Klaus Schwarz

Chromium (III) binding to serum proteins, specifically siderophilin

Abstract 1. 1. Tracer and 1 μg/100 g body weight levels of 51Cr(III), given by stomach tube as hexaaquo chloride to rats, were at the highest level in the blood 1 h following administration. They subsequently decreased logarithmicly to 20% of the peak value after 24 h. 2. 2. Over 99% of the 51Cr in blood was associated with the non-cellular component. 3. 3. When given in vivo about 90% of the “carrier-free” 51Cr in the serum was found to be attached to the β-globulin fraction upon paper electrophoresis. 4. 4. Serum labelled in vitro with tracer amounts of 51Cr contained about 70% of the isotope in the β-globulin fraction. 5. 5. Starch-gel electrophoresis and subsequent autoradiography of serum labelled with trace amounts of 51Cr and/or 55Fe demonstrated that the 51Cr was located with the siderophilin in a patern similar to that of 55Fe. When siderophilin was precipated from 51Cr-labelled human serum, 80% of the isotopes was present in the precipitate. 6. 6. After application of excessive amounts of Cr(III) or Fe(II), a relative increase of the percentage of bound chromium at the expense of the β-globulin fraction was seen in all other serum protein fractions. 7. 7. Chromium (CrCl3 · 6H2O), added in vitro to serum interfered with the subsequent color formation due to the addition of iron to siderophilin. This interference occurred only at near saturation levels.

Production of Dietary Necrotic Liver Degeneration Using American Torula Yeast

Summary American torula yeast, when used as the sole protein source in Vit. E free diets, induced dietary necrotic liver degeneration in rats in the same manner as reported for European yeasts. Other American yeasts did not produce the defect. With 30% torula yeast in the diet the incidence of liver degeneration in 15 consecutive experiments was 100%, the average survival time was 45.5 days. L-Cystine reduced the incidence of the defect considerably; however, even 1.0% did not give full protection when supplementation started at the 25th day. Five mg % vit. E prevented the defect completely. Necrosis of the liver developed very suddenly after an experimental period of 22 to S3 days and was accompanied by kidney lesions, forestomach ulcers, acute lung edema and hemorrhages in the lungs, in the lymphatic tissues and occasionally in the intestine. Acknowledgment is made to Mr. Louis E. Lowman and Mr. William Beane for technical assistance.

A hitherto unrecognized factor against dietary necrotic liver degeneration in American yeast (factor 3).

Summary (1) It is shown that yeast G (cultured, primary dried yeast) and yeast K (debittered, dried brewers yeast), which do not induce liver degeneration, exert a strong protective influence when added to diets causing the disease. It has been demonstrated by fractionation experiments that this effect is not due to vit. E or cystine, but due to a third unidentified factor, designated factor 3, which has been concentrated from yeast K. (2) The presence of factor 3 explains why dietary necrotic liver degeneration cannot be produced with American yeasts G and K. Factor 3 is water soluble, stable against acid hydrolysis, and is not identical with any one of the presently well-known vitamins.

Vitamin E, Trace Elements and Sulfhydryl Groups in Respiratory Decline: (An Approach to the Mode of Action of Tocopherol and Related Compounds)

Publisher Summary Respiratory decline, characteristic of vitamin

Casein and Factor 3 in Dietary Necrotic Liver Degeneration; Concentration of Factor 3 from Casein

:-deficient liver tissue during the prenecrotic phase of dietary necrotic liver degeneration, consists of the breakdown of respiration in vitro , after brief, initial periods of normal oxygen consumption. The phenomenon is observed with liver slices and also homogenates, but not with isolated mitochondria from the livers of animals during the latent phase of the disease. Respiratory decline is not related to the rate of peroxide formation in the homogenate. Combination experiments disclosed that microsomes exert a deleterious effect on the respiring E-deficient mitochondria. This effect is prevented by complexing agents such as KDTA. The initiation of respiratory decline is related to disturbances of trace element balance. The initiation of respiratory decline is related to disturbances of trace element balance. A loss of titrable sulfhydryl groups is related to the breakdown of respiratory activity. Reduced glutathione and diniercaptopropanol prevent respiratory failure. It is concluded that the immediate cause of respiratory decline is a block, by a trace element(s), of sensitive sulfhydryl sites (or another highly sensitive site) on an enzyme indispensable for respiration in mitochondria.

