Stephan Ludewig

Lipid Distribution in Rat Liver After Partial Hepatectomy

Summary During the first 24 hours after partial hepatectomy, the liver remnant becomes fatty due particularly to the deposition of large amounts of neutral fat and to increases in the phospholipid and cholesterol fractions. On the second and third days there is an appreciably sharp decrease in the concentration of all the lipid constituents. After 7 days the lipid values are all slightly above the respective control values excepting the combined cholesterol which is decreased. The iodine numbers of the total fatty acids remain constant but those of the phospholipids increase progressively during the experimental period. Liver injury produced by partial hepatectomy results in a marked disturbance in lipid metabolism. Regeneration of this tissue is accompanied by a return to normal values.

Hemosiderin V: The occurrence of heme and lipids in hemosiderin☆☆☆

Abstract Hemosiderin was prepared from hemosiderotic human tissue by methods formerly developed for horse spleen. The chemical characteristics of the hemosiderin prepared from either human liver or human spleen resemble those of horse spleen hemosiderin. Only N-acetylneuraminic is present as the sialic acid component of the carbohydrate complex of human hemosiderin. In hemosiderin of both species, the porphyrin present has been identified as protoheme IX; it is apparently formed from the breakdown of discarded red blood cells in the phagocytes of liver and spleen. The data available do not warrant the conclusion that protoporphyrin IX is present in hemosiderin. Chloroform-methanol extracts of iron-free aposiderin of both species yield a variety of lipids, e.g., phospholipids, cerebrosides, ganglioside, and cholesterol. The qualitative distribution of these lipids resembles that of the red cell and it is suggested that these lipids are derived from the stroma of broken-down red cells. From the data presented the conclusion is drawn that the chemical characteristics of human and horse hemosiderin are similar and that the preparations are not artifacts but represent an entity, the pigment hemosiderin.

Hemosiderin; isolation from horse spleen and characterization.

Summary 1. A method is outlined for isolating hemosiderin from horse spleen by sedimentation from salt solutions of different specific gravities. 2. The iron, nitrogen, phosphorus and ash concentration varied considerably in hemosiderin samples obtained from different spleens. Fractionation of these preparations by sedimentation in organic liquids showed that fractions could be obtained which varied in their iron concentrations from about 25 to 41% iron. 3. Hemosiderin has been found to contain hexoseamine, galactose, mannose and fucose.

Hemosiderin (III): Determination of sialic acid and the components of a carbohydrate complex☆

Abstract It has been shown that hemosiderin contains two sialic acids: N-acetylneuraminic acid and glycolylneuraminic acid. These acids are found in both of the iron-free derivatives of hemosiderin: the insoluble aposiderin and the soluble component. Both of these fractions contain the same ratio of sialic acid to hexoses, fucose, and hexosamine, respectively. This suggests that the character of the glycoprotein-like compounds in these fractions is similar. Wohlers finding of deoxyribose and guanine in aposiderin could not be corroborated. The presence of iron interferes in the determination of sialic acid in hemosiderin.

Hemosiderin (IV): Effect of iron on the determination of bound sialic acid and on deoxyribose

Abstract The presence of iron in hemosiderin interferes with the determination of the bound sialic acid, and low values are obtained. The iron released during acid hydrolysis breaks down the sialic acid molecule. This effect of iron is studied by adding iron to sialic acid, aposiderin, and transferrin. The addition of iron does not alter the character of the spectrum of the thiobarbituric acid assay of sialic acid. Deoxyribose, when heated in 0.1 N H2SO4 at 80 ° for 45 minutes, will be partially decomposed. In the presence of iron this breakdown is increased.

Hemosiderin: iron extraction studies.

Summary 1. It has been demonstrated that iron is extracted from horse spleen hemosiderin at different rates by disodium ethylenediamine tetraacetate. During the first 24 hours of extraction, between 21 and 70% of total hemosiderin iron was removed by chelating agent from 8 hemosiderin preparations which contained between 33.5 and 19% iron, respectively. The amount of iron removed is inversely proportional to total hemosiderin iron concentration. Subsequently, iron is dissolved at a slow rate until practically all is removed during 25 days extraction. 2. Analytical data for amount of ferritin present in hemosiderin are presented.

Alpha naphthylthiourea (ANTU) in dogs; electrophoretic and cholesterol studies on blood plasma and pleural effusion.

Summary and Conclusion Oral and intravenous administration of lethal doses of alpha naphthylthiourea (ANTU) to 4 dogs caused death by affecting the permeability of pulmonary and pleural capillaries, which resulted in marked pulmonary edema and pleural effusion. Electrophoretic and nitrogen determinations of the sera showed consistent decreases in the concentration of albumin several hours before death. The proteins of the pleural effusion showed a higher albumin : globulin ratio than those of the serum. The total plasma cholesterol concentration decreased shortly before death and was approximately the same in the effusion. Dogs fed increasingly greater amounts of ANTU during frequent intervals develop a tolerance for large doses of the drug. An increase in the serum α globulin concentration appeared to be a characteristic finding in the development of the tolerance. The plasma cholesterol concentration increased markedly during drug administration and diminished when it was discontinued.

Distribution of 2,2 (p-Chlorophenyl) 1,1,1 Trichlorethane (DDT) in Tissues of Rats after Its Ingestion.

Summary The DDT contents of the liver, kidney, brain antl adrcnals of rats fed diets containing 0.1% and 0.2% UDT were determined al various intervals. The amounts of this agent stored in the respectivc tissues reaches a maximum within a few days and remains at a constant level in animals fed 0.1% DDT. The greatest concentration was noted in the adrenals. The concentrations of DDT in the brain, liver antl kidney of rats fed 0.2% DDT increaie slightly and progressively with time. The concentration of this material is markedly increased in the adrenal at the time when the animals are severely intoxicated.