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A SCANU

Publications and source records attributed to A SCANU.

At least 19 recordsLinked to original sources
PubMed1961

Triton hyperlipemia in dogs. II. Atheroscieross, diffuse lipidosis, and deletion of fat stores produced by prolonged administration of the non-tonic surface-active agent.

Fourteen dogs, fed a regular diet and given 250 mg/kg of triton (a non-ionic surface-active agent) intravenously every 4th day, exhibited a progressively severe hyperlipemia. Serum triglycerides were the first to increase. Cholesterol, mostly in the free form, and phospholipids showed elevation only at a later stage and increased at almost identical rates. The plasma-free fatty acid concentration was from 2 to 3 times above normal. With establishment of sustained hyperlipemia, there was reduction, followed by total disappearance, of the high density D 1.063 to 1.21 lipoprotein. Most of the cholesterol and phospholipids (70 to 75 per cent of the total) were found in the D 1.006 to 1.063 lipoprotein class, the remainder in the D < 1.006 class. Triglycerides were almost evenly distributed between these two classes. The concentration of the serum lipoprotein proteins was within normal limits. All of the animals died within from 4 to 5 months after receiving the first injection of triton. Autopsy findings consistently showed: (a) numerous lipidladen macrophages in the liver, spleen, and lymph nodes; (b) significant depletion of all fat stores; (c) presence of lipids, either free or engulfed in macrophages (foam cells), in the subintima of the coronary arteries, aorta, and pulmonary arteries, indicating an early stage of atherosclerosis. Concurrent daily administration of heparin (5 mg per kilogram of body weight) did not substantially change the course of the disease. Withdrawal of triton from animals that had been receiving the detergent for from 3 to 4 months, elicited a slow return to normal of the lipid pattern. In two dogs killed when normolipemia was reestablished, all tissues were normal with the minor exception of a few hepatic macrophages still laden with sudanophilic material. It is postulated that the primary action of the injected triton was on the lipid moieties of plasma lipoproteins with formation of complexes, which, as foreign bodies, were preferentially taken up by the cells of the reticuloendothelial system. Depletion of fat stores was probably secondary to increased lipid mobilization, as an attempt by these tissues to supply energy to the parenchymal cells unable to utilize triton-bound lipids.

Animals↗
PubMed1961

Triton hyperlipemia in dogs. I. In vitro effects of the detergent on serum lipoproteins and chylomcrons.

Triton WR-1339, a non-ionic detergent, added to canine serum or to ultracentrifugally separated lipoproteins, induced changes in the lipoproteins which were dependent upon concentration of detergent and class of lipoproteins. D 1.063 to 1.21 lipoprotein (alpha-LP) was especially sensitive to the action of triton. Addition of 2 mg. of triton to 1 mg. of alpha-LP (based on protein content), induced only slight changes in the electrophoretic and flotation characteristics of the lipoprotein. With a tenfold increase of the detergent (triton:alpha-LP, 20:1), the mixture, analyzed by starch gel and paper electrophoresis, yielded a tritonlipid complex which remained close to the origin, and a nearly lipid-free protein with electrophoretic mobility higher (starch gel) or lower (paper) than native alpha-LP. The splitting of the lipid and protein moieties of alpha-LP could not be clearly shown when the same mixture was analyzed by free boundary electrophoresis. Triton alone moved only slightly in an electrical field (paper, starch gel, Tiselius); it sedimented during ultracentrifugation at D 1.006 and D 1.063 and floated at D 1.21. D 1.006 to 1.063 lipoproteins (beta-LP), required larger amounts of triton to show changes. These were evident in 40 to 80:1 mixtures of triton and beta-LP. In starch gel and paper electrophoresis triton retained, in a position close to the origin, part of the lipids of beta-LP; the remaining beta-LP fraction, impoverished of lipids, had electrophoretic mobility similar to native beta-LP. The triton-lipid complex sedimented at D 1.063. After addition of triton to complexes [chylomicron-alpha-P-I(131)] or [lipomul-alpha-LP-1(131)], the electrophoretic and ultracentrifugal analyses of these mixtures revealed that the labeled protein was removed from the triglyceride component. Triton also prevented the occurrence of the interaction between lipomul and alpha-LP and the hydrolysis of both chylomicrons and lipomul-alpha-LP by lipoprotein lipase. It is postulated that, if the changes in lipoproteins and chylomicrons observed in vitro occur in vivo, they could account, at least in part, for the hyperlipemia which develops in animals following administration of triton.

Animals↗
PubMed1959

Separation and characterization of human serum chylomicrons.

Chylomicrons were separated by low and high speed ultracentrifugation from lipemic sera of human subjects in the absorptive phase. The final chylomicron preparation was free from other serum components and contained a small constant amount of protein, approximately 2 per cent of the chylomicron fraction. Electrophoresis, immunochemical analysis, and absorption experiments identified the protein component as derived from a mixture of beta and alpha(1) serum lipoproteins. Large aliquots of an emulsion of serum freed of chylomicrons and coconut oil were incubated at 37 degrees C. for 2 hours and ultracentrifuged as in the preparation of chylomicrons. The fat particles now showed the presence of minute amounts of beta and alpha(1) serum lipoproteins in almost the same proportion as found in chylomicrons. "Finger prints" of delipidized samples of chylomicrons and particles from serum-coconut oil emulsion gave similar, although not identical patterns. The data on "clearing factor" activity corroborated the finding that serum alpha(1) lipoproteins are contained in chylomicrons and particles from serum-coconut oil emulsion. These two lipide particles, partially delipidized, were both able to activate a "clearing factor" system in vitro, a property exhibited only by intact or partially delipidized alpha(1) serum lipoproteins. Clearing activity was satisfactorily determined by using an emulsion of coconut oil mixed in agar as a substrate to give an opaque gel, in which the diffusing enzyme showed its activity by areas of clearing. The results obtained by this technique were in agreement with those based on fall in optical density and non-esterified fatty acid production. Chemical analysis of serum chylomicrons showed a concentration of cholesterol and phospholipides higher than could be accounted for by the attached beta and alpha(1) serum lipoproteins. On the basis of these results the assumption is made that in the blood stream small amounts of serum lipoproteins, by a process of adsorption, form a complex with the absorbed triglycerides, cholesterol, and phospholipides, to produce chylomicrons.

Cholesterol↗
PubMed1958

Studies on the antigenicity of beta- and alpha-lipoproteins of human serum.

The techniques of agar immunoelectrophoresis and agar double diffusion were applied to the study of the antigenicity of beta- and alpha(1)-lipoproteins separated by ultracentrifugation from normal human sera. The effects of delipidation were also investigated. It was shown that beta- and alpha(1)-lipoproteins are antigenically distinct. For each class of lipoprotein studied, a single antigenic component was demonstrated. In some, but not all, preparations of alpha(1)-lipoprotein a second, small antigenic component was detected, and identified as albumin. Absorption with lipoprotein-free serum or albumin removed this component without changing the lipoprotein band. Delipidation did not affect the antigenicity of either beta- or alpha(1)-lipoproteins. Immunoelectrophoresis, because of its high sensitivity and specificity, provides an additional criterion of purity for antigenic proteins in addition to the data that can be obtained from ultracentrifugal and free electrophoretic analysis.

Antigens↗