Relation of tocopherol to enzyme sulfhydryl sites

Summary 1. Samples of crude and “vit. Free,” alcohol-extracted casein, and also enzymatic casein digests, were found to contain considerable amounts of factor 3, which protects against dietary necrotic liver degeneration. This explains why the deficiency does not develop on customary vit. E free casein diets. 2. A method is described for the concentration of factor 3 from an enzymatic casein hydrolysate, affording a 30-fold purification in 3 steps, with an over-all recovery of about 38%. This concentrate is being used for the further purification of factor 3.

Ineffectiveness of Factor 3-Active Selenium Compounds in Muscular Dystrophy of Rabbits on Vitamin E-Free Diets

Tocopherol affects neither cytochrome oxidase nor antimycin A sensitivity of α-tocopherol-deficient rat liver homogenates. The decline of α-ketoglutarate oxidation by these homogenates can be prevented by glutathione and BAL. A concomitant decline of free sulfhydryl groups in the homogenate with time can be prevented by all the reagents which protect against oxidative decline. Tocopherol lowers the sensitivity to arsenite and cadmium ions of α-ketoglutarate oxidation in cell fractions. Similarly, tocopherol can largely prevent inhibition of glutamate and β-hydroxybutyrate oxidation by p-hydroxymercuribenzoate. Protecting agents are required at the beginning of the incubation period, but the presence of DPN with the homogenate extends the critical period for the addition of these agents. It is concluded that tocopherol acts in some way to maintain the proper functioning of enzyme sulfhydryl groups.

In vitro effect of tocopherol metabolites on respiratory decline in dietary necrotic liver degeneration

Summary Muscular dystrophy developed within 3 weeks in young rabbits fed a basal Vit. E-free diet which contained soybean meal as the protein source. Sodium selenite, and selenocystine, when added to the basal diet as sources of Factor 3-activity, did not influence the course of the disease. Control rabbits fed the basal diet but supplemented with α-tocopheryl acetate grew at normal rate of over 30 g/day and remained in good health. Factor 3 assays in rats, and also activation analysis for selenium, established that an adequate level of Factor 3 was present in the basal soybean meal diet. Under our conditions, muscular dystrophy is due to lack of tocopherol alone. Factor 3-active selenium compounds do not substitute for Vit. E.

Reversal of respiratory decline in necrotic liver degeneration by intraportal antioxidants.

The latent phase of necrotic liver degeneration in the rat, produced by dietary deficiency of vitamin E and Factor 3, is characterized by respiratory decline, i.e., a failure of respiration of liver slices in the Warburg. Tocopherol readily reverses this defect when injected intravenously but not when added to the Warburg medium. The in vitro effect of various tocopherol derivatives on respiratory decline was investigated. DL-α-tocopherol, d-α-tocopheryl polyethylene glycol-1000 succinate, DL-α-tocopherylhydroquinone, DL-α-tocopherylquinone, and DL-“α-tocopheroxide” (acetal of α-tocopherylquinone) did not influence the breakdown of respiration. Two tocopherol metabolites, isolated from the urines of rabbits and humans, 2-(3-hydroxy-3-methyl-5-carboxy)-pentyl-3,5,6-trimethylbenzoquinone and its γ-lactone, were found to prevent respiratory decline when added to the Warburg medium. A dose response curve was obtained. The 50% effective dose was at approx. 6.25 μg. The diacetate of the hydroquinone of the lactone was active at higher dose levels. The significance of the findings is discussed. In addition to the effect on respiratory decline, the γ-lactone at levels of 100 μg per flask produced a stimulation of the initial O2 consumption. The stimulatory effect was less pronounced, but present, with liver slices from normal controls.

INTRODUCTION: LIVER NECROSIS VERSUS FATTY LIVER AND CIRRHOSIS

Summary The effects of intraportal injections of antioxidants on respiratory decline in dietary necrotic liver degeneration were investigated by comparing respiration of liver slices from rats before, and 30 minutes after injection. Several antioxidants (DPPD. San-toquin, Santoflex B, and di-tert-amlhydroquinone) were like α-tocopherol quite effective in the reversal of respiratory decline at doses of 1 mg or less, while others (NDGA. n-Propylgallate, BHA, Propylparasept, hydroquinone) were without any effect. Screening of 13 different compounds led with but few exceptions to the same scale of relative potencies as that obtained previously for protection against necrotic liver degeneration by feeding of the antioxidants in the necrogenic diet. Intraportal injection of 14.5 μg of DPPD was required to produce 50% reversal. On a molar basis, DPPD was twice as active as D, L-α-tocopherol. It is concluded that the protective effect against necrotic liver degeneration is not due to the prevention of autoxidation in the diet or in the gut; rather, it takes place within the organism itself.