT

1966 ◽  
Vol 44 (5) ◽  
pp. 849-859 ◽  
Author(s):  
Sumner M. Robinson ◽  
David A. Hurwitz ◽  
Robert Louis-Ferdinand ◽  
William F. Blatt
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Low Molecular Weight

A technique is described for hemodialysis of either anesthetized or non-restrained rats. In the apparatus the dialysis plates of an autoanalyzer system are used with only minor modification. The efficiency of this method has been evaluated with regard to the clearance of saccharides, both in vitro and in vivo, as well as the extraction of nitrogenous low molecular weight moieties from circulating blood. Approximately 50% of the dialyzable material was obtained in a 1-hour dialysis. Further fractionation of the dialyzate was accomplished by gel filtration (Sephadex G-25).

Sign in / Sign up

Export Citation Format

Share Document